CVE-2025-68350 exfat: fix divide-by-zero in exfat_allocate_bitmap
A divide-by-zero error in the Linux kernel exfat filesystem allows local attackers to crash the system by mounting a crafted filesystem.
- 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-2025-68350?
CVE-2025-68350 is a denial of service vulnerability in Linux, published on 24 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:
exfat: fix divide-by-zero in exfat_allocate_bitmap
The variable max_ra_count can be 0 in exfat_allocate_bitmap(), which causes a divide-by-zero error in the subsequent modulo operation (i % max_ra_count), leading to a system crash. When max_ra_count is 0, it means that readahead is not used. This patch load the bitmap without readahead.
Which versions are affected by CVE-2025-68350?
How do I fix CVE-2025-68350?
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-2025-68350 being exploited?
There is no known exploitation of CVE-2025-68350 in the wild and no public exploit code.
Sources
Also known as BELL-CVE-2025-68350, GHSA-3m3f-rvf7-9vp6, UBUNTU-CVE-2025-68350.