[WIP] Add comments to the last commit code #1
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With CONFIG_CFI enabled, the kernel strictly enforces that indirect
function calls use a function pointer type that matches the target
function. I ran into the following type mismatch when running BPF
self-tests:
CFI failure at bpf_obj_free_fields+0x190/0x238 (target:
bpf_crypto_ctx_release+0x0/0x94; expected type: 0xa488ebfc)
Internal error: Oops - CFI: 00000000f2008228 [#1] SMP
...
As bpf_crypto_ctx_release() is also used in BPF programs and using
a void pointer as the argument would make the verifier unhappy, add
a simple stub function with the correct type and register it as the
destructor kfunc instead.
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>
Acked-by: Yonghong Song <yonghong.song@linux.dev>
Tested-by: Viktor Malik <vmalik@redhat.com>
Link: https://lore.kernel.org/r/20260110082548.113748-7-samitolvanen@google.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
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…-search' Donglin Peng says: ==================== Improve the performance of BTF type lookups with binary search From: Donglin Peng <pengdonglin@xiaomi.com> The series addresses the performance limitations of linear search in large BTFs by: 1. Adding BTF permutation support 2. Using resolve_btfids to sort BTF during the build phase 3. Checking BTF sorting 4. Using binary search when looking up types Patch #1 introduces an interface for btf__permute in libbpf to relay out BTF. Patch #2 adds test cases to validate the functionality of btf__permute in base and split BTF scenarios. Patch #3 introduces a new phase in the resolve_btfids tool to sort BTF by name in ascending order. Patches #4-torvalds#7 implement the sorting check and binary search. Patches torvalds#8-torvalds#10 optimize type lookup performance of some functions by skipping anonymous types or invoking btf_find_by_name_kind. Patch torvalds#11 refactors the code by calling str_is_empty. Here is a simple performance test result [1] for lookups to find 87,584 named types in vmlinux BTF: ./vmtest.sh -- ./test_progs -t btf_permute/perf -v Results: | Condition | Lookup Time | Improvement | |--------------------|-------------|--------------| | Unsorted (Linear) | 36,534 ms | Baseline | | Sorted (Binary) | 15 ms | 2437x faster | The binary search implementation reduces lookup time from 36.5 seconds to 15 milliseconds, achieving a **2437x** speedup for large-scale type queries. Changelog: v12: - Set the start_id to 1 instead of btf->start_id in the btf__find_by_name (AI) v11: - Link: https://lore.kernel.org/bpf/20260108031645.1350069-1-dolinux.peng@gmail.com/ - PATCH #1: Modify implementation of btf__permute: id_map[0] must be 0 for base BTF (Andrii) - PATCH #3: Refactor the code (Andrii) - PATCH #4~8: - Revert to using the binary search in v7 to simplify the code (Andrii) - Refactor the code of btf_check_sorted (Andrii, Eduard) - Rename sorted_start_id to named_start_id - Rename btf_sorted_start_id to btf_named_start_id, and add comments (Andrii, Eduard) v10: - Link: https://lore.kernel.org/all/20251218113051.455293-1-dolinux.peng@gmail.com/ - Improve btf__permute() documentation (Eduard) - Fall back to linear search when locating anonymous types (Eduard) - Remove redundant NULL name check in libbpf's linear search path (Eduard) - Simplify btf_check_sorted() implementation (Eduard) - Treat kernel modules as unsorted by default - Introduce btf_is_sorted and btf_sorted_start_id for clarity (Eduard) - Fix optimizations in btf_find_decl_tag_value() and btf_prepare_func_args() to support split BTF - Remove linear search branch in determine_ptr_size() - Rebase onto Ihor's v4 patch series [4] v9: - Link: https://lore.kernel.org/bpf/20251208062353.1702672-1-dolinux.peng@gmail.com/ - Optimize the performance of the function determine_ptr_size by invoking btf__find_by_name_kind - Optimize the performance of btf_find_decl_tag_value/btf_prepare_func_args/ bpf_core_add_cands by skipping anonymous types - Rebase the patch series onto Ihor's v3 patch series [3] v8 - Link: https://lore.kernel.org/bpf/20251126085025.784288-1-dolinux.peng@gmail.com/ - Remove the type dropping feature of btf__permute (Andrii) - Refactor the code of btf__permute (Andrii, Eduard) - Make the self-test code cleaner (Eduard) - Reconstruct the BTF sorting patch based on Ihor's patch series [2] - Simplify the sorting logic and place anonymous types before named types (Andrii, Eduard) - Optimize type lookup performance of two kernel functions - Refactoring the binary search and type lookup logic achieves a 4.2% performance gain, reducing the average lookup time (via the perf test code in [1] for 60,995 named types in vmlinux BTF) from 10,217 us (v7) to 9,783 us (v8). v7: - Link: https://lore.kernel.org/all/20251119031531.1817099-1-dolinux.peng@gmail.com/ - btf__permute API refinement: Adjusted id_map and id_map_cnt parameter usage so that for base BTF, id_map[0] now contains the new id of original type id 1 (instead of VOID type id 0), improving logical consistency - Selftest updates: Modified test cases to align with the API usage changes - Refactor the code of resolve_btfids v6: - Link: https://lore.kernel.org/all/20251117132623.3807094-1-dolinux.peng@gmail.com/ - ID Map-based reimplementation of btf__permute (Andrii) - Build-time BTF sorting using resolve_btfids (Alexei, Eduard) - Binary search method refactoring (Andrii) - Enhanced selftest coverage v5: - Link: https://lore.kernel.org/all/20251106131956.1222864-1-dolinux.peng@gmail.com/ - Refactor binary search implementation for improved efficiency (Thanks to Andrii and Eduard) - Extend btf__permute interface with 'ids_sz' parameter to support type dropping feature (suggested by Andrii). Plan subsequent reimplementation of id_map version for comparative analysis with current sequence interface - Add comprehensive test coverage for type dropping functionality - Enhance function comment clarity and accuracy v4: - Link: https://lore.kernel.org/all/20251104134033.344807-1-dolinux.peng@gmail.com/ - Abstracted btf_dedup_remap_types logic into a helper function (suggested by Eduard). - Removed btf_sort.c and implemented sorting separately for libbpf and kernel (suggested by Andrii). - Added test cases for both base BTF and split BTF scenarios (suggested by Eduard). - Added validation for name-only sorting of types (suggested by Andrii) - Refactored btf__permute implementation to reduce complexity (suggested by Andrii) - Add doc comments for btf__permute (suggested by Andrii) v3: - Link: https://lore.kernel.org/all/20251027135423.3098490-1-dolinux.peng@gmail.com/ - Remove sorting logic from libbpf and provide a generic btf__permute() interface (suggested by Andrii) - Omitted the search direction patch to avoid conflicts with base BTF (suggested by Eduard). - Include btf_sort.c directly in btf.c to reduce function call overhead v2: - Link: https://lore.kernel.org/all/20251020093941.548058-1-dolinux.peng@gmail.com/ - Moved sorting to the build phase to reduce overhead (suggested by Alexei). - Integrated sorting into btf_dedup_compact_and_sort_types (suggested by Eduard). - Added sorting checks during BTF parsing. - Consolidated common logic into btf_sort.c for sharing (suggested by Alan). v1: - Link: https://lore.kernel.org/all/20251013131537.1927035-1-dolinux.peng@gmail.com/ [1] https://github.com/pengdonglin137/btf_sort_test [2] https://lore.kernel.org/bpf/20251126012656.3546071-1-ihor.solodrai@linux.dev/ [3] https://lore.kernel.org/bpf/20251205223046.4155870-1-ihor.solodrai@linux.dev/ [4] https://lore.kernel.org/bpf/20251218003314.260269-1-ihor.solodrai@linux.dev/ ==================== Link: https://patch.msgid.link/20260109130003.3313716-1-dolinux.peng@gmail.com Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
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prp_get_untagged_frame() calls __pskb_copy() to create frame->skb_std but doesn't check if the allocation failed. If __pskb_copy() returns NULL, skb_clone() is called with a NULL pointer, causing a crash: Oops: general protection fault, probably for non-canonical address 0xdffffc000000000f: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000078-0x000000000000007f] CPU: 0 UID: 0 PID: 5625 Comm: syz.1.18 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:skb_clone+0xd7/0x3a0 net/core/skbuff.c:2041 Code: 03 42 80 3c 20 00 74 08 4c 89 f7 e8 23 29 05 f9 49 83 3e 00 0f 85 a0 01 00 00 e8 94 dd 9d f8 48 8d 6b 7e 49 89 ee 49 c1 ee 03 <43> 0f b6 04 26 84 c0 0f 85 d1 01 00 00 44 0f b6 7d 00 41 83 e7 0c RSP: 0018:ffffc9000d00f200 EFLAGS: 00010207 RAX: ffffffff892235a1 RBX: 0000000000000000 RCX: ffff88803372a480 RDX: 0000000000000000 RSI: 0000000000000820 RDI: 0000000000000000 RBP: 000000000000007e R08: ffffffff8f7d0f77 R09: 1ffffffff1efa1ee R10: dffffc0000000000 R11: fffffbfff1efa1ef R12: dffffc0000000000 R13: 0000000000000820 R14: 000000000000000f R15: ffff88805144cc00 FS: 0000555557f6d500(0000) GS:ffff88808d72f000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555581d35808 CR3: 000000005040e000 CR4: 0000000000352ef0 Call Trace: <TASK> hsr_forward_do net/hsr/hsr_forward.c:-1 [inline] hsr_forward_skb+0x1013/0x2860 net/hsr/hsr_forward.c:741 hsr_handle_frame+0x6ce/0xa70 net/hsr/hsr_slave.c:84 __netif_receive_skb_core+0x10b9/0x4380 net/core/dev.c:5966 __netif_receive_skb_one_core net/core/dev.c:6077 [inline] __netif_receive_skb+0x72/0x380 net/core/dev.c:6192 netif_receive_skb_internal net/core/dev.c:6278 [inline] netif_receive_skb+0x1cb/0x790 net/core/dev.c:6337 tun_rx_batched+0x1b9/0x730 drivers/net/tun.c:1485 tun_get_user+0x2b65/0x3e90 drivers/net/tun.c:1953 tun_chr_write_iter+0x113/0x200 drivers/net/tun.c:1999 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0449f8e1ff Code: 89 54 24 18 48 89 74 24 10 89 7c 24 08 e8 f9 92 02 00 48 8b 54 24 18 48 8b 74 24 10 41 89 c0 8b 7c 24 08 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 31 44 89 c7 48 89 44 24 08 e8 4c 93 02 00 48 RSP: 002b:00007ffd7ad94c90 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f044a1e5fa0 RCX: 00007f0449f8e1ff RDX: 000000000000003e RSI: 0000200000000500 RDI: 00000000000000c8 RBP: 00007ffd7ad94d20 R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000003e R11: 0000000000000293 R12: 0000000000000001 R13: 00007f044a1e5fa0 R14: 00007f044a1e5fa0 R15: 0000000000000003 </TASK> Add a NULL check immediately after __pskb_copy() to handle allocation failures gracefully. Reported-by: syzbot+2fa344348a579b779e05@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2fa344348a579b779e05 Fixes: f266a68 ("net/hsr: Better frame dispatch") Cc: stable@vger.kernel.org Signed-off-by: Shaurya Rane <ssrane_b23@ee.vjti.ac.in> Reviewed-by: Felix Maurer <fmaurer@redhat.com> Tested-by: Felix Maurer <fmaurer@redhat.com> Link: https://patch.msgid.link/20251129093718.25320-1-ssrane_b23@ee.vjti.ac.in Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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…in ets_qdisc_change
zdi-disclosures@trendmicro.com says:
The vulnerability is a race condition between `ets_qdisc_dequeue` and
`ets_qdisc_change`. It leads to UAF on `struct Qdisc` object.
Attacker requires the capability to create new user and network namespace
in order to trigger the bug.
See my additional commentary at the end of the analysis.
Analysis:
static int ets_qdisc_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
...
// (1) this lock is preventing .change handler (`ets_qdisc_change`)
//to race with .dequeue handler (`ets_qdisc_dequeue`)
sch_tree_lock(sch);
for (i = nbands; i < oldbands; i++) {
if (i >= q->nstrict && q->classes[i].qdisc->q.qlen)
list_del_init(&q->classes[i].alist);
qdisc_purge_queue(q->classes[i].qdisc);
}
WRITE_ONCE(q->nbands, nbands);
for (i = nstrict; i < q->nstrict; i++) {
if (q->classes[i].qdisc->q.qlen) {
// (2) the class is added to the q->active
list_add_tail(&q->classes[i].alist, &q->active);
q->classes[i].deficit = quanta[i];
}
}
WRITE_ONCE(q->nstrict, nstrict);
memcpy(q->prio2band, priomap, sizeof(priomap));
for (i = 0; i < q->nbands; i++)
WRITE_ONCE(q->classes[i].quantum, quanta[i]);
for (i = oldbands; i < q->nbands; i++) {
q->classes[i].qdisc = queues[i];
if (q->classes[i].qdisc != &noop_qdisc)
qdisc_hash_add(q->classes[i].qdisc, true);
}
// (3) the qdisc is unlocked, now dequeue can be called in parallel
// to the rest of .change handler
sch_tree_unlock(sch);
ets_offload_change(sch);
for (i = q->nbands; i < oldbands; i++) {
// (4) we're reducing the refcount for our class's qdisc and
// freeing it
qdisc_put(q->classes[i].qdisc);
// (5) If we call .dequeue between (4) and (5), we will have
// a strong UAF and we can control RIP
q->classes[i].qdisc = NULL;
WRITE_ONCE(q->classes[i].quantum, 0);
q->classes[i].deficit = 0;
gnet_stats_basic_sync_init(&q->classes[i].bstats);
memset(&q->classes[i].qstats, 0, sizeof(q->classes[i].qstats));
}
return 0;
}
Comment:
This happens because some of the classes have their qdiscs assigned to
NULL, but remain in the active list. This commit fixes this issue by always
removing the class from the active list before deleting and freeing its
associated qdisc
Reproducer Steps
(trimmed version of what was sent by zdi-disclosures@trendmicro.com)
```
DEV="${DEV:-lo}"
ROOT_HANDLE="${ROOT_HANDLE:-1:}"
BAND2_HANDLE="${BAND2_HANDLE:-20:}" # child under 1:2
PING_BYTES="${PING_BYTES:-48}"
PING_COUNT="${PING_COUNT:-200000}"
PING_DST="${PING_DST:-127.0.0.1}"
SLOW_TBF_RATE="${SLOW_TBF_RATE:-8bit}"
SLOW_TBF_BURST="${SLOW_TBF_BURST:-100b}"
SLOW_TBF_LAT="${SLOW_TBF_LAT:-1s}"
cleanup() {
tc qdisc del dev "$DEV" root 2>/dev/null
}
trap cleanup EXIT
ip link set "$DEV" up
tc qdisc del dev "$DEV" root 2>/dev/null || true
tc qdisc add dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc qdisc add dev "$DEV" parent 1:2 handle "$BAND2_HANDLE" \
tbf rate "$SLOW_TBF_RATE" burst "$SLOW_TBF_BURST" latency "$SLOW_TBF_LAT"
tc filter add dev "$DEV" parent 1: protocol all prio 1 u32 match u32 0 0 flowid 1:2
tc -s qdisc ls dev $DEV
ping -I "$DEV" -f -c "$PING_COUNT" -s "$PING_BYTES" -W 0.001 "$PING_DST" \
>/dev/null 2>&1 &
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 0
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 2 strict 2
tc -s qdisc ls dev $DEV
tc qdisc del dev "$DEV" parent 1:2 || true
tc -s qdisc ls dev $DEV
tc qdisc change dev "$DEV" root handle "$ROOT_HANDLE" ets bands 1 strict 1
```
KASAN report
```
==================================================================
BUG: KASAN: slab-use-after-free in ets_qdisc_dequeue+0x1071/0x11b0 kernel/net/sched/sch_ets.c:481
Read of size 8 at addr ffff8880502fc018 by task ping/12308
>
CPU: 0 UID: 0 PID: 12308 Comm: ping Not tainted 6.18.0-rc4-dirty #1 PREEMPT(full)
Hardware name: QEMU Ubuntu 25.04 PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
<IRQ>
__dump_stack kernel/lib/dump_stack.c:94
dump_stack_lvl+0x100/0x190 kernel/lib/dump_stack.c:120
print_address_description kernel/mm/kasan/report.c:378
print_report+0x156/0x4c9 kernel/mm/kasan/report.c:482
kasan_report+0xdf/0x110 kernel/mm/kasan/report.c:595
ets_qdisc_dequeue+0x1071/0x11b0 kernel/net/sched/sch_ets.c:481
dequeue_skb kernel/net/sched/sch_generic.c:294
qdisc_restart kernel/net/sched/sch_generic.c:399
__qdisc_run+0x1c9/0x1b00 kernel/net/sched/sch_generic.c:417
__dev_xmit_skb kernel/net/core/dev.c:4221
__dev_queue_xmit+0x2848/0x4410 kernel/net/core/dev.c:4729
dev_queue_xmit kernel/./include/linux/netdevice.h:3365
[...]
