CVE-2026-46121: Linux kernel · mm/damon/sysfs-schemes: protect memcg_path kfree() with damon_sysfs_lock
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in eafd6f5372d29b0dd213799b92c2c9c7ad31d7da : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:34 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in eafd6f5372d29b0dd213799b92c2c9c7ad31d7da, c88802d0e8edd14b6cd2daf3000f99adbc4c85c5, baecc45ad60e621ef14d6c1e7f41ef36bbfdf910 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 28 May 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
|
| LinuxLinux | Affected
| Fixed in– |
Description
In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs-schemes: protect memcg_path kfree() with damon_sysfs_lock Patch series "mm/damon/sysfs-schemes: fix use-after-free for [memcg_]path". Reads of 'memcg_path' and 'path' files in DAMON sysfs interface could race with their writes, results in use-after-free. Fix those. This patch (of 2): damon_sysfs_scheme_filter->mmecg_path can be read and written by users, via DAMON sysfs memcg_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 memcg_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.
References
- git.kernel.org/stable/c/b1e9f2d5870776347edef927f9bb3ea19b8e3abb (opens in a new tab)
- git.kernel.org/stable/c/c88802d0e8edd14b6cd2daf3000f99adbc4c85c5 (opens in a new tab)
- git.kernel.org/stable/c/eafd6f5372d29b0dd213799b92c2c9c7ad31d7da (opens in a new tab)
- git.kernel.org/stable/c/baecc45ad60e621ef14d6c1e7f41ef36bbfdf910 (opens in a new tab)
- git.kernel.org/stable/c/1e68eb96e8beb1abefd12dd22c5637795d8a877e (opens in a new tab)