In the Linux kernel, the following vulnerability has been resolved:
blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping()
Our syzkaller report a null pointer dereference, root cause is
following:
__blk_mq_alloc_map_and_rqs
set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs
blk_mq_alloc_map_and_rqs
blk_mq_alloc_rqs
// failed due to oom
alloc_pages_node
// set->tags[hctx_idx] is still NULL
blk_mq_free_rqs
drv_tags = set->tags[hctx_idx];
// null pointer dereference is triggered
blk_mq_clear_rq_mapping(drv_tags, ...)
This is because commit 63064be150e4 ("blk-mq:
Add blk_mq_alloc_map_and_rqs()") merged the two steps:
1) set->tags[hctx_idx] = blk_mq_alloc_rq_map()
2) blk_mq_alloc_rqs(..., set->tags[hctx_idx])
into one step:
set->tags[hctx_idx] = blk_mq_alloc_map_and_rqs()
Since tags is not initialized yet in this case, fix the problem by
checking if tags is NULL pointer in blk_mq_clear_rq_mapping().
References
Configurations
Configuration 1 (hide)
|
History
05 Feb 2026, 15:17
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/6a440e6d04431e774dc084abe88c106e2a474c1a - Patch | |
| References | () https://git.kernel.org/stable/c/76dd298094f484c6250ebd076fa53287477b2328 - Patch | |
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 5.5 |
| CWE | CWE-476 | |
| CPE | cpe:2.3:o:linux:linux_kernel:6.1:rc1:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* |
|
| First Time |
Linux
Linux linux Kernel |
07 Oct 2025, 16:15
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2025-10-07 16:15
Updated : 2026-02-05 15:17
NVD link : CVE-2022-50530
Mitre link : CVE-2022-50530
CVE.ORG link : CVE-2022-50530
JSON object : View
Products Affected
linux
- linux_kernel
CWE
CWE-476
NULL Pointer Dereference