CVE-2026-46183 mm/damon/sysfs-schemes: protect path kfree() with damon_sysfs_lock
A race condition in the Linux kernel DAMON sysfs interface allows a local attacker to trigger a use-after-free, potentially leading to privilege escalation or code execution.
- 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-2026-46183?
CVE-2026-46183 is a high-severity use after free vulnerability in Linux kernel, published on 28 May 2026. 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:
mm/damon/sysfs-schemes: protect path kfree() with damon_sysfs_lock
damon_sysfs_quot_goal->path can be read and written by users, via DAMON sysfs 'path' file. It can also be indirectly read, for the parameters {on,off}line committing to DAMON. The reads for parameters committing are protected by damon_sysfs_lock to avoid the sysfs files being destroyed while any of the parameters are being read. But the user-driven direct reads and writes are not protected by any lock, while the write is deallocating the path-pointing buffer. As a result, the readers could read the already freed buffer (user-after-free). Note that the user-reads don't race when the same open file is used by the writer, due to kernfs's open file locking. Nonetheless, doing the reads and writes with separate open files would be common. Fix it by protecting both the user-direct reads and writes with damon_sysfs_lock.
Weakness: CWE-415
Which versions are affected by CVE-2026-46183?
It affects 1 product.
Products include Linux kernel.
How do I fix CVE-2026-46183?
Apply the vendor's patch.
Upgrade to the fixed version. These bugs are found with fuzzing and sanitisers and avoided by memory-safe languages. More about Use after free.
Is CVE-2026-46183 being exploited?
There is no known exploitation of CVE-2026-46183 in the wild and no public exploit code.
Other vulnerabilities in Linux kernel
Sources
Also known as DEBIAN-CVE-2026-46183, GHSA-82v4-79hw-3g4g, UBUNTU-CVE-2026-46183.