CVE-2026-45861 gfs2: Fix slab-use-after-free in qd_put
A use-after-free vulnerability in the Linux kernel's GFS2 filesystem allows attackers to cause denial of service or potentially execute code.
- 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-2026-45861?
CVE-2026-45861 is a high-severity use after free vulnerability in Linux kernel, published on 27 May 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:
gfs2: Fix slab-use-after-free in qd_put
Commit a475c5dd16e5 ("gfs2: Free quota data objects synchronously") started freeing quota data objects during filesystem shutdown instead of putting them back onto the LRU list, but it failed to remove these objects from the LRU list, causing LRU list corruption. This caused use-after-free when the shrinker (gfs2_qd_shrink_scan) tried to access already-freed objects on the LRU list.
Fix this by removing qd objects from the LRU list before freeing them in qd_put().
Initial fix from Deepanshu Kartikey <[email protected]>.
Weakness: CWE-416
Which versions are affected by CVE-2026-45861?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-45861?
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-2026-45861 being exploited?
There is no known exploitation of CVE-2026-45861 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as AZL-88524, BELL-CVE-2026-45861, DEBIAN-CVE-2026-45861, GHSA-v5c4-8mx9-g6x5, ROOT-OS-UBUNTU-2404-CVE-2026-45861, UBUNTU-CVE-2026-45861.