CVE-2025-68769 f2fs: fix return value of f2fs_recover_fsync_data()
A local attacker can cause a kernel panic in the Linux f2fs filesystem by mounting a crafted image with specific read-only recovery options.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-68769?
CVE-2025-68769 is a denial of service vulnerability in Linux, published on 13 Jan 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix return value of f2fs_recover_fsync_data()
With below scripts, it will trigger panic in f2fs:
mkfs.f2fs -f /dev/vdd mount /dev/vdd /mnt/f2fs touch /mnt/f2fs/foo sync echo 111 >> /mnt/f2fs/foo f2fs_io fsync /mnt/f2fs/foo f2fs_io shutdown 2 /mnt/f2fs umount /mnt/f2fs mount -o ro,norecovery /dev/vdd /mnt/f2fs or mount -o ro,disable_roll_forward /dev/vdd /mnt/f2fs
F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 0 F2FS-fs (vdd): Mounted with checkpoint version = 7f5c361f F2FS-fs (vdd): Stopped filesystem due to reason: 0 F2FS-fs (vdd): f2fs_recover_fsync_data: recovery fsync data, check_only: 1 Filesystem f2fs get_tree() didn't set fc->root, returned 1 ------------[ cut here ]------------ kernel BUG at fs/super.c:1761! Oops: invalid opcode: 0000 [#1] SMP PTI CPU: 3 UID: 0 PID: 722 Comm: mount Not tainted 6.18.0-rc2+ #721 PREEMPT(voluntary) Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.16.3-debian-1.16.3-2 04/01/2014 RIP: 0010:vfs_get_tree.cold+0x18/0x1a Call Trace: <TASK> fc_mount+0x13/0xa0 path_mount+0x34e/0xc50 __x64_sys_mount+0x121/0x150 do_syscall_64+0x84/0x800 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7fa6cc126cfe
The root cause is we missed to handle error number returned from f2fs_recover_fsync_data() when mounting image w/ ro,norecovery or ro,disable_roll_forward mount option, result in returning a positive error number to vfs_get_tree(), fix it.
Which versions are affected by CVE-2025-68769?
How do I fix CVE-2025-68769?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-68769 being exploited?
There is no known exploitation of CVE-2025-68769 in the wild and no public exploit code.
Sources
Also known as AZL-74396, BELL-CVE-2025-68769, DEBIAN-CVE-2025-68769, GHSA-26j2-hmhf-7cc5, ROOT-OS-DEBIAN-11-CVE-2025-68769, ROOT-OS-DEBIAN-12-CVE-2025-68769 and 4 more.