CVE-2026-89837 f2fs: fix dentry folio leak in find_in_level
A memory leak in the Linux kernel f2fs filesystem allows local attackers to cause denial of service by exhausting memory resources.
- 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-2026-89837?
CVE-2026-89837 is a memory corruption vulnerability in Linux, published on 16 Sep 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 dentry folio leak in find_in_level
find_in_level() gets a dentry folio with f2fs_find_data_folio() before calling find_in_block(). If find_in_block() returns an error, the function stores the error in res_folio and breaks out of the loop without dropping the dentry folio.
This leaks the folio reference on the find_in_block() error path. Drop the dentry folio before returning the error to the caller.
Which versions are affected by CVE-2026-89837?
How do I fix CVE-2026-89837?
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-2026-89837 being exploited?
There is no known exploitation of CVE-2026-89837 in the wild and no public exploit code.
Sources
Also known as AZL-101168, BELL-CVE-2026-89837, DEBIAN-CVE-2026-89837, GHSA-cwf6-7jp2-62cf, UBUNTU-CVE-2026-89837.