CVE-2025-39795 block: avoid possible overflow for chunk_sectors check in blk_stack_limits()
An integer overflow in the Linux kernel block layer can cause incorrect chunk size checks, potentially 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-2025-39795?
CVE-2025-39795 is a medium-severity vulnerability in Debian Debian Linux, published on 12 Sep 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:
block: avoid possible overflow for chunk_sectors check in blk_stack_limits()
In blk_stack_limits(), we check that the t->chunk_sectors value is a multiple of the t->physical_block_size value.
However, by finding the chunk_sectors value in bytes, we may overflow the unsigned int which holds chunk_sectors, so change the check to be based on sectors.
Weakness: CWE-674
Which versions are affected by CVE-2025-39795?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-39795?
Apply the vendor's patch.
Is CVE-2025-39795 being exploited?
There is no known exploitation of CVE-2025-39795 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as AZL-67337, AZL-74691, BELL-CVE-2025-39795, DEBIAN-CVE-2025-39795, GHSA-x2v6-jx2x-c364, ROOT-OS-DEBIAN-11-CVE-2025-39795 and 4 more.