CVE-2025-40333 f2fs: fix infinite loop in __insert_extent_tree()
A local attacker can cause a kernel infinite loop in the f2fs filesystem by providing corrupted extent data, leading to a denial of service.
- 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-2025-40333?
CVE-2025-40333 is a denial of service vulnerability in Linux, published on 9 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:
f2fs: fix infinite loop in __insert_extent_tree()
When we get wrong extent info data, and look up extent_node in rb tree, it will cause infinite loop (CONFIG_F2FS_CHECK_FS=n). Avoiding this by return NULL and print some kernel messages in that case.
Which versions are affected by CVE-2025-40333?
How do I fix CVE-2025-40333?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-40333 being exploited?
There is no known exploitation of CVE-2025-40333 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-40333, DEBIAN-CVE-2025-40333, GHSA-77hp-5cm4-fcqg, ROOT-OS-DEBIAN-11-CVE-2025-40333, ROOT-OS-DEBIAN-12-CVE-2025-40333, ROOT-OS-DEBIAN-13-CVE-2025-40333 and 3 more.