CVE-2026-31457: Linux kernel · mm/damon/sysfs: check contexts->nr in repeat_call_fn
Source GCVE Database
Not known to be exploited · CVSS 5.5 Medium.
Data as of 27 Oct 2026, 00:07 UTC
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 22 Apr 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
Description
In the Linux kernel, the following vulnerability has been resolved: mm/damon/sysfs: check contexts->nr in repeat_call_fn damon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(), damon_sysfs_upd_schemes_stats(), and damon_sysfs_upd_schemes_effective_quotas() without checking contexts->nr. If nr_contexts is set to 0 via sysfs while DAMON is running, these functions dereference contexts_arr[0] and cause a NULL pointer dereference. Add the missing check. For example, the issue can be reproduced using DAMON sysfs interface and DAMON user-space tool (damo) [1] like below. $ sudo damo start --refresh_interval 1s $ echo 0 | sudo tee \ /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts
References
- nvd.nist.gov/vuln/detail/CVE-2026-31457 (opens in a new tab)
- git.kernel.org/stable/c/3527e9fdc38570cea0f6ddb7a2c9303d4044b217 (opens in a new tab)
- git.kernel.org/stable/c/652cd0641a763dd0e846b0d12814977fadb2b7d8 (opens in a new tab)
- git.kernel.org/stable/c/6557004a8b59c7701e695f02be03c7e20ed1cc15 (opens in a new tab)