Riskcovery

CVE-2026-31457

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

State
Published
Severity
Not scored
Published
Apr 22, 2026
Updated
May 11, 2026
Reserved
Mar 9, 2026

Read the record on cve.org

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

Scores

The record has no CVSS score.

Weaknesses

The record names no weakness.

Affected Products

ProductVersions
LinuxLinux
  • d809a7c64ba8229286b333c0cba03b1cdfb50238 to before 3527e9fdc38570cea0f6ddb7a2c9303d4044b217Affected
  • d809a7c64ba8229286b333c0cba03b1cdfb50238 to before 652cd0641a763dd0e846b0d12814977fadb2b7d8Affected
  • d809a7c64ba8229286b333c0cba03b1cdfb50238 to before 6557004a8b59c7701e695f02be03c7e20ed1cc15Affected
LinuxLinux
  • 6.17Affected
  • before 6.17Not affected
  • 6.18.21 through 6.18.*Not affected
  • 6.19.11 through 6.19.*Not affected
  • 7.0 and laterNot affected

References

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