CVE-2026-31457 (GCVE-0-2026-31457)

Vulnerability from cvelistv5 – Published: 2026-04-22 13:53 – Updated: 2026-04-22 13:53
VLAI?
Title
mm/damon/sysfs: check contexts->nr in repeat_call_fn
Summary
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
Severity ?
No CVSS data available.
Assigner
References
Impacted products
Vendor Product Version
Linux Linux Affected: d809a7c64ba8229286b333c0cba03b1cdfb50238 , < 3527e9fdc38570cea0f6ddb7a2c9303d4044b217 (git)
Affected: d809a7c64ba8229286b333c0cba03b1cdfb50238 , < 652cd0641a763dd0e846b0d12814977fadb2b7d8 (git)
Affected: d809a7c64ba8229286b333c0cba03b1cdfb50238 , < 6557004a8b59c7701e695f02be03c7e20ed1cc15 (git)
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    Linux Linux Affected: 6.17
Unaffected: 0 , < 6.17 (semver)
Unaffected: 6.18.21 , ≤ 6.18.* (semver)
Unaffected: 6.19.11 , ≤ 6.19.* (semver)
Unaffected: 7.0 , ≤ * (original_commit_for_fix)
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          "programFiles": [
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          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/sysfs: check contexts-\u003enr in repeat_call_fn\n\ndamon_sysfs_repeat_call_fn() calls damon_sysfs_upd_tuned_intervals(),\ndamon_sysfs_upd_schemes_stats(), and\ndamon_sysfs_upd_schemes_effective_quotas() without checking contexts-\u003enr. \nIf nr_contexts is set to 0 via sysfs while DAMON is running, these\nfunctions dereference contexts_arr[0] and cause a NULL pointer\ndereference.  Add the missing check.\n\nFor example, the issue can be reproduced using DAMON sysfs interface and\nDAMON user-space tool (damo) [1] like below.\n\n    $ sudo damo start --refresh_interval 1s\n    $ echo 0 | sudo tee \\\n            /sys/kernel/mm/damon/admin/kdamonds/0/contexts/nr_contexts"
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        "dateUpdated": "2026-04-22T13:53:50.220Z",
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        "shortName": "Linux"
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          "url": "https://git.kernel.org/stable/c/6557004a8b59c7701e695f02be03c7e20ed1cc15"
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    "cveId": "CVE-2026-31457",
    "datePublished": "2026-04-22T13:53:50.220Z",
    "dateReserved": "2026-03-09T15:48:24.092Z",
    "dateUpdated": "2026-04-22T13:53:50.220Z",
    "state": "PUBLISHED"
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}


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  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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