Allocated by task 17115:
kasan_save_stack+0x30/0x50 kernel/mm/kasan/common.c:56
kasan_save_track+0x14/0x30 kernel/mm/kasan/common.c:77
poison_kmalloc_redzone kernel/mm/kasan/common.c:400
__kasan_kmalloc+0xaa/0xb0 kernel/mm/kasan/common.c:417
kasan_kmalloc kernel/./include/linux/kasan.h:262
__do_kmalloc_node kernel/mm/slub.c:5642
__kmalloc_node_noprof+0x34e/0x990 kernel/mm/slub.c:5648
kmalloc_node_noprof kernel/./include/linux/slab.h:987
qdisc_alloc+0xb8/0xc30 kernel/net/sched/sch_generic.c:950
qdisc_create_dflt+0x93/0x490 kernel/net/sched/sch_generic.c:1012
ets_class_graft+0x4fd/0x800 kernel/net/sched/sch_ets.c:261
qdisc_graft+0x3e4/0x1780 kernel/net/sched/sch_api.c:1196
[...]
Freed by task 9905:
kasan_save_stack+0x30/0x50 kernel/mm/kasan/common.c:56
kasan_save_track+0x14/0x30 kernel/mm/kasan/common.c:77
__kasan_save_free_info+0x3b/0x70 kernel/mm/kasan/generic.c:587
kasan_save_free_info kernel/mm/kasan/kasan.h:406
poison_slab_object kernel/mm/kasan/common.c:252
__kasan_slab_free+0x5f/0x80 kernel/mm/kasan/common.c:284
kasan_slab_free kernel/./include/linux/kasan.h:234
slab_free_hook kernel/mm/slub.c:2539
slab_free kernel/mm/slub.c:6630
kfree+0x144/0x700 kernel/mm/slub.c:6837
rcu_do_batch kernel/kernel/rcu/tree.c:2605
rcu_core+0x7c0/0x1500 kernel/kernel/rcu/tree.c:2861
handle_softirqs+0x1ea/0x8a0 kernel/kernel/softirq.c:622
__do_softirq kernel/kernel/softirq.c:656
[...]
Commentary:
1. Maher Azzouzi working with Trend Micro Zero Day Initiative was reported as
the person who found the issue. I requested to get a proper email to add to the
reported-by tag but got no response. For this reason i will credit the person
i exchanged emails with i.e zdi-disclosures@trendmicro.com
2. Neither i nor Victor who did a much more thorough testing was able to
reproduce a UAF with the PoC or other approaches we tried. We were both able to
reproduce a null ptr deref. After exchange with zdi-disclosures@trendmicro.com
they sent a small change to be made to the code to add an extra delay which
was able to simulate the UAF. i.e, this:
qdisc_put(q->classes[i].qdisc);
mdelay(90);
q->classes[i].qdisc = NULL;
I was informed by Thomas Gleixner(tglx@linutronix.de) that adding delays was
acceptable approach for demonstrating the bug, quote:
"Adding such delays is common exploit validation practice"
The equivalent delay could happen "by virt scheduling the vCPU out, SMIs,
NMIs, PREEMPT_RT enabled kernel"
3. I asked the OP to test and report back but got no response and after a
few days gave up and proceeded to submit this fix.
Fixes: de6d259 ("net/sched: sch_ets: don't peek at classes beyond 'nbands'")
Reported-by: zdi-disclosures@trendmicro.com
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Reviewed-by: Davide Caratti <dcaratti@redhat.com>
Link: https://patch.msgid.link/20251128151919.576920-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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Clear hca_devcom_comp in device's private data after unregistering it in LAG teardown. Otherwise a slightly lagging second pass through mlx5_unload_one() might try to unregister it again and trip over use-after-free. On s390 almost all PCI level recovery events trigger two passes through mxl5_unload_one() - one through the poll_health() method and one through mlx5_pci_err_detected() as callback from generic PCI error recovery. While testing PCI error recovery paths with more kernel debug features enabled, this issue reproducibly led to kernel panics with the following call chain: Unable to handle kernel pointer dereference in virtual kernel address space Failing address: 6b6b6b6b6b6b6000 TEID: 6b6b6b6b6b6b6803 ESOP-2 FSI Fault in home space mode while using kernel ASCE. AS:00000000705c4007 R3:0000000000000024 Oops: 0038 ilc:3 [#1]SMP CPU: 14 UID: 0 PID: 156 Comm: kmcheck Kdump: loaded Not tainted 6.18.0-20251130.rc7.git0.16131a59cab1.300.fc43.s390x+debug #1 PREEMPT Krnl PSW : 0404e00180000000 0000020fc86aa1dc (__lock_acquire+0x5c/0x15f0) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:2 PM:0 RI:0 EA:3 Krnl GPRS: 0000000000000000 0000020f00000001 6b6b6b6b6b6b6c33 0000000000000000 0000000000000000 0000000000000000 0000000000000001 0000000000000000 0000000000000000 0000020fca28b820 0000000000000000 0000010a1ced8100 0000010a1ced8100 0000020fc9775068 0000018fce14f8b8 0000018fce14f7f8 Krnl Code: 0000020fc86aa1cc: e3b003400004 lg %r11,832 0000020fc86aa1d2: a7840211 brc 8,0000020fc86aa5f4 *0000020fc86aa1d6: c09000df0b25 larl %r9,0000020fca28b820 >0000020fc86aa1dc: d50790002000 clc 0(8,%r9),0(%r2) 0000020fc86aa1e2: a7840209 brc 8,0000020fc86aa5f4 0000020fc86aa1e6: c0e001100401 larl %r14,0000020fca8aa9e8 0000020fc86aa1ec: c01000e25a00 larl %r1,0000020fca2f55ec 0000020fc86aa1f2: a7eb00e8 aghi %r14,232 Call Trace: __lock_acquire+0x5c/0x15f0 lock_acquire.part.0+0xf8/0x270 lock_acquire+0xb0/0x1b0 down_write+0x5a/0x250 mlx5_detach_device+0x42/0x110 [mlx5_core] mlx5_unload_one_devl_locked+0x50/0xc0 [mlx5_core] mlx5_unload_one+0x42/0x60 [mlx5_core] mlx5_pci_err_detected+0x94/0x150 [mlx5_core] zpci_event_attempt_error_recovery+0xcc/0x388 Fixes: 5a977b5 ("net/mlx5: Lag, move devcom registration to LAG layer") Signed-off-by: Gerd Bayer <gbayer@linux.ibm.com> Reviewed-by: Moshe Shemesh <moshe@nvidia.com> Acked-by: Tariq Toukan <tariqt@nvidia.com> Link: https://patch.msgid.link/20251202-fix_lag-v1-1-59e8177ffce0@linux.ibm.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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…stats Cited commit added a dedicated mutex (instead of RTNL) to protect the multicast route list, so that it will not change while the driver periodically traverses it in order to update the kernel about multicast route stats that were queried from the device. One instance of list entry deletion (during route replace) was missed and it can result in a use-after-free [1]. Fix by acquiring the mutex before deleting the entry from the list and releasing it afterwards. [1] BUG: KASAN: slab-use-after-free in mlxsw_sp_mr_stats_update+0x4a5/0x540 drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:1006 [mlxsw_spectrum] Read of size 8 at addr ffff8881523c2fa8 by task kworker/2:5/22043 CPU: 2 UID: 0 PID: 22043 Comm: kworker/2:5 Not tainted 6.18.0-rc1-custom-g1a3d6d7cd014 #1 PREEMPT(full) Hardware name: Mellanox Technologies Ltd. MSN2010/SA002610, BIOS 5.6.5 08/24/2017 Workqueue: mlxsw_core mlxsw_sp_mr_stats_update [mlxsw_spectrum] Call Trace: <TASK> dump_stack_lvl+0xba/0x110 print_report+0x174/0x4f5 kasan_report+0xdf/0x110 mlxsw_sp_mr_stats_update+0x4a5/0x540 drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:1006 [mlxsw_spectrum] process_one_work+0x9cc/0x18e0 worker_thread+0x5df/0xe40 kthread+0x3b8/0x730 ret_from_fork+0x3e9/0x560 ret_from_fork_asm+0x1a/0x30 </TASK> Allocated by task 29933: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_kmalloc+0x8f/0xa0 mlxsw_sp_mr_route_add+0xd8/0x4770 [mlxsw_spectrum] mlxsw_sp_router_fibmr_event_work+0x371/0xad0 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:7965 [mlxsw_spectrum] process_one_work+0x9cc/0x18e0 worker_thread+0x5df/0xe40 kthread+0x3b8/0x730 ret_from_fork+0x3e9/0x560 ret_from_fork_asm+0x1a/0x30 Freed by task 29933: kasan_save_stack+0x30/0x50 kasan_save_track+0x14/0x30 __kasan_save_free_info+0x3b/0x70 __kasan_slab_free+0x43/0x70 kfree+0x14e/0x700 mlxsw_sp_mr_route_add+0x2dea/0x4770 drivers/net/ethernet/mellanox/mlxsw/spectrum_mr.c:444 [mlxsw_spectrum] mlxsw_sp_router_fibmr_event_work+0x371/0xad0 drivers/net/ethernet/mellanox/mlxsw/spectrum_router.c:7965 [mlxsw_spectrum] process_one_work+0x9cc/0x18e0 worker_thread+0x5df/0xe40 kthread+0x3b8/0x730 ret_from_fork+0x3e9/0x560 ret_from_fork_asm+0x1a/0x30 Fixes: f38656d ("mlxsw: spectrum_mr: Protect multicast route list with a lock") Signed-off-by: Ido Schimmel <idosch@nvidia.com> Reviewed-by: Petr Machata <petrm@nvidia.com> Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/f996feecfd59fde297964bfc85040b6d83ec6089.1764695650.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Jakub reported an MPTCP deadlock at fallback time: WARNING: possible recursive locking detected 6.18.0-rc7-virtme #1 Not tainted -------------------------------------------- mptcp_connect/20858 is trying to acquire lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_try_fallback+0xd8/0x280 but task is already holding lock: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&msk->fallback_lock); lock(&msk->fallback_lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by mptcp_connect/20858: #0: ff1100001da18290 (sk_lock-AF_INET){+.+.}-{0:0}, at: mptcp_sendmsg+0x114/0x1bc0 #1: ff1100001db40fd0 (k-sk_lock-AF_INET#2){+.+.}-{0:0}, at: __mptcp_retrans+0x2cb/0xaa0 #2: ff1100001da18b60 (&msk->fallback_lock){+.-.}-{3:3}, at: __mptcp_retrans+0x352/0xaa0 stack backtrace: CPU: 0 UID: 0 PID: 20858 Comm: mptcp_connect Not tainted 6.18.0-rc7-virtme #1 PREEMPT(full) Hardware name: Bochs, BIOS Bochs 01/01/2011 Call Trace: <TASK> dump_stack_lvl+0x6f/0xa0 print_deadlock_bug.cold+0xc0/0xcd validate_chain+0x2ff/0x5f0 __lock_acquire+0x34c/0x740 lock_acquire.part.0+0xbc/0x260 _raw_spin_lock_bh+0x38/0x50 __mptcp_try_fallback+0xd8/0x280 mptcp_sendmsg_frag+0x16c2/0x3050 __mptcp_retrans+0x421/0xaa0 mptcp_release_cb+0x5aa/0xa70 release_sock+0xab/0x1d0 mptcp_sendmsg+0xd5b/0x1bc0 sock_write_iter+0x281/0x4d0 new_sync_write+0x3c5/0x6f0 vfs_write+0x65e/0xbb0 ksys_write+0x17e/0x200 do_syscall_64+0xbb/0xfd0 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7fa5627cbc5e Code: 4d 89 d8 e8 14 bd 00 00 4c 8b 5d f8 41 8b 93 08 03 00 00 59 5e 48 83 f8 fc 74 11 c9 c3 0f 1f 80 00 00 00 00 48 8b 45 10 0f 05 <c9> c3 83 e2 39 83 fa 08 75 e7 e8 13 ff ff ff 0f 1f 00 f3 0f 1e fa RSP: 002b:00007fff1fe14700 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000005 RCX: 00007fa5627cbc5e RDX: 0000000000001f9c RSI: 00007fff1fe16984 RDI: 0000000000000005 RBP: 00007fff1fe14710 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00007fff1fe16920 R13: 0000000000002000 R14: 0000000000001f9c R15: 0000000000001f9c The packet scheduler could attempt a reinjection after receiving an MP_FAIL and before the infinite map has been transmitted, causing a deadlock since MPTCP needs to do the reinjection atomically from WRT fallback. Address the issue explicitly avoiding the reinjection in the critical scenario. Note that this is the only fallback critical section that could potentially send packets and hit the double-lock. Reported-by: Jakub Kicinski <kuba@kernel.org> Closes: https://netdev-ctrl.bots.linux.dev/logs/vmksft/mptcp-dbg/results/412720/1-mptcp-join-sh/stderr Fixes: f8a1d9b ("mptcp: make fallback action and fallback decision atomic") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251205-net-mptcp-misc-fixes-6-19-rc1-v1-4-9e4781a6c1b8@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Petr Machata says: ==================== selftests: forwarding: vxlan_bridge_1q_mc_ul: Fix flakiness The net/forwarding/vxlan_bridge_1q_mc_ul selftest runs an overlay traffic, forwarded over a multicast-routed VXLAN underlay. In order to determine whether packets reach their intended destination, it uses a TC match. For convenience, it uses a flower match, which however does not allow matching on the encapsulated packet. So various service traffic ends up being indistinguishable from the test packets, and ends up confusing the test. To alleviate the problem, the test uses sleep to allow the necessary service traffic to run and clear the channel, before running the test traffic. This worked for a while, but lately we have nevertheless seen flakiness of the test in the CI. In this patchset, first generalize tc_rule_stats_get() to support u32 in patch #1, then in patch #2 convert the test to use u32 to allow parsing deeper into the packet, and in #3 drop the now-unnecessary sleep. ==================== Link: https://patch.msgid.link/cover.1765289566.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Fix a loop scenario of ethx:egress->ethx:egress
Example setup to reproduce:
tc qdisc add dev ethx root handle 1: drr
tc filter add dev ethx parent 1: protocol ip prio 1 matchall \
action mirred egress redirect dev ethx
Now ping out of ethx and you get a deadlock:
[ 116.892898][ T307] ============================================
[ 116.893182][ T307] WARNING: possible recursive locking detected
[ 116.893418][ T307] 6.18.0-rc6-01205-ge05021a829b8-dirty torvalds#204 Not tainted
[ 116.893682][ T307] --------------------------------------------
[ 116.893926][ T307] ping/307 is trying to acquire lock:
[ 116.894133][ T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[ 116.894517][ T307]
[ 116.894517][ T307] but task is already holding lock:
[ 116.894836][ T307] ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[ 116.895252][ T307]
[ 116.895252][ T307] other info that might help us debug this:
[ 116.895608][ T307] Possible unsafe locking scenario:
[ 116.895608][ T307]
[ 116.895901][ T307] CPU0
[ 116.896057][ T307] ----
[ 116.896200][ T307] lock(&sch->root_lock_key);
[ 116.896392][ T307] lock(&sch->root_lock_key);
[ 116.896605][ T307]
[ 116.896605][ T307] *** DEADLOCK ***
[ 116.896605][ T307]
[ 116.896864][ T307] May be due to missing lock nesting notation
[ 116.896864][ T307]
[ 116.897123][ T307] 6 locks held by ping/307:
[ 116.897302][ T307] #0: ffff88800b4b0250 (sk_lock-AF_INET){+.+.}-{0:0}, at: raw_sendmsg+0xb20/0x2cf0
[ 116.897808][ T307] #1: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_output+0xa9/0x600
[ 116.898138][ T307] #2: ffffffff88c839c0 (rcu_read_lock){....}-{1:3}, at: ip_finish_output2+0x2c6/0x1ee0
[ 116.898459][ T307] #3: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50
[ 116.898782][ T307] #4: ffff88800c122908 (&sch->root_lock_key){+...}-{3:3}, at: __dev_queue_xmit+0x2210/0x3b50
[ 116.899132][ T307] #5: ffffffff88c83960 (rcu_read_lock_bh){....}-{1:3}, at: __dev_queue_xmit+0x200/0x3b50
[ 116.899442][ T307]
[ 116.899442][ T307] stack backtrace:
[ 116.899667][ T307] CPU: 2 UID: 0 PID: 307 Comm: ping Not tainted 6.18.0-rc6-01205-ge05021a829b8-dirty torvalds#204 PREEMPT(voluntary)
[ 116.899672][ T307] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[ 116.899675][ T307] Call Trace:
[ 116.899678][ T307] <TASK>
[ 116.899680][ T307] dump_stack_lvl+0x6f/0xb0
[ 116.899688][ T307] print_deadlock_bug.cold+0xc0/0xdc
[ 116.899695][ T307] __lock_acquire+0x11f7/0x1be0
[ 116.899704][ T307] lock_acquire+0x162/0x300
[ 116.899707][ T307] ? __dev_queue_xmit+0x2210/0x3b50
[ 116.899713][ T307] ? srso_alias_return_thunk+0x5/0xfbef5
[ 116.899717][ T307] ? stack_trace_save+0x93/0xd0
[ 116.899723][ T307] _raw_spin_lock+0x30/0x40
[ 116.899728][ T307] ? __dev_queue_xmit+0x2210/0x3b50
[ 116.899731][ T307] __dev_queue_xmit+0x2210/0x3b50
Fixes: 178ca30 ("Revert "net/sched: Fix mirred deadlock on device recursion"")
Tested-by: Victor Nogueira <victor@mojatatu.com>
Signed-off-by: Jamal Hadi Salim <jhs@mojatatu.com>
Link: https://patch.msgid.link/20251210162255.1057663-1-jhs@mojatatu.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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With the RAPL PMU addition, there is a recursive locking when CPU online callback function calls rapl_package_add_pmu(). Here cpu_hotplug_lock is already acquired by cpuhp_thread_fun() and rapl_package_add_pmu() tries to acquire again. <4>[ 8.197433] ============================================ <4>[ 8.197437] WARNING: possible recursive locking detected <4>[ 8.197440] 6.19.0-rc1-lgci-xe-xe-4242-05b7c58b3367dca84+ #1 Not tainted <4>[ 8.197444] -------------------------------------------- <4>[ 8.197447] cpuhp/0/20 is trying to acquire lock: <4>[ 8.197450] ffffffff83487870 (cpu_hotplug_lock){++++}-{0:0}, at: rapl_package_add_pmu+0x37/0x370 [intel_rapl_common] <4>[ 8.197463] but task is already holding lock: <4>[ 8.197466] ffffffff83487870 (cpu_hotplug_lock){++++}-{0:0}, at: cpuhp_thread_fun+0x6d/0x290 <4>[ 8.197477] other info that might help us debug this: <4>[ 8.197480] Possible unsafe locking scenario: <4>[ 8.197483] CPU0 <4>[ 8.197485] ---- <4>[ 8.197487] lock(cpu_hotplug_lock); <4>[ 8.197490] lock(cpu_hotplug_lock); <4>[ 8.197493] *** DEADLOCK *** .. .. <4>[ 8.197542] __lock_acquire+0x146e/0x2790 <4>[ 8.197548] lock_acquire+0xc4/0x2c0 <4>[ 8.197550] ? rapl_package_add_pmu+0x37/0x370 [intel_rapl_common] <4>[ 8.197556] cpus_read_lock+0x41/0x110 <4>[ 8.197558] ? rapl_package_add_pmu+0x37/0x370 [intel_rapl_common] <4>[ 8.197561] rapl_package_add_pmu+0x37/0x370 [intel_rapl_common] <4>[ 8.197565] rapl_cpu_online+0x85/0x87 [intel_rapl_msr] <4>[ 8.197568] ? __pfx_rapl_cpu_online+0x10/0x10 [intel_rapl_msr] <4>[ 8.197570] cpuhp_invoke_callback+0x41f/0x6c0 <4>[ 8.197573] ? cpuhp_thread_fun+0x6d/0x290 <4>[ 8.197575] cpuhp_thread_fun+0x1e2/0x290 <4>[ 8.197578] ? smpboot_thread_fn+0x26/0x290 <4>[ 8.197581] smpboot_thread_fn+0x12f/0x290 <4>[ 8.197584] ? __pfx_smpboot_thread_fn+0x10/0x10 <4>[ 8.197586] kthread+0x11f/0x250 <4>[ 8.197589] ? __pfx_kthread+0x10/0x10 <4>[ 8.197592] ret_from_fork+0x344/0x3a0 <4>[ 8.197595] ? __pfx_kthread+0x10/0x10 <4>[ 8.197597] ret_from_fork_asm+0x1a/0x30 <4>[ 8.197604] </TASK> Fix this issue in the same way as rapl powercap package domain is added from the same CPU online callback by introducing another interface which doesn't call cpus_read_lock(). Add rapl_package_add_pmu_locked() and rapl_package_remove_pmu_locked() which don't call cpus_read_lock(). Fixes: 748d6ba ("powercap: intel_rapl: Enable MSR-based RAPL PMU support") Reported-by: Borah, Chaitanya Kumar <chaitanya.kumar.borah@intel.com> Closes: https://lore.kernel.org/linux-pm/5427ede1-57a0-43d1-99f3-8ca4b0643e82@intel.com/T/#u Tested-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> Tested-by: RavitejaX Veesam <ravitejax.veesam@intel.com> Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com> Link: https://patch.msgid.link/20251217153455.3560176-1-srinivas.pandruvada@linux.intel.com Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
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Avoid a possible UAF in GPU recovery due to a race between the sched timeout callback and the tdr work queue. The gpu recovery function calls drm_sched_stop() and later drm_sched_start(). drm_sched_start() restarts the tdr queue which will eventually free the job. If the tdr queue frees the job before time out callback completes, the job will be freed and we'll get a UAF when accessing the pasid. Cache it early to avoid the UAF. Example KASAN trace: [ 493.058141] BUG: KASAN: slab-use-after-free in amdgpu_device_gpu_recover+0x968/0x990 [amdgpu] [ 493.067530] Read of size 4 at addr ffff88b0ce3f794c by task kworker/u128:1/323 [ 493.074892] [ 493.076485] CPU: 9 UID: 0 PID: 323 Comm: kworker/u128:1 Tainted: G E 6.16.0-1289896.2.zuul.bf4f11df81c1410bbe901c4373305a31 #1 PREEMPT(voluntary) [ 493.076493] Tainted: [E]=UNSIGNED_MODULE [ 493.076495] Hardware name: TYAN B8021G88V2HR-2T/S8021GM2NR-2T, BIOS V1.03.B10 04/01/2019 [ 493.076500] Workqueue: amdgpu-reset-dev drm_sched_job_timedout [gpu_sched] [ 493.076512] Call Trace: [ 493.076515] <TASK> [ 493.076518] dump_stack_lvl+0x64/0x80 [ 493.076529] print_report+0xce/0x630 [ 493.076536] ? _raw_spin_lock_irqsave+0x86/0xd0 [ 493.076541] ? __pfx__raw_spin_lock_irqsave+0x10/0x10 [ 493.076545] ? amdgpu_device_gpu_recover+0x968/0x990 [amdgpu] [ 493.077253] kasan_report+0xb8/0xf0 [ 493.077258] ? amdgpu_device_gpu_recover+0x968/0x990 [amdgpu] [ 493.077965] amdgpu_device_gpu_recover+0x968/0x990 [amdgpu] [ 493.078672] ? __pfx_amdgpu_device_gpu_recover+0x10/0x10 [amdgpu] [ 493.079378] ? amdgpu_coredump+0x1fd/0x4c0 [amdgpu] [ 493.080111] amdgpu_job_timedout+0x642/0x1400 [amdgpu] [ 493.080903] ? pick_task_fair+0x24e/0x330 [ 493.080910] ? __pfx_amdgpu_job_timedout+0x10/0x10 [amdgpu] [ 493.081702] ? _raw_spin_lock+0x75/0xc0 [ 493.081708] ? __pfx__raw_spin_lock+0x10/0x10 [ 493.081712] drm_sched_job_timedout+0x1b0/0x4b0 [gpu_sched] [ 493.081721] ? __pfx__raw_spin_lock_irq+0x10/0x10 [ 493.081725] process_one_work+0x679/0xff0 [ 493.081732] worker_thread+0x6ce/0xfd0 [ 493.081736] ? __pfx_worker_thread+0x10/0x10 [ 493.081739] kthread+0x376/0x730 [ 493.081744] ? __pfx_kthread+0x10/0x10 [ 493.081748] ? __pfx__raw_spin_lock_irq+0x10/0x10 [ 493.081751] ? __pfx_kthread+0x10/0x10 [ 493.081755] ret_from_fork+0x247/0x330 [ 493.081761] ? __pfx_kthread+0x10/0x10 [ 493.081764] ret_from_fork_asm+0x1a/0x30 [ 493.081771] </TASK> Fixes: a72002c ("drm/amdgpu: Make use of drm_wedge_task_info") Link: HansKristian-Work/vkd3d-proton#2670 Cc: SRINIVASAN.SHANMUGAM@amd.com Cc: vitaly.prosyak@amd.com Cc: christian.koenig@amd.com Suggested-by: Matthew Brost <matthew.brost@intel.com> Reviewed-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> Reviewed-by: Lijo Lazar <lijo.lazar@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 20880a3)
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A race condition was found in sg_proc_debug_helper(). It was observed on a system using an IBM LTO-9 SAS Tape Drive (ULTRIUM-TD9) and monitoring /proc/scsi/sg/debug every second. A very large elapsed time would sometimes appear. This is caused by two race conditions. We reproduced the issue with an IBM ULTRIUM-HH9 tape drive on an x86_64 architecture. A patched kernel was built, and the race condition could not be observed anymore after the application of this patch. A reproducer C program utilising the scsi_debug module was also built by Changhui Zhong and can be viewed here: https://github.com/MichaelRabek/linux-tests/blob/master/drivers/scsi/sg/sg_race_trigger.c The first race happens between the reading of hp->duration in sg_proc_debug_helper() and request completion in sg_rq_end_io(). The hp->duration member variable may hold either of two types of information: #1 - The start time of the request. This value is present while the request is not yet finished. #2 - The total execution time of the request (end_time - start_time). If sg_proc_debug_helper() executes *after* the value of hp->duration was changed from #1 to #2, but *before* srp->done is set to 1 in sg_rq_end_io(), a fresh timestamp is taken in the else branch, and the elapsed time (value type #2) is subtracted from a timestamp, which cannot yield a valid elapsed time (which is a type #2 value as well). To fix this issue, the value of hp->duration must change under the protection of the sfp->rq_list_lock in sg_rq_end_io(). Since sg_proc_debug_helper() takes this read lock, the change to srp->done and srp->header.duration will happen atomically from the perspective of sg_proc_debug_helper() and the race condition is thus eliminated. The second race condition happens between sg_proc_debug_helper() and sg_new_write(). Even though hp->duration is set to the current time stamp in sg_add_request() under the write lock's protection, it gets overwritten by a call to get_sg_io_hdr(), which calls copy_from_user() to copy struct sg_io_hdr from userspace into kernel space. hp->duration is set to the start time again in sg_common_write(). If sg_proc_debug_helper() is called between these two calls, an arbitrary value set by userspace (usually zero) is used to compute the elapsed time. To fix this issue, hp->duration must be set to the current timestamp again after get_sg_io_hdr() returns successfully. A small race window still exists between get_sg_io_hdr() and setting hp->duration, but this window is only a few instructions wide and does not result in observable issues in practice, as confirmed by testing. Additionally, we fix the format specifier from %d to %u for printing unsigned int values in sg_proc_debug_helper(). Signed-off-by: Michal Rábek <mrabek@redhat.com> Suggested-by: Tomas Henzl <thenzl@redhat.com> Tested-by: Changhui Zhong <czhong@redhat.com> Reviewed-by: Ewan D. Milne <emilne@redhat.com> Reviewed-by: John Meneghini <jmeneghi@redhat.com> Reviewed-by: Tomas Henzl <thenzl@redhat.com> Link: https://patch.msgid.link/20251212160900.64924-1-mrabek@redhat.com Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
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Jan 16, 2026
When a page is freed it coalesces with a buddy into a higher order page while possible. When the buddy page migrate type differs, it is expected to be updated to match the one of the page being freed. However, only the first pageblock of the buddy page is updated, while the rest of the pageblocks are left unchanged. That causes warnings in later expand() and other code paths (like below), since an inconsistency between migration type of the list containing the page and the page-owned pageblocks migration types is introduced. [ 308.986589] ------------[ cut here ]------------ [ 308.987227] page type is 0, passed migratetype is 1 (nr=256) [ 308.987275] WARNING: CPU: 1 PID: 5224 at mm/page_alloc.c:812 expand+0x23c/0x270 [ 308.987293] Modules linked in: algif_hash(E) af_alg(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) nf_tables(E) s390_trng(E) vfio_ccw(E) mdev(E) vfio_iommu_type1(E) vfio(E) sch_fq_codel(E) drm(E) i2c_core(E) drm_panel_orientation_quirks(E) loop(E) nfnetlink(E) vsock_loopback(E) vmw_vsock_virtio_transport_common(E) vsock(E) ctcm(E) fsm(E) diag288_wdt(E) watchdog(E) zfcp(E) scsi_transport_fc(E) ghash_s390(E) prng(E) aes_s390(E) des_generic(E) des_s390(E) libdes(E) sha3_512_s390(E) sha3_256_s390(E) sha_common(E) paes_s390(E) crypto_engine(E) pkey_cca(E) pkey_ep11(E) zcrypt(E) rng_core(E) pkey_pckmo(E) pkey(E) autofs4(E) [ 308.987439] Unloaded tainted modules: hmac_s390(E):2 [ 308.987650] CPU: 1 UID: 0 PID: 5224 Comm: mempig_verify Kdump: loaded Tainted: G E 6.18.0-gcc-bpf-debug torvalds#431 PREEMPT [ 308.987657] Tainted: [E]=UNSIGNED_MODULE [ 308.987661] Hardware name: IBM 3906 M04 704 (z/VM 7.3.0) [ 308.987666] Krnl PSW : 0404f00180000000 00000349976fa600 (expand+0x240/0x270) [ 308.987676] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3 [ 308.987682] Krnl GPRS: 0000034980000004 0000000000000005 0000000000000030 000003499a0e6d88 [ 308.987688] 0000000000000005 0000034980000005 000002be803ac000 0000023efe6c8300 [ 308.987692] 0000000000000008 0000034998d57290 000002be00000100 0000023e00000008 [ 308.987696] 0000000000000000 0000000000000000 00000349976fa5fc 000002c99b1eb6f0 [ 308.987708] Krnl Code: 00000349976fa5f0: c020008a02f2 larl %r2,000003499883abd4 00000349976fa5f6: c0e5ffe3f4b5 brasl %r14,0000034997378f60 #00000349976fa5fc: af000000 mc 0,0 >00000349976fa600: a7f4ff4c brc 15,00000349976fa498 00000349976fa604: b9040026 lgr %r2,%r6 00000349976fa608: c0300088317f larl %r3,0000034998800906 00000349976fa60e: c0e5fffdb6e1 brasl %r14,00000349976b13d0 00000349976fa614: af000000 mc 0,0 [ 308.987734] Call Trace: [ 308.987738] [<00000349976fa600>] expand+0x240/0x270 [ 308.987744] ([<00000349976fa5fc>] expand+0x23c/0x270) [ 308.987749] [<00000349976ff95e>] rmqueue_bulk+0x71e/0x940 [ 308.987754] [<00000349976ffd7e>] __rmqueue_pcplist+0x1fe/0x2a0 [ 308.987759] [<0000034997700966>] rmqueue.isra.0+0xb46/0xf40 [ 308.987763] [<0000034997703ec8>] get_page_from_freelist+0x198/0x8d0 [ 308.987768] [<0000034997706fa8>] __alloc_frozen_pages_noprof+0x198/0x400 [ 308.987774] [<00000349977536f8>] alloc_pages_mpol+0xb8/0x220 [ 308.987781] [<0000034997753bf6>] folio_alloc_mpol_noprof+0x26/0xc0 [ 308.987786] [<0000034997753e4c>] vma_alloc_folio_noprof+0x6c/0xa0 [ 308.987791] [<0000034997775b22>] vma_alloc_anon_folio_pmd+0x42/0x240 [ 308.987799] [<000003499777bfea>] __do_huge_pmd_anonymous_page+0x3a/0x210 [ 308.987804] [<00000349976cb08e>] __handle_mm_fault+0x4de/0x500 [ 308.987809] [<00000349976cb14c>] handle_mm_fault+0x9c/0x3a0 [ 308.987813] [<000003499734d70e>] do_exception+0x1de/0x540 [ 308.987822] [<0000034998387390>] __do_pgm_check+0x130/0x220 [ 308.987830] [<000003499839a934>] pgm_check_handler+0x114/0x160 [ 308.987838] 3 locks held by mempig_verify/5224: [ 308.987842] #0: 0000023ea44c1e08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0xb2/0x2a0 [ 308.987859] #1: 0000023ee4d41b18 (&pcp->lock){+.+.}-{2:2}, at: rmqueue.isra.0+0xad6/0xf40 [ 308.987871] #2: 0000023efe6c8998 (&zone->lock){..-.}-{2:2}, at: rmqueue_bulk+0x5a/0x940 [ 308.987886] Last Breaking-Event-Address: [ 308.987890] [<0000034997379096>] __warn_printk+0x136/0x140 [ 308.987897] irq event stamp: 52330356 [ 308.987901] hardirqs last enabled at (52330355): [<000003499838742e>] __do_pgm_check+0x1ce/0x220 [ 308.987907] hardirqs last disabled at (52330356): [<000003499839932e>] _raw_spin_lock_irqsave+0x9e/0xe0 [ 308.987913] softirqs last enabled at (52329882): [<0000034997383786>] handle_softirqs+0x2c6/0x530 [ 308.987922] softirqs last disabled at (52329859): [<0000034997382f86>] __irq_exit_rcu+0x126/0x140 [ 308.987929] ---[ end trace 0000000000000000 ]--- [ 308.987936] ------------[ cut here ]------------ [ 308.987940] page type is 0, passed migratetype is 1 (nr=256) [ 308.987951] WARNING: CPU: 1 PID: 5224 at mm/page_alloc.c:860 __del_page_from_free_list+0x1be/0x1e0 [ 308.987960] Modules linked in: algif_hash(E) af_alg(E) nft_fib_inet(E) nft_fib_ipv4(E) nft_fib_ipv6(E) nft_fib(E) nft_reject_inet(E) nf_reject_ipv4(E) nf_reject_ipv6(E) nft_reject(E) nft_ct(E) nft_chain_nat(E) nf_nat(E) nf_conntrack(E) nf_defrag_ipv6(E) nf_defrag_ipv4(E) nf_tables(E) s390_trng(E) vfio_ccw(E) mdev(E) vfio_iommu_type1(E) vfio(E) sch_fq_codel(E) drm(E) i2c_core(E) drm_panel_orientation_quirks(E) loop(E) nfnetlink(E) vsock_loopback(E) vmw_vsock_virtio_transport_common(E) vsock(E) ctcm(E) fsm(E) diag288_wdt(E) watchdog(E) zfcp(E) scsi_transport_fc(E) ghash_s390(E) prng(E) aes_s390(E) des_generic(E) des_s390(E) libdes(E) sha3_512_s390(E) sha3_256_s390(E) sha_common(E) paes_s390(E) crypto_engine(E) pkey_cca(E) pkey_ep11(E) zcrypt(E) rng_core(E) pkey_pckmo(E) pkey(E) autofs4(E) [ 308.988070] Unloaded tainted modules: hmac_s390(E):2 [ 308.988087] CPU: 1 UID: 0 PID: 5224 Comm: mempig_verify Kdump: loaded Tainted: G W E 6.18.0-gcc-bpf-debug torvalds#431 PREEMPT [ 308.988095] Tainted: [W]=WARN, [E]=UNSIGNED_MODULE [ 308.988100] Hardware name: IBM 3906 M04 704 (z/VM 7.3.0) [ 308.988105] Krnl PSW : 0404f00180000000 00000349976f9e32 (__del_page_from_free_list+0x1c2/0x1e0) [ 308.988118] R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:3 PM:0 RI:0 EA:3 [ 308.988127] Krnl GPRS: 0000034980000004 0000000000000005 0000000000000030 000003499a0e6d88 [ 308.988133] 0000000000000005 0000034980000005 0000034998d57290 0000023efe6c8300 [ 308.988139] 0000000000000001 0000000000000008 000002be00000100 000002be803ac000 [ 308.988144] 0000000000000000 0000000000000001 00000349976f9e2e 000002c99b1eb728 [ 308.988153] Krnl Code: 00000349976f9e22: c020008a06d9 larl %r2,000003499883abd4 00000349976f9e28: c0e5ffe3f89c brasl %r14,0000034997378f60 #00000349976f9e2e: af000000 mc 0,0 >00000349976f9e32: a7f4ff4e brc 15,00000349976f9cce 00000349976f9e36: b904002b lgr %r2,%r11 00000349976f9e3a: c030008a06e7 larl %r3,000003499883ac08 00000349976f9e40: c0e5fffdbac8 brasl %r14,00000349976b13d0 00000349976f9e46: af000000 mc 0,0 [ 308.988184] Call Trace: [ 308.988188] [<00000349976f9e32>] __del_page_from_free_list+0x1c2/0x1e0 [ 308.988195] ([<00000349976f9e2e>] __del_page_from_free_list+0x1be/0x1e0) [ 308.988202] [<00000349976ff946>] rmqueue_bulk+0x706/0x940 [ 308.988208] [<00000349976ffd7e>] __rmqueue_pcplist+0x1fe/0x2a0 [ 308.988214] [<0000034997700966>] rmqueue.isra.0+0xb46/0xf40 [ 308.988221] [<0000034997703ec8>] get_page_from_freelist+0x198/0x8d0 [ 308.988227] [<0000034997706fa8>] __alloc_frozen_pages_noprof+0x198/0x400 [ 308.988233] [<00000349977536f8>] alloc_pages_mpol+0xb8/0x220 [ 308.988240] [<0000034997753bf6>] folio_alloc_mpol_noprof+0x26/0xc0 [ 308.988247] [<0000034997753e4c>] vma_alloc_folio_noprof+0x6c/0xa0 [ 308.988253] [<0000034997775b22>] vma_alloc_anon_folio_pmd+0x42/0x240 [ 308.988260] [<000003499777bfea>] __do_huge_pmd_anonymous_page+0x3a/0x210 [ 308.988267] [<00000349976cb08e>] __handle_mm_fault+0x4de/0x500 [ 308.988273] [<00000349976cb14c>] handle_mm_fault+0x9c/0x3a0 [ 308.988279] [<000003499734d70e>] do_exception+0x1de/0x540 [ 308.988286] [<0000034998387390>] __do_pgm_check+0x130/0x220 [ 308.988293] [<000003499839a934>] pgm_check_handler+0x114/0x160 [ 308.988300] 3 locks held by mempig_verify/5224: [ 308.988305] #0: 0000023ea44c1e08 (vm_lock){++++}-{0:0}, at: lock_vma_under_rcu+0xb2/0x2a0 [ 308.988322] #1: 0000023ee4d41b18 (&pcp->lock){+.