blk-cgroup: skip dying blkg in blkcg_activate_policy()
In the Linux kernel, the following vulnerability has been resolved: blk-cgroup: skip dying blkg in blkcg_activate_policy() When switching IO schedulers on a block device, blkcg_activate_policy() can race with concurrent blkcg deletion, leading to a use-after-free in rcu_accelerate_cbs. T1: T2: blkg_destroy kill(&blkg->refcnt) // blkg->refcnt=1->0 blkg_release // call_rcu(__blkg_release) ... blkg_free_workfn ->pd_free_fn(pd) elv_iosched_store elevator_switch ... iterate blkg list blkg_get(blkg) // blkg->refcnt=0->1 list_del_init(&blkg->q_node) blkg_put(pinned_blkg) // blkg->refcnt=1->0 blkg_release // call_rcu again rcu_accelerate_cbs // uaf Fix this by checking hlist_unhashed(&blkg->blkcg_node) before getting a reference to the blkg. This is the same check used in blkg_destroy() to detect if a blkg has already been destroyed. If the blkg is already unhashed, skip processing it since it's being destroyed.
CVE-2026-90325
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-90325
Linux
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Linux
Source reference: /containers/cna/affected/1/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "81c1188905f88b77743d1fdeeedfc8cb7b67787d",
"lessThan": "b5dae1cd0d8368b4338430ff93403df67f0b8bcc",
"versionType": "git"
},
{
"status": "affected",
"version": "bfe46d2efe46c5c952f982e2ca94fe2ec5e58e2a",
"lessThan": "083b58373463a6e5ee60ecb135269348f68ad7df",
"versionType": "git"
},
{
"status": "affected",
"version": "f1c006f1c6850c14040f8337753a63119bba39b9",
"lessThan": "1a267295b1ea6a6477963f3fda84adfecd48fcad",
"versionType": "git"
},
{
"status": "affected",
"version": "f1c006f1c6850c14040f8337753a63119bba39b9",
"lessThan": "7337d012ca3fc3a6a2d1c8e2a19c6d97c38b410d",
"versionType": "git"
},
{
"status": "affected",
"version": "f1c006f1c6850c14040f8337753a63119bba39b9",
"lessThan": "3d8c3da95c75a4d312e272fc7b4076dd3ba9115c",
"versionType": "git"
},
{
"status": "affected",
"version": "f1c006f1c6850c14040f8337753a63119bba39b9",
"lessThan": "d8c872901e6459339374e9eea80aa919176c2ccd",
"versionType": "git"
},
{
"status": "affected",
"version": "f1c006f1c6850c14040f8337753a63119bba39b9",
"lessThan": "5e9220389920f33b6a804d50c548cd0cd1b04634",
"versionType": "git"
},
{
"status": "affected",
"version": "6.1.16",
"lessThan": "6.1.17",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.2.3",
"lessThan": "6.2.4",
"versionType": "semver"
}
],
"programFiles": [
"block/blk-cgroup.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.3"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.3",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.1.17",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.2.4",
"versionType": "semver",
"lessThanOrEqual": "6.2.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.52",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.6",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"block/blk-cgroup.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-90325
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #36672 · Revision 1
- Added to Heist Feed
- Publisher date