{"cve":"CVE-2022-50530","nvd":{"published":"2025-10-07T16:15:37.020","modified":"2026-06-17T05:23:44.040","status":"Analyzed","description":"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->tags[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->tags[hctx_idx] is still NULL\n    blk_mq_free_rqs\n     drv_tags = set->tags[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->tags[hctx_idx] = blk_mq_alloc_rq_map()\n2) blk_mq_alloc_rqs(..., set->tags[hctx_idx])\n\ninto one step:\n\nset->tags[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().","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H","score":5.5},"cwes":["CWE-476"],"references":["https://git.kernel.org/stable/c/6a440e6d04431e774dc084abe88c106e2a474c1a","https://git.kernel.org/stable/c/76dd298094f484c6250ebd076fa53287477b2328"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:11:26.888974865+00:00"},"epss":{"cve":"CVE-2022-50530","score":0.0014,"percentile":0.0333,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}