CVE-2025-37839 jbd2: remove wrong sb->s_sequence check
A logic error in the Linux kernel's jbd2 journaling code can trigger spurious warnings, 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-2025-37839?
CVE-2025-37839 is a high-severity denial of service vulnerability in Debian Debian Linux, published on 9 May 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:
jbd2: remove wrong sb->s_sequence check
Journal emptiness is not determined by sb->s_sequence == 0 but rather by sb->s_start == 0 (which is set a few lines above). Furthermore 0 is a valid transaction ID so the check can spuriously trigger. Remove the invalid WARN_ON.
Which versions are affected by CVE-2025-37839?
It affects 2 products.
Products include Debian Debian Linux, Linux kernel.
How do I fix CVE-2025-37839?
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-2025-37839 being exploited?
There is no known exploitation of CVE-2025-37839 in the wild and no public exploit code.
Other vulnerabilities in Debian Debian Linux
Sources
Also known as BELL-CVE-2025-37839, DEBIAN-CVE-2025-37839, GHSA-8rhx-6jcw-6ghv, ROOT-OS-DEBIAN-12-CVE-2025-37839, ROOT-OS-UBUNTU-2204-CVE-2025-37839, ROOT-OS-UBUNTU-2404-CVE-2025-37839 and 1 more.