CVE-2026-31458 (GCVE-0-2026-31458)
Vulnerability from cvelistv5
Published
2026-04-22 13:53
Modified
2026-04-22 13:53
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
mm/damon/sysfs: check contexts->nr before accessing contexts_arr[0]
Multiple sysfs command paths dereference contexts_arr[0] without first
verifying that kdamond->contexts->nr == 1. A user can set nr_contexts to
0 via sysfs while DAMON is running, causing NULL pointer dereferences.
In more detail, the issue can be triggered by privileged users like
below.
First, start DAMON and make contexts directory empty
(kdamond->contexts->nr == 0).
# damo start
# cd /sys/kernel/mm/damon/admin/kdamonds/0
# echo 0 > contexts/nr_contexts
Then, each of below commands will cause the NULL pointer dereference.
# echo update_schemes_stats > state
# echo update_schemes_tried_regions > state
# echo update_schemes_tried_bytes > state
# echo update_schemes_effective_quotas > state
# echo update_tuned_intervals > state
Guard all commands (except OFF) at the entry point of
damon_sysfs_handle_cmd().
References
Impacted products
{
"containers": {
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"programFiles": [
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"programFiles": [
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"versions": [
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{
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"version": "6.12.80",
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{
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"version": "6.18.21",
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{
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"status": "unaffected",
"version": "6.19.11",
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{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix"
}
]
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],
"cpeApplicability": [
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"nodes": [
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"cpeMatch": [
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"versionStartIncluding": "5.18",
"vulnerable": true
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"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmm/damon/sysfs: check contexts-\u003enr before accessing contexts_arr[0]\n\nMultiple sysfs command paths dereference contexts_arr[0] without first\nverifying that kdamond-\u003econtexts-\u003enr == 1. A user can set nr_contexts to\n0 via sysfs while DAMON is running, causing NULL pointer dereferences.\n\nIn more detail, the issue can be triggered by privileged users like\nbelow.\n\nFirst, start DAMON and make contexts directory empty\n(kdamond-\u003econtexts-\u003enr == 0).\n\n # damo start\n # cd /sys/kernel/mm/damon/admin/kdamonds/0\n # echo 0 \u003e contexts/nr_contexts\n\nThen, each of below commands will cause the NULL pointer dereference.\n\n # echo update_schemes_stats \u003e state\n # echo update_schemes_tried_regions \u003e state\n # echo update_schemes_tried_bytes \u003e state\n # echo update_schemes_effective_quotas \u003e state\n # echo update_tuned_intervals \u003e state\n\nGuard all commands (except OFF) at the entry point of\ndamon_sysfs_handle_cmd()."
}
],
"providerMetadata": {
"dateUpdated": "2026-04-22T13:53:50.883Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/aba546061341b56e9ffb37e1eb661a3628b6ec12"
},
{
"url": "https://git.kernel.org/stable/c/1e8da792672481d603fa7cd0d815577220a3ee27"
},
{
"url": "https://git.kernel.org/stable/c/708033c231bd782858f4ddbb46ee874a5a5fbdab"
},
{
"url": "https://git.kernel.org/stable/c/bbe03ad3fb9e714191757ca7b41582f930be7be2"
},
{
"url": "https://git.kernel.org/stable/c/1bfe9fb5ed2667fb075682408b776b5273162615"
}
],
"title": "mm/damon/sysfs: check contexts-\u003enr before accessing contexts_arr[0]",
"x_generator": {
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"cveMetadata": {
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"assignerShortName": "Linux",
"cveId": "CVE-2026-31458",
"datePublished": "2026-04-22T13:53:50.883Z",
"dateReserved": "2026-03-09T15:48:24.092Z",
"dateUpdated": "2026-04-22T13:53:50.883Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2"
}
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Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
- Confirmed: The vulnerability is confirmed from an analyst perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
- Patched: This vulnerability was successfully patched by the user reporting the sighting.
- Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
- Not confirmed: The user expresses doubt about the veracity of the vulnerability.
- Not patched: This vulnerability was not successfully patched by the user reporting the sighting.
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