CVE-2022-50567 fs: jfs: fix shift-out-of-bounds in dbAllocAG
A shift-out-of-bounds error in the Linux kernel JFS filesystem allows local attackers to cause a system crash via a crafted filesystem image.
- 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-2022-50567?
CVE-2022-50567 is a high-severity vulnerability in Linux, published on 22 Oct 2025. 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:
fs: jfs: fix shift-out-of-bounds in dbAllocAG
Syzbot found a crash : UBSAN: shift-out-of-bounds in dbAllocAG. The underlying bug is the missing check of bmp->db_agl2size. The field can be greater than 64 and trigger the shift-out-of-bounds.
Fix this bug by adding a check of bmp->db_agl2size in dbMount since this field is used in many following functions. The upper bound for this field is L2MAXL2SIZE - L2MAXAG, thanks for the help of Dave Kleikamp. Note that, for maintenance, I reorganized error handling code of dbMount.
Which versions are affected by CVE-2022-50567?
How do I fix CVE-2022-50567?
Apply the vendor's patch.
Is CVE-2022-50567 being exploited?
There is no known exploitation of CVE-2022-50567 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50567, GHSA-f88f-286j-xf6g, UBUNTU-CVE-2022-50567.