CVE-2022-50839 jbd2: fix potential buffer head reference count leak
A reference count leak in the Linux kernel jbd2 subsystem can lead to memory exhaustion and denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2022-50839?
CVE-2022-50839 is a memory corruption vulnerability in Linux, published on 30 Dec 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:
jbd2: fix potential buffer head reference count leak
As in 'jbd2_fc_wait_bufs' if buffer isn't uptodate, will return -EIO without update 'journal->j_fc_off'. But 'jbd2_fc_release_bufs' will release buffer head from ‘j_fc_off - 1’ if 'bh' is NULL will terminal release which will lead to buffer head buffer head reference count leak. To solve above issue, update 'journal->j_fc_off' before return -EIO.
Which versions are affected by CVE-2022-50839?
How do I fix CVE-2022-50839?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2022-50839 being exploited?
There is no known exploitation of CVE-2022-50839 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2022-50839, GHSA-mjvq-c742-r5cx, UBUNTU-CVE-2022-50839.