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

f2fs: fix to cover read extent cache access with lock

syzbot reports a f2fs bug as below:

BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097

CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024
Call Trace:
<TASK>
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114
print_address_description mm/kasan/report.c:377 [inline]
print_report+0x169/0x550 mm/kasan/report.c:488
kasan_report+0x143/0x180 mm/kasan/report.c:601
sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46
do_read_inode fs/f2fs/inode.c:509 [inline]
f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560
f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237
generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413
exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444
exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584
do_handle_to_path fs/fhandle.c:155 [inline]
handle_to_path fs/fhandle.c:210 [inline]
do_handle_open+0x495/0x650 fs/fhandle.c:226
do_syscall_x64 arch/x86/entry/common.c:52 [inline]
do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83
entry_SYSCALL_64_after_hwframe+0x77/0x7f

We missed to cover sanity_check_extent_cache() w/ extent cache lock,
so, below race case may happen, result in use after free issue.

- f2fs_iget
- do_read_inode
- f2fs_init_read_extent_tree
: add largest extent entry in to cache
- shrink
- f2fs_shrink_read_extent_tree
- __shrink_extent_tree
- __detach_extent_node
: drop largest extent entry
- sanity_check_extent_cache
: access et->largest w/o lock

let's refactor sanity_check_extent_cache() to avoid extent cache access
and call it before f2fs_init_read_extent_tree() to fix this issue.
Published: 2024-08-26
Score: 7.8 High
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
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Remediation

No vendor fix or workaround currently provided.

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Advisories
Source ID Title
Ubuntu USN Ubuntu USN USN-7154-1 Linux kernel vulnerabilities
Ubuntu USN Ubuntu USN USN-7155-1 Linux kernel (NVIDIA) vulnerabilities
Ubuntu USN Ubuntu USN USN-7156-1 Linux kernel (GKE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7154-2 Linux kernel (HWE) vulnerabilities
Ubuntu USN Ubuntu USN USN-7196-1 Linux kernel (Azure) vulnerabilities
History

Wed, 23 Oct 2024 15:00:00 +0000

Type Values Removed Values Added
Metrics threat_severity

Low

threat_severity

Important


Thu, 12 Sep 2024 21:15:00 +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'}


Wed, 11 Sep 2024 13:30:00 +0000

Type Values Removed Values Added
Metrics ssvc

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


Tue, 27 Aug 2024 19:00:00 +0000

Type Values Removed Values Added
Metrics threat_severity

Moderate

threat_severity

Low


Tue, 27 Aug 2024 15:30:00 +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

Moderate


Mon, 26 Aug 2024 11:30:00 +0000

Type Values Removed Values Added
Description In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to cover read extent cache access with lock syzbot reports a f2fs bug as below: BUG: KASAN: slab-use-after-free in sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 Read of size 4 at addr ffff8880739ab220 by task syz-executor200/5097 CPU: 0 PID: 5097 Comm: syz-executor200 Not tainted 6.9.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/27/2024 Call Trace: <TASK> __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_address_description mm/kasan/report.c:377 [inline] print_report+0x169/0x550 mm/kasan/report.c:488 kasan_report+0x143/0x180 mm/kasan/report.c:601 sanity_check_extent_cache+0x370/0x410 fs/f2fs/extent_cache.c:46 do_read_inode fs/f2fs/inode.c:509 [inline] f2fs_iget+0x33e1/0x46e0 fs/f2fs/inode.c:560 f2fs_nfs_get_inode+0x74/0x100 fs/f2fs/super.c:3237 generic_fh_to_dentry+0x9f/0xf0 fs/libfs.c:1413 exportfs_decode_fh_raw+0x152/0x5f0 fs/exportfs/expfs.c:444 exportfs_decode_fh+0x3c/0x80 fs/exportfs/expfs.c:584 do_handle_to_path fs/fhandle.c:155 [inline] handle_to_path fs/fhandle.c:210 [inline] do_handle_open+0x495/0x650 fs/fhandle.c:226 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf5/0x240 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f We missed to cover sanity_check_extent_cache() w/ extent cache lock, so, below race case may happen, result in use after free issue. - f2fs_iget - do_read_inode - f2fs_init_read_extent_tree : add largest extent entry in to cache - shrink - f2fs_shrink_read_extent_tree - __shrink_extent_tree - __detach_extent_node : drop largest extent entry - sanity_check_extent_cache : access et->largest w/o lock let's refactor sanity_check_extent_cache() to avoid extent cache access and call it before f2fs_init_read_extent_tree() to fix this issue.
Title f2fs: fix to cover read extent cache access with lock
References

Subscriptions

Linux Linux Kernel
cve-icon MITRE

Status: PUBLISHED

Assigner: Linux

Published:

Updated: 2026-05-11T20:32:26.189Z

Reserved: 2024-08-21T05:34:56.665Z

Link: CVE-2024-44941

cve-icon Vulnrichment

Updated: 2024-09-11T12:42:13.936Z

cve-icon NVD

Status : Analyzed

Published: 2024-08-26T12:15:06.107

Modified: 2026-04-01T18:09:32.867

Link: CVE-2024-44941

cve-icon Redhat

Severity : Important

Publid Date: 2024-08-26T00:00:00Z

Links: CVE-2024-44941 - Bugzilla

cve-icon OpenCVE Enrichment

No data.

Weaknesses