+.}-{2:2}, at: rmqueue.isra.0+0xad6/0xf40 [ 308.988334] #2: 0000023efe6c8998 (&zone->lock){..-.}-{2:2}, at: rmqueue_bulk+0x5a/0x940 [ 308.988346] Last Breaking-Event-Address: [ 308.988350] [<0000034997379096>] __warn_printk+0x136/0x140 [ 308.988356] irq event stamp: 52330356 [ 308.988360] hardirqs last enabled at (52330355): [<000003499838742e>] __do_pgm_check+0x1ce/0x220 [ 308.988366] hardirqs last disabled at (52330356): [<000003499839932e>] _raw_spin_lock_irqsave+0x9e/0xe0 [ 308.988373] softirqs last enabled at (52329882): [<0000034997383786>] handle_softirqs+0x2c6/0x530 [ 308.988380] softirqs last disabled at (52329859): [<0000034997382f86>] __irq_exit_rcu+0x126/0x140 [ 308.988388] ---[ end trace 0000000000000000 ]--- Link: https://lkml.kernel.org/r/20251215081002.3353900A9c-agordeev@linux.ibm.com Link: https://lkml.kernel.org/r/20251212151457.3898073Add-agordeev@linux.ibm.com Fixes: e6cf9e1 ("mm: page_alloc: fix up block types when merging compatible blocks") Signed-off-by: Alexander Gordeev <agordeev@linux.ibm.com> Reported-by: Marc Hartmayer <mhartmay@linux.ibm.com> Closes: https://lore.kernel.org/linux-mm/87wmalyktd.fsf@linux.ibm.com/ Acked-by: Vlastimil Babka <vbabka@suse.cz> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Reviewed-by: Wei Yang <richard.weiyang@gmail.com> Cc: Marc Hartmayer <mhartmay@linux.ibm.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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A null pointer dereference in handshake_complete() was observed [1]. When handshake_req_next() return NULL in handshake_nl_accept_doit(), function handshake_complete() will be called unexpectedly which triggers this crash. Fix it by goto out_status when req is NULL. [1] Oops: general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI RIP: 0010:handshake_complete+0x36/0x2b0 net/handshake/request.c:288 Call Trace: <TASK> handshake_nl_accept_doit+0x32d/0x7e0 net/handshake/netlink.c:129 genl_family_rcv_msg_doit+0x204/0x300 net/netlink/genetlink.c:1115 genl_family_rcv_msg+0x436/0x670 net/netlink/genetlink.c:1195 genl_rcv_msg+0xcc/0x170 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x14c/0x430 net/netlink/af_netlink.c:2550 genl_rcv+0x2d/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x878/0xb20 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x897/0xd70 net/netlink/af_netlink.c:1894 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa39/0xbf0 net/socket.c:2592 ___sys_sendmsg+0x121/0x1c0 net/socket.c:2646 __sys_sendmsg+0x155/0x200 net/socket.c:2678 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x5f/0x350 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x76/0x7e </TASK> Fixes: fe67b06 ("net/handshake: convert handshake_nl_accept_doit() to FD_PREPARE()") Reviewed-by: Chuck Lever <chuck.lever@oracle.com> Reported-by: Dan Carpenter <dan.carpenter@linaro.org> Closes: https://lore.kernel.org/kernel-tls-handshake/aScekpuOYHRM9uOd@morisot.1015granger.net/T/#m7cfa5c11efc626d77622b2981591197a2acdd65e Signed-off-by: Wang Liang <wangliang74@huawei.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20251212012723.4111831-1-wangliang74@huawei.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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…nged() There has been a syzkaller bug reported recently with the following trace: list_del corruption, ffff888058bea080->prev is LIST_POISON2 (dead000000000122) ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:59! Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI CPU: 3 UID: 0 PID: 21246 Comm: syz.0.2928 Not tainted syzkaller #0 PREEMPT(full) Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 RIP: 0010:__list_del_entry_valid_or_report+0x13e/0x200 lib/list_debug.c:59 Code: 48 c7 c7 e0 71 f0 8b e8 30 08 ef fc 90 0f 0b 48 89 ef e8 a5 02 55 fd 48 89 ea 48 89 de 48 c7 c7 40 72 f0 8b e8 13 08 ef fc 90 <0f> 0b 48 89 ef e8 88 02 55 fd 48 89 ea 48 b8 00 00 00 00 00 fc ff RSP: 0018:ffffc9000d49f370 EFLAGS: 00010286 RAX: 000000000000004e RBX: ffff888058bea080 RCX: ffffc9002817d000 RDX: 0000000000000000 RSI: ffffffff819becc6 RDI: 0000000000000005 RBP: dead000000000122 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000080000000 R11: 0000000000000001 R12: ffff888039e9c230 R13: ffff888058bea088 R14: ffff888058bea080 R15: ffff888055461480 FS: 00007fbbcfe6f6c0(0000) GS:ffff8880d6d0a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c3afcb0 CR3: 00000000382c7000 CR4: 0000000000352ef0 Call Trace: <TASK> __list_del_entry_valid include/linux/list.h:132 [inline] __list_del_entry include/linux/list.h:223 [inline] list_del_rcu include/linux/rculist.h:178 [inline] __team_queue_override_port_del drivers/net/team/team_core.c:826 [inline] __team_queue_override_port_del drivers/net/team/team_core.c:821 [inline] team_queue_override_port_prio_changed drivers/net/team/team_core.c:883 [inline] team_priority_option_set+0x171/0x2f0 drivers/net/team/team_core.c:1534 team_option_set drivers/net/team/team_core.c:376 [inline] team_nl_options_set_doit+0x8ae/0xe60 drivers/net/team/team_core.c:2653 genl_family_rcv_msg_doit+0x209/0x2f0 net/netlink/genetlink.c:1115 genl_family_rcv_msg net/netlink/genetlink.c:1195 [inline] genl_rcv_msg+0x55c/0x800 net/netlink/genetlink.c:1210 netlink_rcv_skb+0x158/0x420 net/netlink/af_netlink.c:2552 genl_rcv+0x28/0x40 net/netlink/genetlink.c:1219 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline] netlink_unicast+0x5aa/0x870 net/netlink/af_netlink.c:1346 netlink_sendmsg+0x8c8/0xdd0 net/netlink/af_netlink.c:1896 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmsg+0x16d/0x220 net/socket.c:2716 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The problem is in this flow: 1) Port is enabled, queue_id != 0, in qom_list 2) Port gets disabled -> team_port_disable() -> team_queue_override_port_del() -> del (removed from list) 3) Port is disabled, queue_id != 0, not in any list 4) Priority changes -> team_queue_override_port_prio_changed() -> checks: port disabled && queue_id != 0 -> calls del - hits the BUG as it is removed already To fix this, change the check in team_queue_override_port_prio_changed() so it returns early if port is not enabled. Reported-by: syzbot+422806e5f4cce722a71f@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=422806e5f4cce722a71f Fixes: 6c31ff3 ("team: remove synchronize_rcu() called during queue override change") Signed-off-by: Jiri Pirko <jiri@nvidia.com> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20251212102953.167287-1-jiri@resnulli.us Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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After the blamed commit below, if the MPC subflow is already in TCP_CLOSE status or has fallback to TCP at mptcp_disconnect() time, mptcp_do_fastclose() skips setting the `send_fastclose flag` and the later __mptcp_close_ssk() does not reset anymore the related subflow context. Any later connection will be created with both the `request_mptcp` flag and the msk-level fallback status off (it is unconditionally cleared at MPTCP disconnect time), leading to a warning in subflow_data_ready(): WARNING: CPU: 26 PID: 8996 at net/mptcp/subflow.c:1519 subflow_data_ready (net/mptcp/subflow.c:1519 (discriminator 13)) Modules linked in: CPU: 26 UID: 0 PID: 8996 Comm: syz.22.39 Not tainted 6.18.0-rc7-05427-g11fc074f6c36 #1 PREEMPT(voluntary) Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011 RIP: 0010:subflow_data_ready (net/mptcp/subflow.c:1519 (discriminator 13)) Code: 90 0f 0b 90 90 e9 04 fe ff ff e8 b7 1e f5 fe 89 ee bf 07 00 00 00 e8 db 19 f5 fe 83 fd 07 0f 84 35 ff ff ff e8 9d 1e f5 fe 90 <0f> 0b 90 e9 27 ff ff ff e8 8f 1e f5 fe 4c 89 e7 48 89 de e8 14 09 RSP: 0018:ffffc9002646fb30 EFLAGS: 00010293 RAX: 0000000000000000 RBX: ffff88813b218000 RCX: ffffffff825c8435 RDX: ffff8881300b3580 RSI: ffffffff825c8443 RDI: 0000000000000005 RBP: 000000000000000b R08: ffffffff825c8435 R09: 000000000000000b R10: 0000000000000005 R11: 0000000000000007 R12: ffff888131ac0000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f88330af6c0(0000) GS:ffff888a93dd2000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f88330aefe8 CR3: 000000010ff59000 CR4: 0000000000350ef0 Call Trace: <TASK> tcp_data_ready (net/ipv4/tcp_input.c:5356) tcp_data_queue (net/ipv4/tcp_input.c:5445) tcp_rcv_state_process (net/ipv4/tcp_input.c:7165) tcp_v4_do_rcv (net/ipv4/tcp_ipv4.c:1955) __release_sock (include/net/sock.h:1158 (discriminator 6) net/core/sock.c:3180 (discriminator 6)) release_sock (net/core/sock.c:3737) mptcp_sendmsg (net/mptcp/protocol.c:1763 net/mptcp/protocol.c:1857) inet_sendmsg (net/ipv4/af_inet.c:853 (discriminator 7)) __sys_sendto (net/socket.c:727 (discriminator 15) net/socket.c:742 (discriminator 15) net/socket.c:2244 (discriminator 15)) __x64_sys_sendto (net/socket.c:2247) do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:130) RIP: 0033:0x7f883326702d Address the issue setting an explicit `fastclosing` flag at fastclose time, and checking such flag after mptcp_do_fastclose(). Fixes: ae15506 ("mptcp: fix duplicate reset on fastclose") Cc: stable@vger.kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20251212-net-mptcp-subflow_data_ready-warn-v1-2-d1f9fd1c36c8@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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In e1000_tbi_should_accept() we read the last byte of the frame via 'data[length - 1]' to evaluate the TBI workaround. If the descriptor- reported length is zero or larger than the actual RX buffer size, this read goes out of bounds and can hit unrelated slab objects. The issue is observed from the NAPI receive path (e1000_clean_rx_irq): ================================================================== BUG: KASAN: slab-out-of-bounds in e1000_tbi_should_accept+0x610/0x790 Read of size 1 at addr ffff888014114e54 by task sshd/363 CPU: 0 PID: 363 Comm: sshd Not tainted 5.18.0-rc1 #1 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.0-59-gc9ba5276e321-prebuilt.qemu.org 04/01/2014 Call Trace: <IRQ> dump_stack_lvl+0x5a/0x74 print_address_description+0x7b/0x440 print_report+0x101/0x200 kasan_report+0xc1/0xf0 e1000_tbi_should_accept+0x610/0x790 e1000_clean_rx_irq+0xa8c/0x1110 e1000_clean+0xde2/0x3c10 __napi_poll+0x98/0x380 net_rx_action+0x491/0xa20 __do_softirq+0x2c9/0x61d do_softirq+0xd1/0x120 </IRQ> <TASK> __local_bh_enable_ip+0xfe/0x130 ip_finish_output2+0x7d5/0xb00 __ip_queue_xmit+0xe24/0x1ab0 __tcp_transmit_skb+0x1bcb/0x3340 tcp_write_xmit+0x175d/0x6bd0 __tcp_push_pending_frames+0x7b/0x280 tcp_sendmsg_locked+0x2e4f/0x32d0 tcp_sendmsg+0x24/0x40 sock_write_iter+0x322/0x430 vfs_write+0x56c/0xa60 ksys_write+0xd1/0x190 do_syscall_64+0x43/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f511b476b10 Code: 73 01 c3 48 8b 0d 88 d3 2b 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d f9 2b 2c 00 00 75 10 b8 01 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 8e 9b 01 00 48 89 04 24 RSP: 002b:00007ffc9211d4e8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000004024 RCX: 00007f511b476b10 RDX: 0000000000004024 RSI: 0000559a9385962c RDI: 0000000000000003 RBP: 0000559a9383a400 R08: fffffffffffffff0 R09: 0000000000004f00 R10: 0000000000000070 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc9211d57f R14: 0000559a9347bde7 R15: 0000000000000003 </TASK> Allocated by task 1: __kasan_krealloc+0x131/0x1c0 krealloc+0x90/0xc0 add_sysfs_param+0xcb/0x8a0 kernel_add_sysfs_param+0x81/0xd4 param_sysfs_builtin+0x138/0x1a6 param_sysfs_init+0x57/0x5b do_one_initcall+0x104/0x250 do_initcall_level+0x102/0x132 do_initcalls+0x46/0x74 kernel_init_freeable+0x28f/0x393 kernel_init+0x14/0x1a0 ret_from_fork+0x22/0x30 The buggy address belongs to the object at ffff888014114000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 1620 bytes to the right of 2048-byte region [ffff888014114000, ffff888014114800] The buggy address belongs to the physical page: page:ffffea0000504400 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x14110 head:ffffea0000504400 order:3 compound_mapcount:0 compound_pincount:0 flags: 0x100000000010200(slab|head|node=0|zone=1) raw: 0100000000010200 0000000000000000 dead000000000001 ffff888013442000 raw: 0000000000000000 0000000000080008 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected ================================================================== This happens because the TBI check unconditionally dereferences the last byte without validating the reported length first: u8 last_byte = *(data + length - 1); Fix by rejecting the frame early if the length is zero, or if it exceeds adapter->rx_buffer_len. This preserves the TBI workaround semantics for valid frames and prevents touching memory beyond the RX buffer. Fixes: 2037110 ("e1000: move tbi workaround code into helper function") Cc: stable@vger.kernel.org Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com> Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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When mana_serv_reset() encounters -ETIMEDOUT or -EPROTO from mana_gd_resume(), it performs a PCI rescan via mana_serv_rescan(). mana_serv_rescan() calls pci_stop_and_remove_bus_device(), which can invoke the driver's remove path and free the gdma_context associated with the device. After returning, mana_serv_reset() currently jumps to the out label and attempts to clear gc->in_service, dereferencing a freed gdma_context. The issue was observed with the following call logs: [ 698.942636] BUG: unable to handle page fault for address: ff6c2b638088508d [ 698.943121] #PF: supervisor write access in kernel mode [ 698.943423] #PF: error_code(0x0002) - not-present page [S[ 698.943793] Pat Dec 6 07:GD5 100000067 P4D 1002f7067 PUD 1002f8067 PMD 101bef067 PTE 0 0:56 2025] hv_[n e 698.944283] Oops: Oops: 0002 [#1] SMP NOPTI tvsc f8615163-00[ 698.944611] CPU: 28 UID: 0 PID: 249 Comm: kworker/28:1 ... [Sat Dec 6 07:50:56 2025] R10: [ 699.121594] mana 7870:00:00.0 enP30832s1: Configured vPort 0 PD 18 DB 16 000000000000001b R11: 0000000000000000 R12: ff44cf3f40270000 [Sat Dec 6 07:50:56 2025] R13: 0000000000000001 R14: ff44cf3f402700c8 R15: ff44cf3f4021b405 [Sat Dec 6 07:50:56 2025] FS: 0000000000000000(0000) GS:ff44cf7e9fcf9000(0000) knlGS:0000000000000000 [Sat Dec 6 07:50:56 2025] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [Sat Dec 6 07:50:56 2025] CR2: ff6c2b638088508d CR3: 000000011fe43001 CR4: 0000000000b73ef0 [Sat Dec 6 07:50:56 2025] Call Trace: [Sat Dec 6 07:50:56 2025] <TASK> [Sat Dec 6 07:50:56 2025] mana_serv_func+0x24/0x50 [mana] [Sat Dec 6 07:50:56 2025] process_one_work+0x190/0x350 [Sat Dec 6 07:50:56 2025] worker_thread+0x2b7/0x3d0 [Sat Dec 6 07:50:56 2025] kthread+0xf3/0x200 [Sat Dec 6 07:50:56 2025] ? __pfx_worker_thread+0x10/0x10 [Sat Dec 6 07:50:56 2025] ? __pfx_kthread+0x10/0x10 [Sat Dec 6 07:50:56 2025] ret_from_fork+0x21a/0x250 [Sat Dec 6 07:50:56 2025] ? __pfx_kthread+0x10/0x10 [Sat Dec 6 07:50:56 2025] ret_from_fork_asm+0x1a/0x30 [Sat Dec 6 07:50:56 2025] </TASK> Fix this by returning immediately after mana_serv_rescan() to avoid accessing GC state that may no longer be valid. Fixes: 9bf6603 ("net: mana: Handle hardware recovery events when probing the device") Reviewed-by: Simon Horman <horms@kernel.org> Reviewed-by: Long Li <longli@microsoft.com> Signed-off-by: Dipayaan Roy <dipayanroy@linux.microsoft.com> Link: https://patch.msgid.link/20251218131054.GA3173@linuxonhyperv3.guj3yctzbm1etfxqx2vob5hsef.xx.internal.cloudapp.net Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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There is a crash issue when running zero copy XDP_TX action, the crash log is shown below. [ 216.122464] Unable to handle kernel paging request at virtual address fffeffff80000000 [ 216.187524] Internal error: Oops: 0000000096000144 [#1] SMP [ 216.301694] Call trace: [ 216.304130] dcache_clean_poc+0x20/0x38 (P) [ 216.308308] __dma_sync_single_for_device+0x1bc/0x1e0 [ 216.313351] stmmac_xdp_xmit_xdpf+0x354/0x400 [ 216.317701] __stmmac_xdp_run_prog+0x164/0x368 [ 216.322139] stmmac_napi_poll_rxtx+0xba8/0xf00 [ 216.326576] __napi_poll+0x40/0x218 [ 216.408054] Kernel panic - not syncing: Oops: Fatal exception in interrupt For XDP_TX action, the xdp_buff is converted to xdp_frame by xdp_convert_buff_to_frame(). The memory type of the resulting xdp_frame depends on the memory type of the xdp_buff. For page pool based xdp_buff it produces xdp_frame with memory type MEM_TYPE_PAGE_POOL. For zero copy XSK pool based xdp_buff it produces xdp_frame with memory type MEM_TYPE_PAGE_ORDER0. However, stmmac_xdp_xmit_back() does not check the memory type and always uses the page pool type, this leads to invalid mappings and causes the crash. Therefore, check the xdp_buff memory type in stmmac_xdp_xmit_back() to fix this issue. Fixes: bba2556 ("net: stmmac: Enable RX via AF_XDP zero-copy") Signed-off-by: Wei Fang <wei.fang@nxp.com> Reviewed-by: Hariprasad Kelam <hkelam@marvell.com> Link: https://patch.msgid.link/20251204071332.1907111-1-wei.fang@nxp.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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syzbot reported a crash [1] in dql_completed() after recent usbnet BQL adoption. The reason for the crash is that netdev_reset_queue() is called too soon. It should be called after cancel_work_sync(&dev->bh_work) to make sure no more TX completion can happen. [1] kernel BUG at lib/dynamic_queue_limits.c:99 ! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 5197 Comm: udevd Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:dql_completed+0xbe1/0xbf0 lib/dynamic_queue_limits.c:99 Call Trace: <IRQ> netdev_tx_completed_queue include/linux/netdevice.h:3864 [inline] netdev_completed_queue include/linux/netdevice.h:3894 [inline] usbnet_bh+0x793/0x1020 drivers/net/usb/usbnet.c:1601 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 bh_worker+0x2b1/0x600 kernel/workqueue.c:3611 tasklet_action+0xc/0x70 kernel/softirq.c:952 handle_softirqs+0x27d/0x850 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 Fixes: 7ff14c5 ("usbnet: Add support for Byte Queue Limits (BQL)") Reported-by: syzbot+5b55e49f8bbd84631a9c@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/6945644f.a70a0220.207337.0113.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Simon Schippers <simon.schippers@tu-dortmund.de> Link: https://patch.msgid.link/20251219144459.692715-1-edumazet@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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… to macb_open() In the non-RT kernel, local_bh_disable() merely disables preemption, whereas it maps to an actual spin lock in the RT kernel. Consequently, when attempting to refill RX buffers via netdev_alloc_skb() in macb_mac_link_up(), a deadlock scenario arises as follows: WARNING: possible circular locking dependency detected 6.18.0-08691-g2061f18ad76e torvalds#39 Not tainted ------------------------------------------------------ kworker/0:0/8 is trying to acquire lock: ffff00080369bbe0 (&bp->lock){+.+.}-{3:3}, at: macb_start_xmit+0x808/0xb7c but task is already holding lock: ffff000803698e58 (&queue->tx_ptr_lock){+...}-{3:3}, at: macb_start_xmit +0x148/0xb7c which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&queue->tx_ptr_lock){+...}-{3:3}: rt_spin_lock+0x50/0x1f0 macb_start_xmit+0x148/0xb7c dev_hard_start_xmit+0x94/0x284 sch_direct_xmit+0x8c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 -> #2 (_xmit_ETHER#2){+...}-{3:3}: rt_spin_lock+0x50/0x1f0 sch_direct_xmit+0x11c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 -> #1 ((softirq_ctrl.lock)){+.+.}-{3:3}: lock_release+0x250/0x348 __local_bh_enable_ip+0x7c/0x240 __netdev_alloc_skb+0x1b4/0x1d8 gem_rx_refill+0xdc/0x240 gem_init_rings+0xb4/0x108 macb_mac_link_up+0x9c/0x2b4 phylink_resolve+0x170/0x614 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 -> #0 (&bp->lock){+.+.}-{3:3}: __lock_acquire+0x15a8/0x2084 lock_acquire+0x1cc/0x350 rt_spin_lock+0x50/0x1f0 macb_start_xmit+0x808/0xb7c dev_hard_start_xmit+0x94/0x284 sch_direct_xmit+0x8c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 other info that might help us debug this: Chain exists of: &bp->lock --> _xmit_ETHER#2 --> &queue->tx_ptr_lock Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&queue->tx_ptr_lock); lock(_xmit_ETHER#2); lock(&queue->tx_ptr_lock); lock(&bp->lock); *** DEADLOCK *** Call trace: show_stack+0x18/0x24 (C) dump_stack_lvl+0xa0/0xf0 dump_stack+0x18/0x24 print_circular_bug+0x28c/0x370 check_noncircular+0x198/0x1ac __lock_acquire+0x15a8/0x2084 lock_acquire+0x1cc/0x350 rt_spin_lock+0x50/0x1f0 macb_start_xmit+0x808/0xb7c dev_hard_start_xmit+0x94/0x284 sch_direct_xmit+0x8c/0x37c __dev_queue_xmit+0x708/0x1120 neigh_resolve_output+0x148/0x28c ip6_finish_output2+0x2c0/0xb2c __ip6_finish_output+0x114/0x308 ip6_output+0xc4/0x4a4 mld_sendpack+0x220/0x68c mld_ifc_work+0x2a8/0x4f4 process_one_work+0x20c/0x5f8 worker_thread+0x1b0/0x35c kthread+0x144/0x200 ret_from_fork+0x10/0x20 Notably, invoking the mog_init_rings() callback upon link establishment is unnecessary. Instead, we can exclusively call mog_init_rings() within the ndo_open() callback. This adjustment resolves the deadlock issue. Furthermore, since MACB_CAPS_MACB_IS_EMAC cases do not use mog_init_rings() when opening the network interface via at91ether_open(), moving mog_init_rings() to macb_open() also eliminates the MACB_CAPS_MACB_IS_EMAC check. Fixes: 633e98a ("net: macb: use resolved link config in mac_link_up()") Cc: stable@vger.kernel.org Suggested-by: Kevin Hao <kexin.hao@windriver.com> Signed-off-by: Xiaolei Wang <xiaolei.wang@windriver.com> Link: https://patch.msgid.link/20251222015624.1994551-1-xiaolei.wang@windriver.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
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This reverts commit f804a58. This change introduced the following panic, and mt792x_load_firmware() fails. wifi is dead on systems with mt792x wireless. kern :crit : kernel BUG at lib/string_helpers.c:1043! kern :warn : Oops: invalid opcode: 0000 [#1] SMP NOPTI kern :warn : CPU: 14 UID: 0 PID: 61 Comm: kworker/14:0 Tainted: G W 6.19.0-rc1 #1 PREEMPT(voluntary) kern :warn : Tainted: [W]=WARN kern :warn : Hardware name: Framework Laptop 13 (AMD Ryzen 7040Series)/FRANMDCP07, BIOS 03.16 07/25/2025 kern :warn : Workqueue: events mt7921_init_work [mt7921_common] kern :warn : RIP: 0010:__fortify_panic+0xd/0xf kern :warn : Code: 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 40 0f b6 ff e8 c3 55 71 00 <0f> 0b 48 8b 54 24 10 48 8b 74 24 08 4c 89 e9 48 c7 c7 00 a2 d5 a0 kern :warn : RSP: 0018:ffffa7a5c03a3d10 EFLAGS: 00010246 kern :warn : RAX: ffffffffa0d7aaf2 RBX: 0000000000000000 RCX: ffffffffa0d7aaf2 kern :warn : RDX: 0000000000000011 RSI: ffffffffa0d5a170 RDI: ffffffffa128db10 kern :warn : RBP: ffff91650ae52060 R08: 0000000000000010 R09: ffffa7a5c31b2000 kern :warn : R10: ffffa7a5c03a3bf0 R11: 00000000ffffffff R12: 0000000000000000 kern :warn : R13: ffffa7a5c31b2000 R14: 0000000000001000 R15: 0000000000000000 kern :warn : FS: 0000000000000000(0000) GS:ffff91743e664000(0000) knlGS:0000000000000000 kern :warn : CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 kern :warn : CR2: 00007f10786c241c CR3: 00000003eca24000 CR4: 0000000000f50ef0 kern :warn : PKRU: 55555554 kern :warn : Call Trace: kern :warn : <TASK> kern :warn : mt76_connac2_load_patch.cold+0x2b/0xa41 [mt76_connac_lib] kern :warn : ? srso_alias_return_thunk+0x5/0xfbef5 kern :warn : mt792x_load_firmware+0x36/0x150 [mt792x_lib] kern :warn : mt7921_run_firmware+0x2c/0x4a0 [mt7921_common] kern :warn : ? srso_alias_return_thunk+0x5/0xfbef5 kern :warn : ? mt7921_rr+0x12/0x30 [mt7921e] kern :warn : ? srso_alias_return_thunk+0x5/0xfbef5 kern :warn : ? ____mt76_poll_msec+0x75/0xb0 [mt76] kern :warn : mt7921e_mcu_init+0x4c/0x7a [mt7921e] kern :warn : mt7921_init_work+0x51/0x190 [mt7921_common] kern :warn : process_one_work+0x18b/0x340 kern :warn : worker_thread+0x256/0x3a0 kern :warn : ? __pfx_worker_thread+0x10/0x10 kern :warn : kthread+0xfc/0x240 kern :warn : ? __pfx_kthread+0x10/0x10 kern :warn : ? __pfx_kthread+0x10/0x10 kern :warn : ret_from_fork+0x254/0x290 kern :warn : ? __pfx_kthread+0x10/0x10 kern :warn : ret_from_fork_asm+0x1a/0x30 kern :warn : </TASK> Signed-off-by: Shuah Khan <skhan@linuxfoundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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ctx->tcxt_list holds the tasks using this ring, and it's currently
protected by the normal ctx->uring_lock. However, this can cause a
circular locking issue, as reported by syzbot, where cancelations off
exec end up needing to remove an entry from this list:
======================================================
WARNING: possible circular locking dependency detected
syzkaller #0 Tainted: G L
------------------------------------------------------
syz.0.9999/12287 is trying to acquire lock:
ffff88805851c0a8 (&ctx->uring_lock){+.+.}-{4:4}, at: io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
but task is already holding lock:
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&sig->cred_guard_mutex){+.+.}-{4:4}:
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
proc_pid_attr_write+0x547/0x630 fs/proc/base.c:2837
vfs_write+0x27e/0xb30 fs/read_write.c:684
ksys_write+0x145/0x250 fs/read_write.c:738
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #1 (sb_writers#3){.+.+}-{0:0}:
percpu_down_read_internal include/linux/percpu-rwsem.h:53 [inline]
percpu_down_read_freezable include/linux/percpu-rwsem.h:83 [inline]
__sb_start_write include/linux/fs/super.h:19 [inline]
sb_start_write+0x4d/0x1c0 include/linux/fs/super.h:125
mnt_want_write+0x41/0x90 fs/namespace.c:499
open_last_lookups fs/namei.c:4529 [inline]
path_openat+0xadd/0x3dd0 fs/namei.c:4784
do_filp_open+0x1fa/0x410 fs/namei.c:4814
io_openat2+0x3e0/0x5c0 io_uring/openclose.c:143
__io_issue_sqe+0x181/0x4b0 io_uring/io_uring.c:1792
io_issue_sqe+0x165/0x1060 io_uring/io_uring.c:1815
io_queue_sqe io_uring/io_uring.c:2042 [inline]
io_submit_sqe io_uring/io_uring.c:2320 [inline]
io_submit_sqes+0xbf4/0x2140 io_uring/io_uring.c:2434
__do_sys_io_uring_enter io_uring/io_uring.c:3280 [inline]
__se_sys_io_uring_enter+0x2e0/0x2b60 io_uring/io_uring.c:3219
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
-> #0 (&ctx->uring_lock){+.+.}-{4:4}:
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
other info that might help us debug this:
Chain exists of:
&ctx->uring_lock --> sb_writers#3 --> &sig->cred_guard_mutex
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&sig->cred_guard_mutex);
lock(sb_writers#3);
lock(&sig->cred_guard_mutex);
lock(&ctx->uring_lock);
*** DEADLOCK ***
1 lock held by syz.0.9999/12287:
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: prepare_bprm_creds fs/exec.c:1360 [inline]
#0: ffff88802db5a2e0 (&sig->cred_guard_mutex){+.+.}-{4:4}, at: bprm_execve+0xb9/0x1400 fs/exec.c:1733
stack backtrace:
CPU: 0 UID: 0 PID: 12287 Comm: syz.0.9999 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
<TASK>
dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
print_circular_bug+0x2e2/0x300 kernel/locking/lockdep.c:2043
check_noncircular+0x12e/0x150 kernel/locking/lockdep.c:2175
check_prev_add kernel/locking/lockdep.c:3165 [inline]
check_prevs_add kernel/locking/lockdep.c:3284 [inline]
validate_chain kernel/locking/lockdep.c:3908 [inline]
__lock_acquire+0x15a6/0x2cf0 kernel/locking/lockdep.c:5237
lock_acquire+0x107/0x340 kernel/locking/lockdep.c:5868
__mutex_lock_common kernel/locking/mutex.c:614 [inline]
__mutex_lock+0x187/0x1350 kernel/locking/mutex.c:776
io_uring_del_tctx_node+0xf0/0x2c0 io_uring/tctx.c:179
io_uring_clean_tctx+0xd4/0x1a0 io_uring/tctx.c:195
io_uring_cancel_generic+0x6ca/0x7d0 io_uring/cancel.c:646
io_uring_task_cancel include/linux/io_uring.h:24 [inline]
begin_new_exec+0x10ed/0x2440 fs/exec.c:1131
load_elf_binary+0x9f8/0x2d70 fs/binfmt_elf.c:1010
search_binary_handler fs/exec.c:1669 [inline]
exec_binprm fs/exec.c:1701 [inline]
bprm_execve+0x92e/0x1400 fs/exec.c:1753
do_execveat_common+0x510/0x6a0 fs/exec.c:1859
do_execve fs/exec.c:1933 [inline]
__do_sys_execve fs/exec.c:2009 [inline]
__se_sys_execve fs/exec.c:2004 [inline]
__x64_sys_execve+0x94/0xb0 fs/exec.c:2004
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xec/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff3a8b8f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ff3a9a97038 EFLAGS: 00000246 ORIG_RAX: 000000000000003b
RAX: ffffffffffffffda RBX: 00007ff3a8de5fa0 RCX: 00007ff3a8b8f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000400
RBP: 00007ff3a8c13f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007ff3a8de6038 R14: 00007ff3a8de5fa0 R15: 00007ff3a8f0fa28
</TASK>
Add a separate lock just for the tctx_list, tctx_lock. This can nest
under ->uring_lock, where necessary, and be used separately for list
manipulation. For the cancelation off exec side, this removes the
need to grab ->uring_lock, hence fixing the circular locking
dependency.
