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VulnerabilityPublished Updated

CVE-2024-47689: Linux kernel · f2fs: fix to don't set SB_RDONLY in f2fs_handle_critical_error()

Affects Linux kernelSource GCVE Database

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Not known to be exploited · CVSS 5.3 Medium · fixed in 6.8.0-1023.25~22.04.1 : update Linux kernel when convenient.

Data as of 12 Nov 2026, 19:06 UTC

CVSS 3.1 base score
5.3Medium
How severe the flaw is on the 0–10 CVSS scale.
Patch
Available – fixed in 6.8.0-1023.25~22.04.1, 6.8.0-1025.30~22.04.1, 6.8.0-1024.26~22.04.1 +29
CVSS:3.1/AV:N/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H

Exploitation evidence

  1. Disclosed: evidence found.

    CVE published 21 Oct 2024

  2. Detectable: no evidence on record.

    No public nuclei template indexed

  3. Weaponized: no evidence on record.

    No public exploit code indexed in Metasploit or Exploit-DB

  4. Exploited in the wild: no evidence on record.

    Not in CISA KEV and no source reports exploitation

  5. Observed by OffSeq 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.

Affected software

ProductAffectedFixed in
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-54.56
Fixed in
  • 6.8.0-54.56
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1023.25
Fixed in
  • 6.8.0-1023.25
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1025.30
Fixed in
  • 6.8.0-1025.30
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threatsAffected
  • <6.11.0-1012.12~24.04.1
Fixed in
  • 6.11.0-1012.12~24.04.1
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1014.15
Fixed in
  • 6.8.0-1014.15
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threatsAffected
  • <6.8.0-1024.26
Fixed in
  • 6.8.0-1024.26

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 don't set SB_RDONLY in f2fs_handle_critical_error() syzbot reports a f2fs bug as below: ------------[ cut here ]------------ WARNING: CPU: 1 PID: 58 at kernel/rcu/sync.c:177 rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177 CPU: 1 UID: 0 PID: 58 Comm: kworker/1:2 Not tainted 6.10.0-syzkaller-12562-g1722389b0d86 #0 Workqueue: events destroy_super_work RIP: 0010:rcu_sync_dtor+0xcd/0x180 kernel/rcu/sync.c:177 Call Trace: percpu_free_rwsem+0x41/0x80 kernel/locking/percpu-rwsem.c:42 destroy_super_work+0xec/0x130 fs/super.c:282 process_one_work kernel/workqueue.c:3231 [inline] process_scheduled_works+0xa2c/0x1830 kernel/workqueue.c:3312 worker_thread+0x86d/0xd40 kernel/workqueue.c:3390 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 As Christian Brauner pointed out [1]: the root cause is f2fs sets SB_RDONLY flag in internal function, rather than setting the flag covered w/ sb->s_umount semaphore via remount procedure, then below race condition causes this bug: - freeze_super() - sb_wait_write(sb, SB_FREEZE_WRITE) - sb_wait_write(sb, SB_FREEZE_PAGEFAULT) - sb_wait_write(sb, SB_FREEZE_FS) - f2fs_handle_critical_error - sb->s_flags |= SB_RDONLY - thaw_super - thaw_super_locked - sb_rdonly() is true, so it skips sb_freeze_unlock(sb, SB_FREEZE_FS) - deactivate_locked_super Since f2fs has almost the same logic as ext4 [2] when handling critical error in filesystem if it mounts w/ errors=remount-ro option: - set CP_ERROR_FLAG flag which indicates filesystem is stopped - record errors to superblock - set SB_RDONLY falg Once we set CP_ERROR_FLAG flag, all writable interfaces can detect the flag and stop any further updates on filesystem. So, it is safe to not set SB_RDONLY flag, let's remove the logic and keep in line w/ ext4 [3]. [1] https://lore.kernel.org/all/20240729-himbeeren-funknetz-96e62f9c7aee@brauner [2] https://lore.kernel.org/all/20240729132721.hxih6ehigadqf7wx@quack3 [3] https://lore.kernel.org/linux-ext4/20240805201241.27286-1-jack@suse.cz

References

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