CVE-2024-47691: Linux kernel · f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.4.0-1153.163~18.04.1 : patch Linux kernel soon.
Data as of 12 Nov 2026, 19:06 UTC
- Patch
- Available – fixed in 5.4.0-1153.163~18.04.1, 5.4.0-1156.163~18.04.1, 5.4.0-1156.165~18.04.1 +82
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 21 Oct 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7301-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7303-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7304-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7303-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7311-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7303-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7384-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7385-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7386-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: f2fs: fix to avoid use-after-free in f2fs_stop_gc_thread() syzbot reports a f2fs bug as below: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:114 print_report+0xe8/0x550 mm/kasan/report.c:491 kasan_report+0x143/0x180 mm/kasan/report.c:601 kasan_check_range+0x282/0x290 mm/kasan/generic.c:189 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:184 [inline] __refcount_inc include/linux/refcount.h:241 [inline] refcount_inc include/linux/refcount.h:258 [inline] get_task_struct include/linux/sched/task.h:118 [inline] kthread_stop+0xca/0x630 kernel/kthread.c:704 f2fs_stop_gc_thread+0x65/0xb0 fs/f2fs/gc.c:210 f2fs_do_shutdown+0x192/0x540 fs/f2fs/file.c:2283 f2fs_ioc_shutdown fs/f2fs/file.c:2325 [inline] __f2fs_ioctl+0x443a/0xbe60 fs/f2fs/file.c:4325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f The root cause is below race condition, it may cause use-after-free issue in sbi->gc_th pointer. - remount - f2fs_remount - f2fs_stop_gc_thread - kfree(gc_th) - f2fs_ioc_shutdown - f2fs_do_shutdown - f2fs_stop_gc_thread - kthread_stop(gc_th->f2fs_gc_task) : sbi->gc_thread = NULL; We will call f2fs_do_shutdown() in two paths: - for f2fs_ioc_shutdown() path, we should grab sb->s_umount semaphore for fixing. - for f2fs_shutdown() path, it's safe since caller has already grabbed sb->s_umount semaphore.
References
- ubuntu.com/security/CVE-2024-47691 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-47691 (opens in a new tab)
- git.kernel.org/linus/c7f114d864ac91515bb07ac271e9824a20f5ed95 (opens in a new tab)
- git.kernel.org/stable/c/fc18e655b62ac6bc9f12f5de0d749b4a3fe1e812 (opens in a new tab)
- git.kernel.org/stable/c/7c339dee7eb0f8e4cadc317c595f898ef04dae30 (opens in a new tab)
- git.kernel.org/stable/c/d79343cd66343709e409d96b2abb139a0a55ce34 (opens in a new tab)
- git.kernel.org/stable/c/c7f114d864ac91515bb07ac271e9824a20f5ed95 (opens in a new tab)
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7301-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7303-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7304-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7303-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7310-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7311-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7303-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7384-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7385-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7386-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7384-2 (opens in a new tab)