Reported-by: syzbot+b0e3b77ffaa8a4067ce5@syzkaller.appspotmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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irdma_net_event() should not dereference anything from "neigh" (alias "ptr") until it has checked that the event is NETEVENT_NEIGH_UPDATE. Other events come with different structures pointed to by "ptr" and they may be smaller than struct neighbour. Move the read of neigh->dev under the NETEVENT_NEIGH_UPDATE case. The bug is mostly harmless, but it triggers KASAN on debug kernels: BUG: KASAN: stack-out-of-bounds in irdma_net_event+0x32e/0x3b0 [irdma] Read of size 8 at addr ffffc900075e07f0 by task kworker/27:2/542554 CPU: 27 PID: 542554 Comm: kworker/27:2 Kdump: loaded Not tainted 5.14.0-630.el9.x86_64+debug #1 Hardware name: [...] Workqueue: events rt6_probe_deferred Call Trace: <IRQ> dump_stack_lvl+0x60/0xb0 print_address_description.constprop.0+0x2c/0x3f0 print_report+0xb4/0x270 kasan_report+0x92/0xc0 irdma_net_event+0x32e/0x3b0 [irdma] notifier_call_chain+0x9e/0x180 atomic_notifier_call_chain+0x5c/0x110 rt6_do_redirect+0xb91/0x1080 tcp_v6_err+0xe9b/0x13e0 icmpv6_notify+0x2b2/0x630 ndisc_redirect_rcv+0x328/0x530 icmpv6_rcv+0xc16/0x1360 ip6_protocol_deliver_rcu+0xb84/0x12e0 ip6_input_finish+0x117/0x240 ip6_input+0xc4/0x370 ipv6_rcv+0x420/0x7d0 __netif_receive_skb_one_core+0x118/0x1b0 process_backlog+0xd1/0x5d0 __napi_poll.constprop.0+0xa3/0x440 net_rx_action+0x78a/0xba0 handle_softirqs+0x2d4/0x9c0 do_softirq+0xad/0xe0 </IRQ> Fixes: 915cc7a ("RDMA/irdma: Add miscellaneous utility definitions") Link: https://patch.msgid.link/r/20251127143150.121099-1-mschmidt@redhat.com Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
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skbuff_fclone_cache was created without defining a usercopy region, [1] unlike skbuff_head_cache which properly whitelists the cb[] field. [2] This causes a usercopy BUG() when CONFIG_HARDENED_USERCOPY is enabled and the kernel attempts to copy sk_buff.cb data to userspace via sock_recv_errqueue() -> put_cmsg(). The crash occurs when: 1. TCP allocates an skb using alloc_skb_fclone() (from skbuff_fclone_cache) [1] 2. The skb is cloned via skb_clone() using the pre-allocated fclone [3] 3. The cloned skb is queued to sk_error_queue for timestamp reporting 4. Userspace reads the error queue via recvmsg(MSG_ERRQUEUE) 5. sock_recv_errqueue() calls put_cmsg() to copy serr->ee from skb->cb [4] 6. __check_heap_object() fails because skbuff_fclone_cache has no usercopy whitelist [5] When cloned skbs allocated from skbuff_fclone_cache are used in the socket error queue, accessing the sock_exterr_skb structure in skb->cb via put_cmsg() triggers a usercopy hardening violation: [ 5.379589] usercopy: Kernel memory exposure attempt detected from SLUB object 'skbuff_fclone_cache' (offset 296, size 16)! [ 5.382796] kernel BUG at mm/usercopy.c:102! [ 5.383923] Oops: invalid opcode: 0000 [#1] SMP KASAN NOPTI [ 5.384903] CPU: 1 UID: 0 PID: 138 Comm: poc_put_cmsg Not tainted 6.12.57 torvalds#7 [ 5.384903] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.16.3-0-ga6ed6b701f0a-prebuilt.qemu.org 04/01/2014 [ 5.384903] RIP: 0010:usercopy_abort+0x6c/0x80 [ 5.384903] Code: 1a 86 51 48 c7 c2 40 15 1a 86 41 52 48 c7 c7 c0 15 1a 86 48 0f 45 d6 48 c7 c6 80 15 1a 86 48 89 c1 49 0f 45 f3 e8 84 27 88 ff <0f> 0b 490 [ 5.384903] RSP: 0018:ffffc900006f77a8 EFLAGS: 00010246 [ 5.384903] RAX: 000000000000006f RBX: ffff88800f0ad2a8 RCX: 1ffffffff0f72e74 [ 5.384903] RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff87b973a0 [ 5.384903] RBP: 0000000000000010 R08: 0000000000000000 R09: fffffbfff0f72e74 [ 5.384903] R10: 0000000000000003 R11: 79706f6372657375 R12: 0000000000000001 [ 5.384903] R13: ffff88800f0ad2b8 R14: ffffea00003c2b40 R15: ffffea00003c2b00 [ 5.384903] FS: 0000000011bc4380(0000) GS:ffff8880bf100000(0000) knlGS:0000000000000000 [ 5.384903] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 5.384903] CR2: 000056aa3b8e5fe4 CR3: 000000000ea26004 CR4: 0000000000770ef0 [ 5.384903] PKRU: 55555554 [ 5.384903] Call Trace: [ 5.384903] <TASK> [ 5.384903] __check_heap_object+0x9a/0xd0 [ 5.384903] __check_object_size+0x46c/0x690 [ 5.384903] put_cmsg+0x129/0x5e0 [ 5.384903] sock_recv_errqueue+0x22f/0x380 [ 5.384903] tls_sw_recvmsg+0x7ed/0x1960 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5.384903] ? schedule+0x6d/0x270 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 [ 5.384903] ? mutex_unlock+0x81/0xd0 [ 5.384903] ? __pfx_mutex_unlock+0x10/0x10 [ 5.384903] ? __pfx_tls_sw_recvmsg+0x10/0x10 [ 5.384903] ? _raw_spin_lock_irqsave+0x8f/0xf0 [ 5.384903] ? _raw_read_unlock_irqrestore+0x20/0x40 [ 5.384903] ? srso_alias_return_thunk+0x5/0xfbef5 The crash offset 296 corresponds to skb2->cb within skbuff_fclones: - sizeof(struct sk_buff) = 232 - offsetof(struct sk_buff, cb) = 40 - offset of skb2.cb in fclones = 232 + 40 = 272 - crash offset 296 = 272 + 24 (inside sock_exterr_skb.ee) This patch uses a local stack variable as a bounce buffer to avoid the hardened usercopy check failure. [1] https://elixir.bootlin.com/linux/v6.12.62/source/net/ipv4/tcp.c#L885 [2] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5104 [3] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5566 [4] https://elixir.bootlin.com/linux/v6.12.62/source/net/core/skbuff.c#L5491 [5] https://elixir.bootlin.com/linux/v6.12.62/source/mm/slub.c#L5719 Fixes: 6d07d1c ("usercopy: Restrict non-usercopy caches to size 0") Reported-by: Xiang Mei <xmei5@asu.edu> Signed-off-by: Weiming Shi <bestswngs@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20251223203534.1392218-2-bestswngs@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Fix assert lock warning while calling devl_param_driverinit_value_set() in ena. WARNING: net/devlink/core.c:261 at devl_assert_locked+0x62/0x90, CPU#0: kworker/0:0/9 CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.19.0-rc2+ #1 PREEMPT(lazy) Hardware name: Amazon EC2 m8i-flex.4xlarge/, BIOS 1.0 10/16/2017 Workqueue: events work_for_cpu_fn RIP: 0010:devl_assert_locked+0x62/0x90 Call Trace: <TASK> devl_param_driverinit_value_set+0x15/0x1c0 ena_devlink_alloc+0x18c/0x220 [ena] ? __pfx_ena_devlink_alloc+0x10/0x10 [ena] ? trace_hardirqs_on+0x18/0x140 ? lockdep_hardirqs_on+0x8c/0x130 ? __raw_spin_unlock_irqrestore+0x5d/0x80 ? __raw_spin_unlock_irqrestore+0x46/0x80 ? devm_ioremap_wc+0x9a/0xd0 ena_probe+0x4d2/0x1b20 [ena] ? __lock_acquire+0x56a/0xbd0 ? __pfx_ena_probe+0x10/0x10 [ena] ? local_clock+0x15/0x30 ? __lock_release.isra.0+0x1c9/0x340 ? mark_held_locks+0x40/0x70 ? lockdep_hardirqs_on_prepare.part.0+0x92/0x170 ? trace_hardirqs_on+0x18/0x140 ? lockdep_hardirqs_on+0x8c/0x130 ? __raw_spin_unlock_irqrestore+0x5d/0x80 ? __raw_spin_unlock_irqrestore+0x46/0x80 ? __pfx_ena_probe+0x10/0x10 [ena] ...... </TASK> Fixes: 816b526 ("net: ena: Control PHC enable through devlink") Signed-off-by: Frank Liang <xiliang@redhat.com> Reviewed-by: David Arinzon <darinzon@amazon.com> Reviewed-by: Jiri Pirko <jiri@nvidia.com> Link: https://patch.msgid.link/20251231145808.6103-1-xiliang@redhat.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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…te in qfq_reset `qfq_class->leaf_qdisc->q.qlen > 0` does not imply that the class itself is active. Two qfq_class objects may point to the same leaf_qdisc. This happens when: 1. one QFQ qdisc is attached to the dev as the root qdisc, and 2. another QFQ qdisc is temporarily referenced (e.g., via qdisc_get() / qdisc_put()) and is pending to be destroyed, as in function tc_new_tfilter. When packets are enqueued through the root QFQ qdisc, the shared leaf_qdisc->q.qlen increases. At the same time, the second QFQ qdisc triggers qdisc_put and qdisc_destroy: the qdisc enters qfq_reset() with its own q->q.qlen == 0, but its class's leaf qdisc->q.qlen > 0. Therefore, the qfq_reset would wrongly deactivate an inactive aggregate and trigger a null-deref in qfq_deactivate_agg: [ 0.903172] BUG: kernel NULL pointer dereference, address: 0000000000000000 [ 0.903571] #PF: supervisor write access in kernel mode [ 0.903860] #PF: error_code(0x0002) - not-present page [ 0.904177] PGD 10299b067 P4D 10299b067 PUD 10299c067 PMD 0 [ 0.904502] Oops: Oops: 0002 [#1] SMP NOPTI [ 0.904737] CPU: 0 UID: 0 PID: 135 Comm: exploit Not tainted 6.19.0-rc3+ #2 NONE [ 0.905157] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.17.0-0-gb52ca86e094d-prebuilt.qemu.org 04/01/2014 [ 0.905754] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2)) [ 0.906046] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0 Code starting with the faulting instruction =========================================== 0: 0f 84 4d 01 00 00 je 0x153 6: 48 89 70 18 mov %rsi,0x18(%rax) a: 8b 4b 10 mov 0x10(%rbx),%ecx d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx 14: 48 8b 78 08 mov 0x8(%rax),%rdi 18: 48 d3 e2 shl %cl,%rdx 1b: 48 21 f2 and %rsi,%rdx 1e: 48 2b 13 sub (%rbx),%rdx 21: 48 8b 30 mov (%rax),%rsi 24: 48 d3 ea shr %cl,%rdx 27: 8b 4b 18 mov 0x18(%rbx),%ecx ... [ 0.907095] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246 [ 0.907368] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000 [ 0.907723] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 0.908100] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000 [ 0.908451] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000 [ 0.908804] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880 [ 0.909179] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000 [ 0.909572] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.909857] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0 [ 0.910247] PKRU: 55555554 [ 0.910391] Call Trace: [ 0.910527] <TASK> [ 0.910638] qfq_reset_qdisc (net/sched/sch_qfq.c:357 net/sched/sch_qfq.c:1485) [ 0.910826] qdisc_reset (include/linux/skbuff.h:2195 include/linux/skbuff.h:2501 include/linux/skbuff.h:3424 include/linux/skbuff.h:3430 net/sched/sch_generic.c:1036) [ 0.911040] __qdisc_destroy (net/sched/sch_generic.c:1076) [ 0.911236] tc_new_tfilter (net/sched/cls_api.c:2447) [ 0.911447] rtnetlink_rcv_msg (net/core/rtnetlink.c:6958) [ 0.911663] ? __pfx_rtnetlink_rcv_msg (net/core/rtnetlink.c:6861) [ 0.911894] netlink_rcv_skb (net/netlink/af_netlink.c:2550) [ 0.912100] netlink_unicast (net/netlink/af_netlink.c:1319 net/netlink/af_netlink.c:1344) [ 0.912296] ? __alloc_skb (net/core/skbuff.c:706) [ 0.912484] netlink_sendmsg (net/netlink/af_netlink.c:1894) [ 0.912682] sock_write_iter (net/socket.c:727 (discriminator 1) net/socket.c:742 (discriminator 1) net/socket.c:1195 (discriminator 1)) [ 0.912880] vfs_write (fs/read_write.c:593 fs/read_write.c:686) [ 0.913077] ksys_write (fs/read_write.c:738) [ 0.913252] do_syscall_64 (arch/x86/entry/syscall_64.c:63 (discriminator 1) arch/x86/entry/syscall_64.c:94 (discriminator 1)) [ 0.913438] entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:131) [ 0.913687] RIP: 0033:0x424c34 [ 0.913844] Code: 89 02 48 c7 c0 ff ff ff ff eb bd 66 2e 0f 1f 84 00 00 00 00 00 90 f3 0f 1e fa 80 3d 2d 44 09 00 00 74 13 b8 01 00 00 00 0f 05 9 Code starting with the faulting instruction =========================================== 0: 89 02 mov %eax,(%rdx) 2: 48 c7 c0 ff ff ff ff mov $0xffffffffffffffff,%rax 9: eb bd jmp 0xffffffffffffffc8 b: 66 2e 0f 1f 84 00 00 cs nopw 0x0(%rax,%rax,1) 12: 00 00 00 15: 90 nop 16: f3 0f 1e fa endbr64 1a: 80 3d 2d 44 09 00 00 cmpb $0x0,0x9442d(%rip) # 0x9444e 21: 74 13 je 0x36 23: b8 01 00 00 00 mov $0x1,%eax 28: 0f 05 syscall 2a: 09 .byte 0x9 [ 0.914807] RSP: 002b:00007ffea1938b78 EFLAGS: 00000202 ORIG_RAX: 0000000000000001 [ 0.915197] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000424c34 [ 0.915556] RDX: 000000000000003c RSI: 000000002af378c0 RDI: 0000000000000003 [ 0.915912] RBP: 00007ffea1938bc0 R08: 00000000004b8820 R09: 0000000000000000 [ 0.916297] R10: 0000000000000001 R11: 0000000000000202 R12: 00007ffea1938d28 [ 0.916652] R13: 00007ffea1938d38 R14: 00000000004b3828 R15: 0000000000000001 [ 0.917039] </TASK> [ 0.917158] Modules linked in: [ 0.917316] CR2: 0000000000000000 [ 0.917484] ---[ end trace 0000000000000000 ]--- [ 0.917717] RIP: 0010:qfq_deactivate_agg (include/linux/list.h:992 (discriminator 2) include/linux/list.h:1006 (discriminator 2) net/sched/sch_qfq.c:1367 (discriminator 2) net/sched/sch_qfq.c:1393 (discriminator 2)) [ 0.917978] Code: 0f 84 4d 01 00 00 48 89 70 18 8b 4b 10 48 c7 c2 ff ff ff ff 48 8b 78 08 48 d3 e2 48 21 f2 48 2b 13 48 8b 30 48 d3 ea 8b 4b 18 0 Code starting with the faulting instruction =========================================== 0: 0f 84 4d 01 00 00 je 0x153 6: 48 89 70 18 mov %rsi,0x18(%rax) a: 8b 4b 10 mov 0x10(%rbx),%ecx d: 48 c7 c2 ff ff ff ff mov $0xffffffffffffffff,%rdx 14: 48 8b 78 08 mov 0x8(%rax),%rdi 18: 48 d3 e2 shl %cl,%rdx 1b: 48 21 f2 and %rsi,%rdx 1e: 48 2b 13 sub (%rbx),%rdx 21: 48 8b 30 mov (%rax),%rsi 24: 48 d3 ea shr %cl,%rdx 27: 8b 4b 18 mov 0x18(%rbx),%ecx ... [ 0.918902] RSP: 0018:ffffc900004a39a0 EFLAGS: 00010246 [ 0.919198] RAX: ffff8881043a0880 RBX: ffff888102953340 RCX: 0000000000000000 [ 0.919559] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 0.919908] RBP: ffff888102952180 R08: 0000000000000000 R09: 0000000000000000 [ 0.920289] R10: ffff8881043a0000 R11: 0000000000000000 R12: ffff888102952000 [ 0.920648] R13: ffff888102952180 R14: ffff8881043a0ad8 R15: ffff8881043a0880 [ 0.921014] FS: 000000002a1a0380(0000) GS:ffff888196d8d000(0000) knlGS:0000000000000000 [ 0.921424] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 0.921710] CR2: 0000000000000000 CR3: 0000000102993002 CR4: 0000000000772ef0 [ 0.922097] PKRU: 55555554 [ 0.922240] Kernel panic - not syncing: Fatal exception [ 0.922590] Kernel Offset: disabled Fixes: 0545a30 ("pkt_sched: QFQ - quick fair queue scheduler") Signed-off-by: Xiang Mei <xmei5@asu.edu> Link: https://patch.msgid.link/20260106034100.1780779-1-xmei5@asu.edu Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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Protect the reset path from callbacks by setting the netdevs to detached state and close any netdevs in UP state until the reset handling has completed. During a reset, the driver will de-allocate resources for the vport, and there is no guarantee that those will recover, which is why the existing vport_ctrl_lock does not provide