CVE-2024-26601 ext4: regenerate buddy after block freeing failed if under fc replay
A flaw in the Linux kernel ext4 filesystem can cause buddy bitmap corruption during fast commit replay, leading to system instability or 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-2024-26601?
CVE-2024-26601 is a high-severity denial of service vulnerability in Linux kernel, published on 24 Feb 2024. 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:
ext4: regenerate buddy after block freeing failed if under fc replay
This mostly reverts commit 6bd97bf273bd ("ext4: remove redundant mb_regenerate_buddy()") and reintroduces mb_regenerate_buddy(). Based on code in mb_free_blocks(), fast commit replay can end up marking as free blocks that are already marked as such. This causes corruption of the buddy bitmap so we need to regenerate it in that case.
Which versions are affected by CVE-2024-26601?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2024-26601?
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-2024-26601 being exploited?
There is no known exploitation of CVE-2024-26601 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as BELL-CVE-2024-26601, DEBIAN-CVE-2024-26601, GHSA-38g6-vx2q-23wm, UBUNTU-CVE-2024-26601.