Fix null pointer dereferences when allocation fails

src/readstat_writer.c

@@ -28,6 +28,7 @@ static int readstat_compare_string_refs(const void *elem1, const void *elem2) {
 readstat_string_ref_t *readstat_string_ref_init(const char *string) {
     size_t len = strlen(string) + 1;
     readstat_string_ref_t *ref = calloc(1, sizeof(readstat_string_ref_t) + len);
+    if (ref == NULL) return NULL;
     ref->first_o = -1;
     ref->first_v = -1;
     ref->len = len;
@@ -140,6 +141,7 @@ static readstat_error_t readstat_begin_writing_data(readstat_writer_t *writer) {
     }
     writer->row_len = row_len;
     writer->row = malloc(writer->row_len);
+    if (writer->row == NULL) { retval = READSTAT_ERROR_MALLOC; goto cleanup; }
     if (writer->callbacks.begin_data) {
         retval = writer->callbacks.begin_data(writer);
     }

src/sas/readstat_sas7bdat_read.c

@@ -513,6 +513,7 @@ static readstat_error_t sas7bdat_parse_subheader_rdc(const char *subheader, size
     readstat_error_t retval = READSTAT_OK;
     const unsigned char *input = (const unsigned char *)subheader;
     char *buffer = malloc(ctx->row_length);
+    if (buffer == NULL) return READSTAT_ERROR_MALLOC;
     char *output = buffer;
     while (input + 2 <= (const unsigned char *)subheader + len) {
         int i;
@@ -1211,6 +1212,11 @@ readstat_error_t readstat_parse_sas7bdat(readstat_parser_t *parser, const char *
     sas7bdat_ctx_t  *ctx = calloc(1, sizeof(sas7bdat_ctx_t));
     sas_header_info_t  *hinfo = calloc(1, sizeof(sas_header_info_t));
 
+    if (ctx == NULL || hinfo == NULL) {
+        retval = READSTAT_ERROR_MALLOC;
+        goto cleanup;
+    }
+
     ctx->handle = parser->handlers;
     ctx->input_encoding = parser->input_encoding;
     ctx->output_encoding = parser->output_encoding;

src/sas/readstat_xport_read.c

@@ -281,6 +281,7 @@ static readstat_error_t xport_read_obs_header_record(xport_ctx_t *ctx) {
 static readstat_error_t xport_construct_format(char *dst, size_t dst_len,
         const char *src, size_t src_len, int width, int decimals) {
     char *format = malloc(4 * src_len + 1);
+    if (format == NULL) return READSTAT_ERROR_MALLOC;
     readstat_error_t retval = readstat_convert(format, 4 * src_len + 1, src, src_len, NULL);
 
     if (retval != READSTAT_OK) {

src/stata/readstat_dta_read.c

@@ -36,9 +36,14 @@ static readstat_error_t dta_update_progress(dta_ctx_t *ctx) {
 }
 
 static readstat_variable_t *dta_init_variable(dta_ctx_t *ctx, int i, int index_after_skipping,
-        readstat_type_t type, size_t max_len) {
+        readstat_type_t type, size_t max_len, readstat_error_t *out_retval) {
     readstat_variable_t *variable = calloc(1, sizeof(readstat_variable_t));
 
+    if (variable == NULL) {
+        if (out_retval) *out_retval = READSTAT_ERROR_MALLOC;
+        return NULL;
+    }
+
     variable->type = type;
     variable->index = i;
     variable->index_after_skipping = index_after_skipping;
@@ -952,7 +957,9 @@ static readstat_error_t dta_handle_variables(dta_ctx_t *ctx) {
             max_len = 0;
         }
 
-        ctx->variables[i] = dta_init_variable(ctx, i, index_after_skipping, type, max_len);
+        ctx->variables[i] = dta_init_variable(ctx, i, index_after_skipping, type, max_len, &retval);
+        if (ctx->variables[i] == NULL)
+            goto cleanup;
 
         const char *value_labels = NULL;