CVE-2022-50753 f2fs: fix to do sanity check on summary info
A use-after-free vulnerability in the Linux kernel's f2fs filesystem allows attackers to cause a denial of service or potentially execute code via a crafted filesystem image.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2022-50753?
CVE-2022-50753 is a high-severity use after free vulnerability in Linux, published on 24 Dec 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
In the Linux kernel, the following vulnerability has been resolved:
f2fs: fix to do sanity check on summary info
As Wenqing Liu reported in bugzilla:
https://bugzilla.kernel.org/show_bug.cgi?id=216456
BUG: KASAN: use-after-free in recover_data+0x63ae/0x6ae0 [f2fs] Read of size 4 at addr ffff8881464dcd80 by task mount/1013
CPU: 3 PID: 1013 Comm: mount Tainted: G W 6.0.0-rc4 #1 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014 Call Trace: dump_stack_lvl+0x45/0x5e print_report.cold+0xf3/0x68d kasan_report+0xa8/0x130 recover_data+0x63ae/0x6ae0 [f2fs] f2fs_recover_fsync_data+0x120d/0x1fc0 [f2fs] f2fs_fill_super+0x4665/0x61e0 [f2fs] mount_bdev+0x2cf/0x3b0 legacy_get_tree+0xed/0x1d0 vfs_get_tree+0x81/0x2b0 path_mount+0x47e/0x19d0 do_mount+0xce/0xf0 __x64_sys_mount+0x12c/0x1a0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x63/0xcd
The root cause is: in fuzzed image, SSA table is corrupted: ofs_in_node is larger than ADDRS_PER_PAGE(), result in out-of-range access on 4k-size page.
- recover_data - do_recover_data - check_index_in_prev_nodes - f2fs_data_blkaddr
This patch adds sanity check on summary info in recovery and GC flow in where the flows rely on them.
After patch: [ 29.310883] F2FS-fs (loop0): Inconsistent ofs_in_node:65286 in summary, ino:0, nid:6, max:1018
Which versions are affected by CVE-2022-50753?
How do I fix CVE-2022-50753?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2022-50753 being exploited?
There is no known exploitation of CVE-2022-50753 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50753, GHSA-83fq-277g-4r9j, UBUNTU-CVE-2022-50753.