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Fencer Vulns
high 7.8

CVE-2024-53166 json

block, bfq: fix bfqq uaf in bfq_limit_depth()

published 2024-12-27 22 mo ago modified 2026-10-15 25 d ago also EUVD-2024-51838

cvss
7.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 17%
public exploits
0
none known

Summary

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

block, bfq: fix bfqq uaf in bfq_limit_depth()

Set new allocated bfqq to bic or remove freed bfqq from bic are both protected by bfqd->lock, however bfq_limit_depth() is deferencing bfqq from bic without the lock, this can lead to UAF if the io_context is shared by multiple tasks.

For example, test bfq with io_uring can trigger following UAF in v6.6:

================================================================== BUG: KASAN: slab-use-after-free in bfqq_group+0x15/0x50

Call Trace: <TASK> dump_stack_lvl+0x47/0x80 print_address_description.constprop.0+0x66/0x300 print_report+0x3e/0x70 kasan_report+0xb4/0xf0 bfqq_group+0x15/0x50 bfqq_request_over_limit+0x130/0x9a0 bfq_limit_depth+0x1b5/0x480 __blk_mq_alloc_requests+0x2b5/0xa00 blk_mq_get_new_requests+0x11d/0x1d0 blk_mq_submit_bio+0x286/0xb00 submit_bio_noacct_nocheck+0x331/0x400 __block_write_full_folio+0x3d0/0x640 writepage_cb+0x3b/0xc0 write_cache_pages+0x254/0x6c0 write_cache_pages+0x254/0x6c0 do_writepages+0x192/0x310 filemap_fdatawrite_wbc+0x95/0xc0 __filemap_fdatawrite_range+0x99/0xd0 filemap_write_and_wait_range.part.0+0x4d/0xa0 blkdev_read_iter+0xef/0x1e0 io_read+0x1b6/0x8a0 io_issue_sqe+0x87/0x300 io_wq_submit_work+0xeb/0x390 io_worker_handle_work+0x24d/0x550 io_wq_worker+0x27f/0x6c0 ret_from_fork_asm+0x1b/0x30 </TASK>

Allocated by task 808602: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 __kasan_slab_alloc+0x83/0x90 kmem_cache_alloc_node+0x1b1/0x6d0 bfq_get_queue+0x138/0xfa0 bfq_get_bfqq_handle_split+0xe3/0x2c0 bfq_init_rq+0x196/0xbb0 bfq_insert_request.isra.0+0xb5/0x480 bfq_insert_requests+0x156/0x180 blk_mq_insert_request+0x15d/0x440 blk_mq_submit_bio+0x8a4/0xb00 submit_bio_noacct_nocheck+0x331/0x400 __blkdev_direct_IO_async+0x2dd/0x330 blkdev_write_iter+0x39a/0x450 io_write+0x22a/0x840 io_issue_sqe+0x87/0x300 io_wq_submit_work+0xeb/0x390 io_worker_handle_work+0x24d/0x550 io_wq_worker+0x27f/0x6c0 ret_from_fork+0x2d/0x50 ret_from_fork_asm+0x1b/0x30

Freed by task 808589: kasan_save_stack+0x1e/0x40 kasan_set_track+0x21/0x30 kasan_save_free_info+0x27/0x40 __kasan_slab_free+0x126/0x1b0 kmem_cache_free+0x10c/0x750 bfq_put_queue+0x2dd/0x770 __bfq_insert_request.isra.0+0x155/0x7a0 bfq_insert_request.isra.0+0x122/0x480 bfq_insert_requests+0x156/0x180 blk_mq_dispatch_plug_list+0x528/0x7e0 blk_mq_flush_plug_list.part.0+0xe5/0x590 __blk_flush_plug+0x3b/0x90 blk_finish_plug+0x40/0x60 do_writepages+0x19d/0x310 filemap_fdatawrite_wbc+0x95/0xc0 __filemap_fdatawrite_range+0x99/0xd0 filemap_write_and_wait_range.part.0+0x4d/0xa0 blkdev_read_iter+0xef/0x1e0 io_read+0x1b6/0x8a0 io_issue_sqe+0x87/0x300 io_wq_submit_work+0xeb/0x390 io_worker_handle_work+0x24d/0x550 io_wq_worker+0x27f/0x6c0 ret_from_fork+0x2d/0x50 ret_from_fork_asm+0x1b/0x30

Fix the problem by protecting bic_to_bfqq() with bfqd->lock.

