{"cve":"CVE-2022-49901","nvd":{"published":"2025-05-01T15:16:15.167","modified":"2026-06-17T05:19:27.923","status":"Modified","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nblk-mq: Fix kmemleak in blk_mq_init_allocated_queue\n\nThere is a kmemleak caused by modprobe null_blk.ko\n\nunreferenced object 0xffff8881acb1f000 (size 1024):\n  comm \"modprobe\", pid 836, jiffies 4294971190 (age 27.068s)\n  hex dump (first 32 bytes):\n    00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00  .....N..........\n    ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff  .........S......\n  backtrace:\n    [<000000004a10c249>] kmalloc_node_trace+0x22/0x60\n    [<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350\n    [<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0\n    [<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440\n    [<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0\n    [<00000000d10c98c3>] 0xffffffffc450d69d\n    [<00000000b9299f48>] 0xffffffffc4538392\n    [<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0\n    [<00000000b389383b>] do_init_module+0x1a4/0x680\n    [<0000000087cf3542>] load_module+0x6249/0x7110\n    [<00000000beba61b8>] __do_sys_finit_module+0x140/0x200\n    [<00000000fdcfff51>] do_syscall_64+0x35/0x80\n    [<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0\n\nThat is because q->ma_ops is set to NULL before blk_release_queue is\ncalled.\n\nblk_mq_init_queue_data\n  blk_mq_init_allocated_queue\n    blk_mq_realloc_hw_ctxs\n      for (i = 0; i < set->nr_hw_queues; i++) {\n        old_hctx = xa_load(&q->hctx_table, i);\n        if (!blk_mq_alloc_and_init_hctx(.., i, ..))\t\t[1]\n          if (!old_hctx)\n\t    break;\n\n      xa_for_each_start(&q->hctx_table, j, hctx, j)\n        blk_mq_exit_hctx(q, set, hctx, j); \t\t\t[2]\n\n    if (!q->nr_hw_queues)\t\t\t\t\t[3]\n      goto err_hctxs;\n\n  err_exit:\n      q->mq_ops = NULL;\t\t\t  \t\t\t[4]\n\n  blk_put_queue\n    blk_release_queue\n      if (queue_is_mq(q))\t\t\t\t\t[5]\n        blk_mq_release(q);\n\n[1]: blk_mq_alloc_and_init_hctx failed at i != 0.\n[2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and\nwill be cleaned up in blk_mq_release.\n[3]: q->nr_hw_queues is 0.\n[4]: Set q->mq_ops to NULL.\n[5]: queue_is_mq returns false due to [4]. And blk_mq_release\nwill not be called. The hctxs in q->unused_hctx_list are leaked.\n\nTo fix it, call blk_release_queue in exception path.","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-401"],"references":["https://git.kernel.org/stable/c/2dc97e15a54b7bdf457848aa8c663c98a24e58a6","https://git.kernel.org/stable/c/943f45b9399ed8b2b5190cbc797995edaa97f58f"],"products":["linux:linux_kernel"],"source":"nvd","synced_at":"2026-10-19T22:01:22.920403922+00:00"},"epss":{"cve":"CVE-2022-49901","score":0.00172,"percentile":0.06521,"date":"2026-11-01"},"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."]}