Description
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.
Published: 2024-12-27
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories
Source ID Title
Debian DLA Debian DLA DLA-4193-1 linux-6.1 security update
Debian DSA Debian DSA DSA-5900-1 linux security update
EUVD EUVD EUVD-2024-51838 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.
Ubuntu USN Ubuntu USN USN-7276-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7277-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7310-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7449-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7449-2 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7450-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7451-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7452-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7453-1 Linux kernel (Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7468-1 Linux kernel (Azure, N-Series) vulnerabilities
Ubuntu USN Ubuntu USN USN-7523-1 Linux kernel (Raspberry Pi Real-time) vulnerabilities
Ubuntu USN Ubuntu USN USN-7524-1 Linux kernel (Raspberry Pi) vulnerabilities
History

Tue, 12 May 2026 13:30:00 +0000

Type Values Removed Values Added
References

Mon, 03 Nov 2025 20:30:00 +0000

Type Values Removed Values Added
References

Wed, 16 Jul 2025 13:45:00 +0000

Type Values Removed Values Added
Metrics epss

{'score': 0.00032}

epss

{'score': 0.00034}


Wed, 14 May 2025 02:30:00 +0000

Type Values Removed Values Added
First Time appeared Redhat
Redhat enterprise Linux
CPEs cpe:/a:redhat:enterprise_linux:9
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux

Fri, 07 Mar 2025 18:15:00 +0000


Thu, 13 Feb 2025 00:30:00 +0000

Type Values Removed Values Added
Metrics threat_severity

Important

threat_severity

Moderate


Mon, 10 Feb 2025 18:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Thu, 16 Jan 2025 17:00:00 +0000

Type Values Removed Values Added
First Time appeared Linux
Linux linux Kernel
Weaknesses CWE-416
CPEs cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*
Vendors & Products Linux
Linux linux Kernel
Metrics cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

cvssV3_1

{'score': 7.8, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H'}


Mon, 30 Dec 2024 01:30:00 +0000

Type Values Removed Values Added
References
Metrics threat_severity

None

cvssV3_1

{'score': 5.5, 'vector': 'CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H'}

threat_severity

Important


Fri, 27 Dec 2024 14:00:00 +0000

Type Values Removed Values Added
Description 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.
Title block, bfq: fix bfqq uaf in bfq_limit_depth()
References

Subscriptions

Linux Linux Kernel
Redhat Enterprise Linux
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-12T12:01:22.566Z

Reserved: 2024-11-19T17:17:25.005Z

Link: CVE-2024-53166

cve-icon Vulnrichment

Updated: 2025-11-03T19:32:00.758Z

cve-icon NVD

Status : Modified

Published: 2024-12-27T14:15:23.703

Modified: 2026-05-12T13:16:22.310

Link: CVE-2024-53166

cve-icon Redhat

Severity : Moderate

Publid Date: 2024-12-27T00:00:00Z

Links: CVE-2024-53166 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses