CVE-2026-74593 (GCVE-0-2026-74593)
Vulnerability from cvelistv5
Published
2026-08-22 15:31
Modified
2026-08-23 12:47
Severity ?
VLAI Severity ?
EPSS score ?
Summary
In the Linux kernel, the following vulnerability has been resolved:
sched_ext: Take cgroup_lock() first in scx_cgroup_lock()
scx_cgroup_lock() write-locks scx_cgroup_ops_rwsem and then takes
cgroup_lock(), which can deadlock through kernfs:
scx enable/disable cgroup rmdir cpu.weight write
------------------ ------------ ----------------
cgroup_lock()
percpu_down_write(rwsem)
cgroup_lock()
kernfs_get_active()
percpu_down_read(rwsem)
kernfs_drain()
The enable path waits for the rmdir to release cgroup_mutex. The rmdir,
deactivating the cpu controller's files, waits in kernfs_drain() for the
write's active reference. The write, in scx_group_set_weight(), waits for
the rwsem behind the pending writer.
Take cgroup_lock() first. The set_* paths take no cgroup locks inside the
read side, so a pending write-lock then only waits for read sections that
always run to completion, and no dependency from the rwsem back to
cgroup_mutex remains.
References
Impacted products
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"kernel/sched/ext/ext.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "2ca6b43edf83f8fc368cc3094ee5f3b1e8e0b0f0",
"status": "affected",
"version": "a5bd6ba30b3364354269b81ac55c2edca9a96d6d",
"versionType": "git"
},
{
"lessThan": "a054c9ffa9b7a0dffb763837b91ac9d381ec6d10",
"status": "affected",
"version": "a5bd6ba30b3364354269b81ac55c2edca9a96d6d",
"versionType": "git"
},
{
"lessThan": "5f8b69642d18e1f3e11996707842ac530444e959",
"status": "affected",
"version": "a5bd6ba30b3364354269b81ac55c2edca9a96d6d",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"kernel/sched/ext/ext.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.18"
},
{
"lessThan": "6.18",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.46",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.18.46",
"versionStartIncluding": "6.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.1.9",
"versionStartIncluding": "6.18",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "7.2",
"versionStartIncluding": "6.18",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nsched_ext: Take cgroup_lock() first in scx_cgroup_lock()\n\nscx_cgroup_lock() write-locks scx_cgroup_ops_rwsem and then takes\ncgroup_lock(), which can deadlock through kernfs:\n\n scx enable/disable cgroup rmdir cpu.weight write\n ------------------ ------------ ----------------\n cgroup_lock()\n percpu_down_write(rwsem)\n cgroup_lock()\n kernfs_get_active()\n percpu_down_read(rwsem)\n kernfs_drain()\n\nThe enable path waits for the rmdir to release cgroup_mutex. The rmdir,\ndeactivating the cpu controller\u0027s files, waits in kernfs_drain() for the\nwrite\u0027s active reference. The write, in scx_group_set_weight(), waits for\nthe rwsem behind the pending writer.\n\nTake cgroup_lock() first. The set_* paths take no cgroup locks inside the\nread side, so a pending write-lock then only waits for read sections that\nalways run to completion, and no dependency from the rwsem back to\ncgroup_mutex remains."
}
],
"providerMetadata": {
"dateUpdated": "2026-08-23T12:47:36.437Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/2ca6b43edf83f8fc368cc3094ee5f3b1e8e0b0f0"
},
{
"url": "https://git.kernel.org/stable/c/a054c9ffa9b7a0dffb763837b91ac9d381ec6d10"
},
{
"url": "https://git.kernel.org/stable/c/5f8b69642d18e1f3e11996707842ac530444e959"
}
],
"title": "sched_ext: Take cgroup_lock() first in scx_cgroup_lock()",
"x_generator": {
"engine": "bippy-1.2.0"
}
}
},
"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2026-74593",
"datePublished": "2026-08-22T15:31:44.160Z",
"dateReserved": "2026-08-15T05:44:03.919Z",
"dateUpdated": "2026-08-23T12:47:36.437Z",
"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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