sufficient protection. idpf_detach_and_close() is called right before reset handling. If the reset handling succeeds, the netdevs state is recovered via call to idpf_attach_and_open(). If the reset handling fails the netdevs remain down. The detach/down calls are protected with RTNL lock to avoid racing with callbacks. On the recovery side the attach can be done without holding the RTNL lock as there are no callbacks expected at that point, due to detach/close always being done first in that flow. The previous logic restoring the netdevs state based on the IDPF_VPORT_UP_REQUESTED flag in the init task is not needed anymore, hence the removal of idpf_set_vport_state(). The IDPF_VPORT_UP_REQUESTED is still being used to restore the state of the netdevs following the reset, but has no use outside of the reset handling flow. idpf_init_hard_reset() is converted to void, since it was used as such and there is no error handling being done based on its return value. Before this change, invoking hard and soft resets simultaneously will cause the driver to lose the vport state: ip -br a <inf> UP echo 1 > /sys/class/net/ens801f0/device/reset& \ ethtool -L ens801f0 combined 8 ip -br a <inf> DOWN ip link set <inf> up ip -br a <inf> DOWN Also in case of a failure in the reset path, the netdev is left exposed to external callbacks, while vport resources are not initialized, leading to a crash on subsequent ifup/down: [408471.398966] idpf 0000:83:00.0: HW reset detected [408471.411744] idpf 0000:83:00.0: Device HW Reset initiated [408472.277901] idpf 0000:83:00.0: The driver was unable to contact the device's firmware. Check that the FW is running. Driver state= 0x2 [408508.125551] BUG: kernel NULL pointer dereference, address: 0000000000000078 [408508.126112] #PF: supervisor read access in kernel mode [408508.126687] #PF: error_code(0x0000) - not-present page [408508.127256] PGD 2aae2f067 P4D 0 [408508.127824] Oops: Oops: 0000 [#1] SMP NOPTI ... [408508.130871] RIP: 0010:idpf_stop+0x39/0x70 [idpf] ... [408508.139193] Call Trace: [408508.139637] <TASK> [408508.140077] __dev_close_many+0xbb/0x260 [408508.140533] __dev_change_flags+0x1cf/0x280 [408508.140987] netif_change_flags+0x26/0x70 [408508.141434] dev_change_flags+0x3d/0xb0 [408508.141878] devinet_ioctl+0x460/0x890 [408508.142321] inet_ioctl+0x18e/0x1d0 [408508.142762] ? _copy_to_user+0x22/0x70 [408508.143207] sock_do_ioctl+0x3d/0xe0 [408508.143652] sock_ioctl+0x10e/0x330 [408508.144091] ? find_held_lock+0x2b/0x80 [408508.144537] __x64_sys_ioctl+0x96/0xe0 [408508.144979] do_syscall_64+0x79/0x3d0 [408508.145415] entry_SYSCALL_64_after_hwframe+0x76/0x7e [408508.145860] RIP: 0033:0x7f3e0bb4caff Fixes: 0fe4546 ("idpf: add create vport and netdev configuration") Signed-off-by: Emil Tantilov <emil.s.tantilov@intel.com> Reviewed-by: Madhu Chittim <madhu.chittim@intel.com> Tested-by: Samuel Salin <Samuel.salin@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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The RSS LUT is not initialized until the interface comes up, causing the following NULL pointer crash when ethtool operations like rxhash on/off are performed before the interface is brought up for the first time. Move RSS LUT initialization from ndo_open to vport creation to ensure LUT is always available. This enables RSS configuration via ethtool before bringing the interface up. Simplify LUT management by maintaining all changes in the driver's soft copy and programming zeros to the indirection table when rxhash is disabled. Defer HW programming until the interface comes up if it is down during rxhash and LUT configuration changes. Steps to reproduce: ** Load idpf driver; interfaces will be created modprobe idpf ** Before bringing the interfaces up, turn rxhash off ethtool -K eth2 rxhash off [89408.371875] BUG: kernel NULL pointer dereference, address: 0000000000000000 [89408.371908] #PF: supervisor read access in kernel mode [89408.371924] #PF: error_code(0x0000) - not-present page [89408.371940] PGD 0 P4D 0 [89408.371953] Oops: Oops: 0000 [#1] SMP NOPTI <snip> [89408.372052] RIP: 0010:memcpy_orig+0x16/0x130 [89408.372310] Call Trace: [89408.372317] <TASK> [89408.372326] ? idpf_set_features+0xfc/0x180 [idpf] [89408.372363] __netdev_update_features+0x295/0xde0 [89408.372384] ethnl_set_features+0x15e/0x460 [89408.372406] genl_family_rcv_msg_doit+0x11f/0x180 [89408.372429] genl_rcv_msg+0x1ad/0x2b0 [89408.372446] ? __pfx_ethnl_set_features+0x10/0x10 [89408.372465] ? __pfx_genl_rcv_msg+0x10/0x10 [89408.372482] netlink_rcv_skb+0x58/0x100 [89408.372502] genl_rcv+0x2c/0x50 [89408.372516] netlink_unicast+0x289/0x3e0 [89408.372533] netlink_sendmsg+0x215/0x440 [89408.372551] __sys_sendto+0x234/0x240 [89408.372571] __x64_sys_sendto+0x28/0x30 [89408.372585] x64_sys_call+0x1909/0x1da0 [89408.372604] do_syscall_64+0x7a/0xfa0 [89408.373140] ? clear_bhb_loop+0x60/0xb0 [89408.373647] entry_SYSCALL_64_after_hwframe+0x76/0x7e [89408.378887] </TASK> <snip> Fixes: a251eee ("idpf: add SRIOV support and other ndo_ops") Signed-off-by: Sreedevi Joshi <sreedevi.joshi@intel.com> Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Reviewed-by: Emil Tantilov <emil.s.tantilov@intel.com> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Reviewed-by: Paul Menzel <pmenzel@molgen.mpg.de> Reviewed-by: Simon Horman <horms@kernel.org> Tested-by: Samuel Salin <Samuel.salin@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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During soft reset, the RSS LUT is freed and not restored unless the interface is up. If an ethtool command that accesses the rss lut is attempted immediately after reset, it will result in NULL ptr dereference. Also, there is no need to reset the rss lut if the soft reset does not involve queue count change. After soft reset, set the RSS LUT to default values based on the updated queue count only if the reset was a result of a queue count change and the LUT was not configured by the user. In all other cases, don't touch the LUT. Steps to reproduce: ** Bring the interface down (if up) ifconfig eth1 down ** update the queue count (eg., 27->20) ethtool -L eth1 combined 20 ** display the RSS LUT ethtool -x eth1 [82375.558338] BUG: kernel NULL pointer dereference, address: 0000000000000000 [82375.558373] #PF: supervisor read access in kernel mode [82375.558391] #PF: error_code(0x0000) - not-present page [82375.558408] PGD 0 P4D 0 [82375.558421] Oops: Oops: 0000 [#1] SMP NOPTI <snip> [82375.558516] RIP: 0010:idpf_get_rxfh+0x108/0x150 [idpf] [82375.558786] Call Trace: [82375.558793] <TASK> [82375.558804] rss_prepare.isra.0+0x187/0x2a0 [82375.558827] rss_prepare_data+0x3a/0x50 [82375.558845] ethnl_default_doit+0x13d/0x3e0 [82375.558863] genl_family_rcv_msg_doit+0x11f/0x180 [82375.558886] genl_rcv_msg+0x1ad/0x2b0 [82375.558902] ? __pfx_ethnl_default_doit+0x10/0x10 [82375.558920] ? __pfx_genl_rcv_msg+0x10/0x10 [82375.558937] netlink_rcv_skb+0x58/0x100 [82375.558957] genl_rcv+0x2c/0x50 [82375.558971] netlink_unicast+0x289/0x3e0 [82375.558988] netlink_sendmsg+0x215/0x440 [82375.559005] __sys_sendto+0x234/0x240 [82375.559555] __x64_sys_sendto+0x28/0x30 [82375.560068] x64_sys_call+0x1909/0x1da0 [82375.560576] do_syscall_64+0x7a/0xfa0 [82375.561076] ? clear_bhb_loop+0x60/0xb0 [82375.561567] entry_SYSCALL_64_after_hwframe+0x76/0x7e <snip> Fixes: 02cbfba ("idpf: add ethtool callbacks") Signed-off-by: Sreedevi Joshi <sreedevi.joshi@intel.com> Reviewed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com> Reviewed-by: Sridhar Samudrala <sridhar.samudrala@intel.com> Reviewed-by: Emil Tantilov <emil.s.tantilov@intel.com> Reviewed-by: Simon Horman <horms@kernel.org> Tested-by: Samuel Salin <Samuel.salin@intel.com> Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
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During GPU reset, VBlank interrupts are disabled which causes drm_fb_helper_fb_dirty() to wait for VBlank timeout. This will create call traces like (seen on an RX7900 series dGPU): [ 101.313646] ------------[ cut here ]------------ [ 101.313648] amdgpu 0000:03:00.0: [drm] vblank wait timed out on crtc 0 [ 101.313657] WARNING: CPU: 0 PID: 461 at drivers/gpu/drm/drm_vblank.c:1320 drm_wait_one_vblank+0x176/0x220 [ 101.313663] Modules linked in: amdgpu amdxcp drm_panel_backlight_quirks gpu_sched drm_buddy drm_ttm_helper ttm drm_exec drm_suballoc_helper drm_display_helper cec rc_core i2c_algo_bit nf_conntrack_netlink xt_nat xt_tcpudp veth xt_conntrack xt_MASQUERADE bridge stp llc xfrm_user xfrm_algo xt_set ip_set nft_chain_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 xt_addrtype nft_compat x_tables nf_tables overlay qrtr sunrpc snd_hda_codec_alc882 snd_hda_codec_realtek_lib snd_hda_codec_generic snd_hda_codec_atihdmi snd_hda_codec_hdmi snd_hda_intel snd_hda_codec snd_hda_core snd_intel_dspcfg snd_intel_sdw_acpi snd_hwdep snd_pcm amd_atl intel_rapl_msr snd_seq_midi intel_rapl_common asus_ec_sensors snd_seq_midi_event snd_rawmidi snd_seq eeepc_wmi snd_seq_device edac_mce_amd asus_wmi polyval_clmulni ghash_clmulni_intel snd_timer platform_profile aesni_intel wmi_bmof sparse_keymap joydev snd rapl input_leds i2c_piix4 soundcore ccp k10temp i2c_smbus gpio_amdpt mac_hid binfmt_misc sch_fq_codel msr parport_pc ppdev lp parport [ 101.313745] efi_pstore nfnetlink dmi_sysfs autofs4 hid_generic usbhid hid r8169 realtek ahci libahci video wmi [ 101.313760] CPU: 0 UID: 0 PID: 461 Comm: kworker/0:2 Not tainted 6.18.0-rc6-174403b3b920 #1 PREEMPT(voluntary) [ 101.313763] Hardware name: ASUS System Product Name/TUF GAMING X670E-PLUS, BIOS 0821 11/15/2022 [ 101.313765] Workqueue: events drm_fb_helper_damage_work [ 101.313769] RIP: 0010:drm_wait_one_vblank+0x176/0x220 [ 101.313772] Code: 7c 24 08 4c 8b 77 50 4d 85 f6 0f 84 a1 00 00 00 e8 2f 11 03 00 44 89 e9 4c 89 f2 48 c7 c7 d0 ad 0d a8 48 89 c6 e8 2a e0 4a ff <0f> 0b e9 f2 fe ff ff 48 85 ff 74 04 4c 8b 67 08 4d 8b 6c 24 50 4d [ 101.313774] RSP: 0018:ffffc99c00d47d68 EFLAGS: 00010246 [ 101.313777] RAX: 0000000000000000 RBX: 000000000200038a RCX: 0000000000000000 [ 101.313778] RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 [ 101.313779] RBP: ffffc99c00d47dc0 R08: 0000000000000000 R09: 0000000000000000 [ 101.313781] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8948c4280010 [ 101.313782] R13: 0000000000000000 R14: ffff894883263a50 R15: ffff89488c384830 [ 101.313784] FS: 0000000000000000(0000) GS:ffff895424692000(0000) knlGS:0000000000000000 [ 101.313785] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 101.313787] CR2: 00007773650ee200 CR3: 0000000588e40000 CR4: 0000000000f50ef0 [ 101.313788] PKRU: 55555554 [ 101.313790] Call Trace: [ 101.313791] <TASK> [ 101.313795] ? __pfx_autoremove_wake_function+0x10/0x10 [ 101.313800] drm_crtc_wait_one_vblank+0x17/0x30 [ 101.313802] drm_client_modeset_wait_for_vblank+0x61/0x80 [ 101.313805] drm_fb_helper_damage_work+0x46/0x1a0 [ 101.313808] process_one_work+0x1a1/0x3f0 [ 101.313812] worker_thread+0x2ba/0x3d0 [ 101.313816] kthread+0x107/0x220 [ 101.313818] ? __pfx_worker_thread+0x10/0x10 [ 101.313821] ? __pfx_kthread+0x10/0x10 [ 101.313823] ret_from_fork+0x202/0x230 [ 101.313826] ? __pfx_kthread+0x10/0x10 [ 101.313828] ret_from_fork_asm+0x1a/0x30 [ 101.313834] </TASK> [ 101.313835] ---[ end trace 0000000000000000 ]--- Cancel pending damage work synchronously before console_lock() to ensure any in-flight framebuffer damage operations complete before suspension. Also check for FBINFO_STATE_RUNNING in drm_fb_helper_damage_work() to avoid executing damage work if it is rescheduled while the device is suspended. Fixes: d8c4bdd ("drm/fb-helper: Synchronize dirty worker with vblank") Signed-off-by: Aurabindo Pillai <aurabindo.pillai@amd.com> Signed-off-by: Chengjun Yao <Chengjun.Yao@amd.com> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de> Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de> Link: https://patch.msgid.link/20251215081822.432005-1-Chengjun.Yao@amd.com
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If two drivers were calling gpiochip_add_data_with_key(), one may be traversing the srcu-protected list in gpio_name_to_desc(), meanwhile other has just added its gdev in gpiodev_add_to_list_unlocked(). This creates a non-mutexed and non-protected timeframe, when one instance is dereferencing and using &gdev->srcu, before the other has initialized it, resulting in crash: [ 4.935481] Unable to handle kernel paging request at virtual address ffff800272bcc000 [ 4.943396] Mem abort info: [ 4.943400] ESR = 0x0000000096000005 [ 4.943403] EC = 0x25: DABT (current EL), IL = 32 bits [ 4.943407] SET = 0, FnV = 0 [ 4.943410] EA = 0, S1PTW = 0 [ 4.943413] FSC = 0x05: level 1 translation fault [ 4.943416] Data abort info: [ 4.943418] ISV = 0, ISS = 0x00000005, ISS2 = 0x00000000 [ 4.946220] CM = 0, WnR = 0, TnD = 0, TagAccess = 0 [ 4.955261] GCS = 0, Overlay = 0, DirtyBit = 0, Xs = 0 [ 4.955268] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000038e6c000 [ 4.961449] [ffff800272bcc000] pgd=0000000000000000 [ 4.969203] , p4d=1000000039739003 [ 4.979730] , pud=0000000000000000 [ 4.980210] phandle (CPU): 0x0000005e, phandle (BE): 0x5e000000 for node "reset" [ 4.991736] Internal error: Oops: 0000000096000005 [#1] PREEMPT SMP ... [ 5.121359] pc : __srcu_read_lock+0x44/0x98 [ 5.131091] lr : gpio_name_to_desc+0x60/0x1a0 [ 5.153671] sp : ffff8000833bb430 [ 5.298440] [ 5.298443] Call trace: [ 5.298445] __srcu_read_lock+0x44/0x98 [ 5.309484] gpio_name_to_desc+0x60/0x1a0 [ 5.320692] gpiochip_add_data_with_key+0x488/0xf00 5.946419] ---[ end trace 0000000000000000 ]--- Move initialization code for gdev fields before it is added to gpio_devices, with adjacent initialization code. Adjust goto statements to reflect modified order of operations Fixes: 47d8b4c ("gpio: add SRCU infrastructure to struct gpio_device") Reviewed-by: Jakub Lewalski <jakub.lewalski@nokia.com> Signed-off-by: Paweł Narewski <pawel.narewski@nokia.com> [Bartosz: fixed a build issue, removed stray newline] Link: https://lore.kernel.org/r/20251224082641.10769-1-bartosz.golaszewski@oss.qualcomm.com Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
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The GPIO controller is configured as non-sleeping but it uses generic
pinctrl helpers which use a mutex for synchronization.
