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Fencer Vulns
medium 5.5

CVE-2022-49901 json

blk-mq: Fix kmemleak in blk_mq_init_allocated_queue

published 2025-05-01 18 mo ago modified 2026-06-17 4 mo ago also EUVD-2025-12864

cvss
5.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 6%
public exploits
0
none known

Summary

In the Linux kernel, the following vulnerability has been resolved:

blk-mq: Fix kmemleak in blk_mq_init_allocated_queue

There is a kmemleak caused by modprobe null_blk.ko

unreferenced object 0xffff8881acb1f000 (size 1024): comm "modprobe", pid 836, jiffies 4294971190 (age 27.068s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff 00 53 99 9e ff ff ff ff .........S...... backtrace: [<000000004a10c249>] kmalloc_node_trace+0x22/0x60 [<00000000648f7950>] blk_mq_alloc_and_init_hctx+0x289/0x350 [<00000000af06de0e>] blk_mq_realloc_hw_ctxs+0x2fe/0x3d0 [<00000000e00c1872>] blk_mq_init_allocated_queue+0x48c/0x1440 [<00000000d16b4e68>] __blk_mq_alloc_disk+0xc8/0x1c0 [<00000000d10c98c3>] 0xffffffffc450d69d [<00000000b9299f48>] 0xffffffffc4538392 [<0000000061c39ed6>] do_one_initcall+0xd0/0x4f0 [<00000000b389383b>] do_init_module+0x1a4/0x680 [<0000000087cf3542>] load_module+0x6249/0x7110 [<00000000beba61b8>] __do_sys_finit_module+0x140/0x200 [<00000000fdcfff51>] do_syscall_64+0x35/0x80 [<000000003c0f1f71>] entry_SYSCALL_64_after_hwframe+0x46/0xb0

That is because q->ma_ops is set to NULL before blk_release_queue is called.

blk_mq_init_queue_data blk_mq_init_allocated_queue blk_mq_realloc_hw_ctxs for (i = 0; i < set->nr_hw_queues; i++) { old_hctx = xa_load(&q->hctx_table, i); if (!blk_mq_alloc_and_init_hctx(.., i, ..)) [1] if (!old_hctx) break;

xa_for_each_start(&q->hctx_table, j, hctx, j) blk_mq_exit_hctx(q, set, hctx, j); [2]

if (!q->nr_hw_queues) [3] goto err_hctxs;

err_exit: q->mq_ops = NULL; [4]

blk_put_queue blk_release_queue if (queue_is_mq(q)) [5] blk_mq_release(q);

[1]: blk_mq_alloc_and_init_hctx failed at i != 0. [2]: The hctxs allocated by [1] are moved to q->unused_hctx_list and will be cleaned up in blk_mq_release. [3]: q->nr_hw_queues is 0. [4]: Set q->mq_ops to NULL. [5]: queue_is_mq returns false due to [4]. And blk_mq_release will not be called. The hctxs in q->unused_hctx_list are leaked.

To fix it, call blk_release_queue in exception path.

Patch / fix

  • Linux Linux 6.0.8, 6.1
  • linux Debian 14, Debian 13, Debian 12 6.0.8-1

debian advisories DEBIAN-CVE-2022-49901

  • kernel-64kb SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS, SLE High Performance Computing 15 SP5-ESPOS 5.14.21-150500.55.110.1
  • kernel-syms SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.110.1
  • kernel-source SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.110.1
  • kernel-default SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +3 more 5.14.21-150500.55.110.1
  • kernel-obs-build SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE High Performance Computing 15 SP5-LTSS +1 more 5.14.21-150500.55.110.1
  • kernel-default-base SLES for SAP 15 SP5, SLES 15 SP5-LTSS, SLE Micro 5.5 +2 more 5.14.21-150500.55.110.1.150500.6.51.3
  • kernel-rt SLE Micro 5.5 5.14.21-150500.13.97.1
  • kernel-source-rt SLE Micro 5.5 5.14.21-150500.13.97.1

suse advisories SUSE-SU-2025:02173-1SUSE-SU-2025:01966-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2022-49901 updated cvss 4.1

kernel: blk-mq: Fix kmemleak in blk_mq_init_allocated_queue

  • Red Hat Enterprise Linux 7 perf, kernel, bpftool, kernel-rt, python-perf, kernel-kdump, +8 more Red Hat Enterprise Linux 8 perf, kernel, bpftool, kernel-rt, kernel-core, kernel-tools, +29 more
    affected: no fix planned “Out of support scope”
  • Red Hat Enterprise Linux 9 rv, perf, rtla, kernel, bpftool, libperf, +83 more
    affected: no fix available “Fix deferred”
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more Red Hat Enterprise Linux 10 kernel
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
partial
Assessed
13 mo ago

Exploit prediction

0.17% chance of exploitation in the next 30 days, higher than 6% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CISA ADP 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
CNA 3.1 5.5 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

Affected products

  • Linux Linux

Classification

Weakness
  • CWE-401 Missing Release of Memory after Effective Lifetime
Technology feeds

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.