Medium 5.5Published Apr 22, 2026

CVE-2026-31457mm/damon/sysfs: check contexts->nr in repeat_call_fn

Updated under an hour ago (Oct 27, 2026, 8:25 PM ET)

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Exploited in the last 30 days

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

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 11, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from d809a7c64ba8229286b333c0cba03b1cdfb50238 before 3527e9fdc38570cea0f6ddb7a2c9303d4044b217; from d809a7c64ba8229286b333c0cba03b1cdfb50238 before 652cd0641a763dd0e846b0d12814977fadb2b7d8; from d809a7c64ba8229286b333c0cba03b1cdfb50238 before 6557004a8b59c7701e695f02be03c7e20ed1cc15	CNA record
linux linux_kernel linux:linux_kernel	from 6.17 before 6.18.21; from 6.19 before 6.19.11; 7.0; 7.0; 7.0; 7.0; 7.0	NVD

References

References

https://git.kernel.org/stable/c/3527e9fdc38570cea0f6ddb7a2c9303d4044b217	patch
https://git.kernel.org/stable/c/652cd0641a763dd0e846b0d12814977fadb2b7d8	patch
https://git.kernel.org/stable/c/6557004a8b59c7701e695f02be03c7e20ed1cc15	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.