CVE-2022-50530 (GCVE-0-2022-50530)
Vulnerability from cvelistv5
Published
2025-10-07 15:19
Modified
2025-10-07 15:19
Severity ?
VLAI Severity ?
EPSS score ?
Summary
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
Impacted products
{
"containers": {
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"affected": [
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"product": "Linux",
"programFiles": [
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],
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"vendor": "Linux",
"versions": [
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"status": "affected",
"version": "5.16"
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{
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"version": "6.0.6",
"versionType": "semver"
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{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.1",
"versionType": "original_commit_for_fix"
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]
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],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
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"versionEndExcluding": "6.0.6",
"versionStartIncluding": "5.16",
"vulnerable": true
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{
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"descriptions": [
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"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping()\n\nOur syzkaller report a null pointer dereference, root cause is\nfollowing:\n\n__blk_mq_alloc_map_and_rqs\n set-\u003etags[hctx_idx] = blk_mq_alloc_map_and_rqs\n blk_mq_alloc_map_and_rqs\n blk_mq_alloc_rqs\n // failed due to oom\n alloc_pages_node\n // set-\u003etags[hctx_idx] is still NULL\n blk_mq_free_rqs\n drv_tags = set-\u003etags[hctx_idx];\n // null pointer dereference is triggered\n blk_mq_clear_rq_mapping(drv_tags, ...)\n\nThis is because commit 63064be150e4 (\"blk-mq:\nAdd blk_mq_alloc_map_and_rqs()\") merged the two steps:\n\n1) set-\u003etags[hctx_idx] = blk_mq_alloc_rq_map()\n2) blk_mq_alloc_rqs(..., set-\u003etags[hctx_idx])\n\ninto one step:\n\nset-\u003etags[hctx_idx] = blk_mq_alloc_map_and_rqs()\n\nSince tags is not initialized yet in this case, fix the problem by\nchecking if tags is NULL pointer in blk_mq_clear_rq_mapping()."
}
],
"providerMetadata": {
"dateUpdated": "2025-10-07T15:19:21.259Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/6a440e6d04431e774dc084abe88c106e2a474c1a"
},
{
"url": "https://git.kernel.org/stable/c/76dd298094f484c6250ebd076fa53287477b2328"
}
],
"title": "blk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping()",
"x_generator": {
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}
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"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
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"cveId": "CVE-2022-50530",
"datePublished": "2025-10-07T15:19:21.259Z",
"dateReserved": "2025-10-07T15:15:38.664Z",
"dateUpdated": "2025-10-07T15:19:21.259Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.1",
"vulnerability-lookup:meta": {
"nvd": "{\"cve\":{\"id\":\"CVE-2022-50530\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2025-10-07T16:15:37.020\",\"lastModified\":\"2025-10-08T19:38:32.610\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nblk-mq: fix null pointer dereference in blk_mq_clear_rq_mapping()\\n\\nOur syzkaller report a null pointer dereference, root cause is\\nfollowing:\\n\\n__blk_mq_alloc_map_and_rqs\\n set-\u003etags[hctx_idx] = blk_mq_alloc_map_and_rqs\\n blk_mq_alloc_map_and_rqs\\n blk_mq_alloc_rqs\\n // failed due to oom\\n alloc_pages_node\\n // set-\u003etags[hctx_idx] is still NULL\\n blk_mq_free_rqs\\n drv_tags = set-\u003etags[hctx_idx];\\n // null pointer dereference is triggered\\n blk_mq_clear_rq_mapping(drv_tags, ...)\\n\\nThis is because commit 63064be150e4 (\\\"blk-mq:\\nAdd blk_mq_alloc_map_and_rqs()\\\") merged the two steps:\\n\\n1) set-\u003etags[hctx_idx] = blk_mq_alloc_rq_map()\\n2) blk_mq_alloc_rqs(..., set-\u003etags[hctx_idx])\\n\\ninto one step:\\n\\nset-\u003etags[hctx_idx] = blk_mq_alloc_map_and_rqs()\\n\\nSince tags is not initialized yet in this case, fix the problem by\\nchecking if tags is NULL pointer in blk_mq_clear_rq_mapping().\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/6a440e6d04431e774dc084abe88c106e2a474c1a\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/76dd298094f484c6250ebd076fa53287477b2328\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
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