This can cause the following lockdep splat with shared GPIOs enabled on
boards which have multiple devices using the same GPIO:
BUG: sleeping function called from invalid context at
kernel/locking/mutex.c:591
in_atomic(): 1, irqs_disabled(): 1, non_block: 0, pid: 12, name:
kworker/u16:0
preempt_count: 1, expected: 0
RCU nest depth: 0, expected: 0
6 locks held by kworker/u16:0/12:
#0: ffff0001f0018d48 ((wq_completion)events_unbound#2){+.+.}-{0:0},
at: process_one_work+0x18c/0x604
#1: ffff8000842dbdf0 (deferred_probe_work){+.+.}-{0:0}, at:
process_one_work+0x1b4/0x604
#2: ffff0001f18498f8 (&dev->mutex){....}-{4:4}, at:
__device_attach+0x38/0x1b0
#3: ffff0001f75f1e90 (&gdev->srcu){.+.?}-{0:0}, at:
gpiod_direction_output_raw_commit+0x0/0x360
#4: ffff0001f46e3db8 (&shared_desc->spinlock){....}-{3:3}, at:
gpio_shared_proxy_direction_output+0xd0/0x144 [gpio_shared_proxy]
#5: ffff0001f180ee90 (&gdev->srcu){.+.?}-{0:0}, at:
gpiod_direction_output_raw_commit+0x0/0x360
irq event stamp: 81450
hardirqs last enabled at (81449): [<ffff8000813acba4>]
_raw_spin_unlock_irqrestore+0x74/0x78
hardirqs last disabled at (81450): [<ffff8000813abfb8>]
_raw_spin_lock_irqsave+0x84/0x88
softirqs last enabled at (79616): [<ffff8000811455fc>]
__alloc_skb+0x17c/0x1e8
softirqs last disabled at (79614): [<ffff8000811455fc>]
__alloc_skb+0x17c/0x1e8
CPU: 2 UID: 0 PID: 12 Comm: kworker/u16:0 Not tainted
6.19.0-rc4-next-20260105+ #11975 PREEMPT
Hardware name: Hardkernel ODROID-M1 (DT)
Workqueue: events_unbound deferred_probe_work_func
Call trace:
show_stack+0x18/0x24 (C)
dump_stack_lvl+0x90/0xd0
dump_stack+0x18/0x24
__might_resched+0x144/0x248
__might_sleep+0x48/0x98
__mutex_lock+0x5c/0x894
mutex_lock_nested+0x24/0x30
pinctrl_get_device_gpio_range+0x44/0x128
pinctrl_gpio_direction+0x3c/0xe0
pinctrl_gpio_direction_output+0x14/0x20
rockchip_gpio_direction_output+0xb8/0x19c
gpiochip_direction_output+0x38/0x94
gpiod_direction_output_raw_commit+0x1d8/0x360
gpiod_direction_output_nonotify+0x7c/0x230
gpiod_direction_output+0x34/0xf8
gpio_shared_proxy_direction_output+0xec/0x144 [gpio_shared_proxy]
gpiochip_direction_output+0x38/0x94
gpiod_direction_output_raw_commit+0x1d8/0x360
gpiod_direction_output_nonotify+0x7c/0x230
gpiod_configure_flags+0xbc/0x480
gpiod_find_and_request+0x1a0/0x574
gpiod_get_index+0x58/0x84
devm_gpiod_get_index+0x20/0xb4
devm_gpiod_get_optional+0x18/0x30
rockchip_pcie_probe+0x98/0x380
platform_probe+0x5c/0xac
really_probe+0xbc/0x298
Fixes: 936ee26 ("gpio/rockchip: add driver for rockchip gpio")
Cc: stable@vger.kernel.org
Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
Closes: https://lore.kernel.org/all/d035fc29-3b03-4cd6-b8ec-001f93540bc6@samsung.com/
Acked-by: Heiko Stuebner <heiko@sntech.de>
Link: https://lore.kernel.org/r/20260106090011.21603-1-bartosz.golaszewski@oss.qualcomm.com
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@oss.qualcomm.com>
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…ked_inode()
In btrfs_read_locked_inode() we are calling btrfs_init_file_extent_tree()
while holding a path with a read locked leaf from a subvolume tree, and
btrfs_init_file_extent_tree() may do a GFP_KERNEL allocation, which can
trigger reclaim.
This can create a circular lock dependency which lockdep warns about with
the following splat:
[6.1433] ======================================================
[6.1574] WARNING: possible circular locking dependency detected
[6.1583] 6.18.0+ #4 Tainted: G U
[6.1591] ------------------------------------------------------
[6.1599] kswapd0/117 is trying to acquire lock:
[6.1606] ffff8d9b6333c5b8 (&delayed_node->mutex){+.+.}-{3:3}, at: __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1625]
but task is already holding lock:
[6.1633] ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60
[6.1646]
which lock already depends on the new lock.
[6.1657]
the existing dependency chain (in reverse order) is:
[6.1667]
-> #2 (fs_reclaim){+.+.}-{0:0}:
[6.1677] fs_reclaim_acquire+0x9d/0xd0
[6.1685] __kmalloc_cache_noprof+0x59/0x750
[6.1694] btrfs_init_file_extent_tree+0x90/0x100
[6.1702] btrfs_read_locked_inode+0xc3/0x6b0
[6.1710] btrfs_iget+0xbb/0xf0
[6.1716] btrfs_lookup_dentry+0x3c5/0x8e0
[6.1724] btrfs_lookup+0x12/0x30
[6.1731] lookup_open.isra.0+0x1aa/0x6a0
[6.1739] path_openat+0x5f7/0xc60
[6.1746] do_filp_open+0xd6/0x180
[6.1753] do_sys_openat2+0x8b/0xe0
[6.1760] __x64_sys_openat+0x54/0xa0
[6.1768] do_syscall_64+0x97/0x3e0
[6.1776] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[6.1784]
-> #1 (btrfs-tree-00){++++}-{3:3}:
[6.1794] lock_release+0x127/0x2a0
[6.1801] up_read+0x1b/0x30
[6.1808] btrfs_search_slot+0x8e0/0xff0
[6.1817] btrfs_lookup_inode+0x52/0xd0
[6.1825] __btrfs_update_delayed_inode+0x73/0x520
[6.1833] btrfs_commit_inode_delayed_inode+0x11a/0x120
[6.1842] btrfs_log_inode+0x608/0x1aa0
[6.1849] btrfs_log_inode_parent+0x249/0xf80
[6.1857] btrfs_log_dentry_safe+0x3e/0x60
[6.1865] btrfs_sync_file+0x431/0x690
[6.1872] do_fsync+0x39/0x80
[6.1879] __x64_sys_fsync+0x13/0x20
[6.1887] do_syscall_64+0x97/0x3e0
[6.1894] entry_SYSCALL_64_after_hwframe+0x76/0x7e
[6.1903]
-> #0 (&delayed_node->mutex){+.+.}-{3:3}:
[6.1913] __lock_acquire+0x15e9/0x2820
[6.1920] lock_acquire+0xc9/0x2d0
[6.1927] __mutex_lock+0xcc/0x10a0
[6.1934] __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1944] btrfs_evict_inode+0x20b/0x4b0
[6.1952] evict+0x15a/0x2f0
[6.1958] prune_icache_sb+0x91/0xd0
[6.1966] super_cache_scan+0x150/0x1d0
[6.1974] do_shrink_slab+0x155/0x6f0
[6.1981] shrink_slab+0x48e/0x890
[6.1988] shrink_one+0x11a/0x1f0
[6.1995] shrink_node+0xbfd/0x1320
[6.1002] balance_pgdat+0x67f/0xc60
[6.1321] kswapd+0x1dc/0x3e0
[6.1643] kthread+0xff/0x240
[6.1965] ret_from_fork+0x223/0x280
[6.1287] ret_from_fork_asm+0x1a/0x30
[6.1616]
other info that might help us debug this:
[6.1561] Chain exists of:
&delayed_node->mutex --> btrfs-tree-00 --> fs_reclaim
[6.1503] Possible unsafe locking scenario:
[6.1110] CPU0 CPU1
[6.1411] ---- ----
[6.1707] lock(fs_reclaim);
[6.1998] lock(btrfs-tree-00);
[6.1291] lock(fs_reclaim);
[6.1581] lock(&delayed_node->mutex);
[6.1874]
*** DEADLOCK ***
[6.1716] 2 locks held by kswapd0/117:
[6.1999] #0: ffffffffa4ab8ce0 (fs_reclaim){+.+.}-{0:0}, at: balance_pgdat+0x195/0xc60
[6.1294] #1: ffff8d998344b0e0 (&type->s_umount_key#40){++++}- {3:3}, at: super_cache_scan+0x37/0x1d0
[6.1596]
stack backtrace:
[6.1183] CPU: 11 UID: 0 PID: 117 Comm: kswapd0 Tainted: G U 6.18.0+ #4 PREEMPT(lazy)
[6.1185] Tainted: [U]=USER
[6.1186] Hardware name: ASUS System Product Name/PRIME B560M-A AC, BIOS 2001 02/01/2023
[6.1187] Call Trace:
[6.1187] <TASK>
[6.1189] dump_stack_lvl+0x6e/0xa0
[6.1192] print_circular_bug.cold+0x17a/0x1c0
[6.1194] check_noncircular+0x175/0x190
[6.1197] __lock_acquire+0x15e9/0x2820
[6.1200] lock_acquire+0xc9/0x2d0
[6.1201] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1204] __mutex_lock+0xcc/0x10a0
[6.1206] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1208] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1211] ? __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1213] __btrfs_release_delayed_node.part.0+0x39/0x2f0
[6.1215] btrfs_evict_inode+0x20b/0x4b0
[6.1217] ? lock_acquire+0xc9/0x2d0
[6.1220] evict+0x15a/0x2f0
[6.1222] prune_icache_sb+0x91/0xd0
[6.1224] super_cache_scan+0x150/0x1d0
[6.1226] do_shrink_slab+0x155/0x6f0
[6.1228] shrink_slab+0x48e/0x890
[6.1229] ? shrink_slab+0x2d2/0x890
[6.1231] shrink_one+0x11a/0x1f0
[6.1234] shrink_node+0xbfd/0x1320
[6.1236] ? shrink_node+0xa2d/0x1320
[6.1236] ? shrink_node+0xbd3/0x1320
[6.1239] ? balance_pgdat+0x67f/0xc60
[6.1239] balance_pgdat+0x67f/0xc60
[6.1241] ? finish_task_switch.isra.0+0xc4/0x2a0
[6.1246] kswapd+0x1dc/0x3e0
[6.1247] ? __pfx_autoremove_wake_function+0x10/0x10
[6.1249] ? __pfx_kswapd+0x10/0x10
[6.1250] kthread+0xff/0x240
[6.1251] ? __pfx_kthread+0x10/0x10
[6.1253] ret_from_fork+0x223/0x280
[6.1255] ? __pfx_kthread+0x10/0x10
[6.1257] ret_from_fork_asm+0x1a/0x30
[6.1260] </TASK>
This is because:
1) The fsync task is holding an inode's delayed node mutex (for a
directory) while calling __btrfs_update_delayed_inode() and that needs
to do a search on the subvolume's btree (therefore read lock some
extent buffers);
2) The lookup task, at btrfs_lookup(), triggered reclaim with the
GFP_KERNEL allocation done by btrfs_init_file_extent_tree() while
holding a read lock on a subvolume leaf;
3) The reclaim triggered kswapd which is doing inode eviction for the
directory inode the fsync task is using as an argument to
btrfs_commit_inode_delayed_inode() - but in that call chain we are
trying to read lock the same leaf that the lookup task is holding
while calling btrfs_init_file_extent_tree() and doing the GFP_KERNEL
allocation.
Fix this by calling btrfs_init_file_extent_tree() after we don't need the
path anymore and release it in btrfs_read_locked_inode().
Reported-by: Thomas Hellström <thomas.hellstrom@linux.intel.com>
Link: https://lore.kernel.org/linux-btrfs/6e55113a22347c3925458a5d840a18401a38b276.camel@linux.intel.com/
Fixes: 8679d26 ("btrfs: initialize inode::file_extent_tree after i_mode has been set")
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
teawater
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Jan 16, 2026
An IRQ handler can either be IRQF_NO_THREAD or acquire spinlock_t, as CONFIG_PROVE_RAW_LOCK_NESTING warns: ============================= [ BUG: Invalid wait context ] 6.18.0-rc1+git... #1 ----------------------------- some-user-space-process/1251 is trying to lock: (&counter->events_list_lock){....}-{3:3}, at: counter_push_event [counter] other info that might help us debug this: context-{2:2} no locks held by some-user-space-process/.... stack backtrace: CPU: 0 UID: 0 PID: 1251 Comm: some-user-space-process 6.18.0-rc1+git... #1 PREEMPT Call trace: show_stack (C) dump_stack_lvl dump_stack __lock_acquire lock_acquire _raw_spin_lock_irqsave counter_push_event [counter] interrupt_cnt_isr [interrupt_cnt] __handle_irq_event_percpu handle_irq_event handle_simple_irq handle_irq_desc generic_handle_domain_irq gpio_irq_handler handle_irq_desc generic_handle_domain_irq gic_handle_irq call_on_irq_stack do_interrupt_handler el0_interrupt __el0_irq_handler_common el0t_64_irq_handler el0t_64_irq ... and Sebastian correctly points out. Remove IRQF_NO_THREAD as an alternative to switching to raw_spinlock_t, because the latter would limit all potential nested locks to raw_spinlock_t only. Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/all/20251117151314.xwLAZrWY@linutronix.de/ Fixes: a55ebd4 ("counter: add IRQ or GPIO based counter") Signed-off-by: Alexander Sverdlin <alexander.sverdlin@siemens.com> Reviewed-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de> Link: https://lore.kernel.org/r/20251118083603.778626-1-alexander.sverdlin@siemens.com Signed-off-by: William Breathitt Gray <wbg@kernel.org>
teawater
pushed a commit
that referenced
this pull request
Jan 16, 2026
When forward-porting Rust Binder to 6.18, I neglected to take commit fb56fdf ("mm/list_lru: split the lock to per-cgroup scope") into account, and apparently I did not end up running the shrinker callback when I sanity tested the driver before submission. This leads to crashes like the following: ============================================ WARNING: possible recursive locking detected 6.18.0-mainline-maybe-dirty #1 Tainted: G IO -------------------------------------------- kswapd0/68 is trying to acquire lock: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: lock_list_lru_of_memcg+0x128/0x230 but task is already holding lock: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(&l->lock); lock(&l->lock); *** DEADLOCK *** May be due to missing lock nesting notation 3 locks held by kswapd0/68: #0: ffffffff90d2e260 (fs_reclaim){+.+.}-{0:0}, at: kswapd+0x597/0x1160 #1: ffff956000fa18b0 (&l->lock){+.+.}-{2:2}, at: rust_helper_spin_lock+0xd/0x20 #2: ffffffff90cf3680 (rcu_read_lock){....}-{1:2}, at: lock_list_lru_of_memcg+0x2d/0x230 To fix this, remove the spin_lock() call from rust_shrink_free_page(). Cc: stable <stable@kernel.org> Fixes: eafedbc ("rust_binder: add Rust Binder driver") Signed-off-by: Alice Ryhl <aliceryhl@google.com> Link: https://patch.msgid.link/20251202-binder-shrink-unspin-v1-1-263efb9ad625@google.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Thanks for asking me to work on this. I will get started on it and keep this PR's description up to date as I form a plan and make progress.
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