Patch / fix

  • Linux Linux 6.1.130, 6.6.64, 6.11.11, 6.12.2, 6.13
  • linux Debian 12 6.1.133-1
  • linux Debian 14, Debian 13 6.12.3-1

debian advisories DEBIAN-CVE-2024-53166

  • linux Ubuntu 24.04 LTS 6.8.0-58.60
  • linux-aws Ubuntu 24.04 LTS 6.8.0-1027.29
  • linux-gcp Ubuntu 24.04 LTS 6.8.0-1028.30
  • linux-gke Ubuntu 24.04 LTS 6.8.0-1023.27
  • linux-ibm Ubuntu 24.04 LTS 6.8.0-1024.24
  • linux-azure Ubuntu 24.04 LTS 6.8.0-1027.32
  • linux-gkeop Ubuntu 24.04 LTS 6.8.0-1010.12
  • linux-raspi Ubuntu 24.04 LTS 6.8.0-1028.32

ubuntu advisories UBUNTU-CVE-2024-53166

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • kernel RHEL 9 5.14.0-570.12.1.el9_6
  • rv RHEL 9 5.14.0-570.12.1.el9_6
  • perf RHEL 9 5.14.0-570.12.1.el9_6
  • rtla RHEL 9 5.14.0-570.12.1.el9_6
  • libperf RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-rt RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-64k RHEL 9 5.14.0-570.12.1.el9_6
  • kernel-core RHEL 9 5.14.0-570.12.1.el9_6

red hat advisories RHSA-2025:6966

  • kernel-livepatch-MICRO-6-0_Update_4 Linux Micro 6.1, Linux Micro 6.0 6-1.2
  • kernel-livepatch-MICRO-6-0_Update_2 Linux Micro 6.1, Linux Micro 6.0 8-1.1
  • kernel-livepatch-MICRO-6-0_Update_3 Linux Micro 6.0 8-1.2
  • kernel-livepatch-MICRO-6-0-RT_Update_2 Linux Micro 6.1, Linux Micro 6.0 8-1.1
  • kernel-livepatch-MICRO-6-0-RT_Update_3 Linux Micro 6.0 8-1.2
  • kernel-livepatch-MICRO-6-0-RT_Update_4 Linux Micro 6.1, Linux Micro 6.0 5-1.1
  • kernel-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1
  • kernel-source-rt Linux Micro 6.1, Linux Micro 6.0 6.4.0-25.1

suse advisories SUSE-SU-2025:20527-1SUSE-SU-2025:20541-1SUSE-SU-2025:20525-1SUSE-SU-2025:20526-1SUSE-SU-2025:20540-1SUSE-SU-2025:20517-1

  • kernel Azure Linux 3.0 6.6.64.2-1

azure linux advisories AZL-55706

Azure Linux vulnerability data, Copyright (c) Microsoft Corporation, from https://github.com/microsoft/AzureLinuxVulnerabilityData via OSV, under the MIT licence; changed: normalised to fixed package versions per release. MIT

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-2024-53166 updated cvss 6.7

kernel: block, bfq: fix bfqq uaf in bfq_limit_depth()

  • Red Hat Enterprise Linux AppStream (v. 9) rv 5.14.0-570.12.1.el9_6, perf 5.14.0-570.12.1.el9_6, rtla 5.14.0-570.12.1.el9_6, python3-perf 5.14.0-570.12.1.el9_6, kernel-devel-matched 5.14.0-570.12.1.el9_6, kernel-64k-devel-matched 5.14.0-570.12.1.el9_6, +7 more Red Hat Enterprise Linux BaseOS (v. 9) kernel 5.14.0-570.12.1.el9_6, kernel-64k 5.14.0-570.12.1.el9_6, kernel-core 5.14.0-570.12.1.el9_6, kernel-tools 5.14.0-570.12.1.el9_6, kernel-modules 5.14.0-570.12.1.el9_6, kernel-64k-core 5.14.0-570.12.1.el9_6, +27 more Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) libperf 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-s390x 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-x86_64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-aarch64 5.14.0-570.12.1.el9_6, kernel-debuginfo-common-ppc64le 5.14.0-570.12.1.el9_6 Red Hat Enterprise Linux Real Time (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-64k 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-64k-core 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +14 more Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt 5.14.0-570.12.1.el9_6, kernel-rt-kvm 5.14.0-570.12.1.el9_6, kernel-rt-core 5.14.0-570.12.1.el9_6, kernel-rt-modules 5.14.0-570.12.1.el9_6, kernel-rt-debug-kvm 5.14.0-570.12.1.el9_6, kernel-rt-debug-core 5.14.0-570.12.1.el9_6, +6 more
    fixed: vendor fix RHSA-2025:6966
  • Red Hat Enterprise Linux 6 perf, kernel, python-perf, kernel-kdump, kernel-firmware, kernel-bootwrapper, +1 more 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
    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 ICSA-26-295-16 updated cvss 7.8

Siemens SIMATIC S7-1500 TM MFP

  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

cisa ICSA-25-162-05 updated cvss 7.8

Siemens SIMATIC S7-1500 CPU family

  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP (6ES7518-4AX00-1AC0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AB0) >= 3.1.5 Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP (6ES7518-4FX00-1AC0) >= 3.1.5 Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP (6AG1518-4AX00-4AC0) >= 3.1.5
    affected: mitigation, no fix available

Facts from CISA's republication of the vendor's own advisory (CSAF); the linked advisory is the authoritative source. CISA notification · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
20 mo ago

Exploit prediction

0.26% chance of exploitation in the next 30 days, higher than 17% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
CISA ADP 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 3.1 7.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected products

  • Linux Linux
  • Siemens SIMATIC S7-1500 CPU 1518-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP
  • Siemens SIMATIC S7-1500 TM MFP - GNU/Linux subsystem
  • Siemens SIPLUS S7-1500 CPU 1518-4 PN/DP MFP

Classification

Weakness
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.