cgroup/rstat: validate cpu before css_rstat_cpu() access
In the Linux kernel, the following vulnerability has been resolved: cgroup/rstat: validate cpu before css_rstat_cpu() access css_rstat_updated() is exposed as a BPF kfunc and accepts a caller-provided cpu argument. The function uses cpu for per-cpu rstat lookups without checking whether it refers to a valid possible CPU. A BPF iter/cgroup program with CAP_BPF and CAP_PERFMON can pass an invalid cpu value. On an unfixed UBSCAN_BOUNDS test kernel, cpu == 0x7fffffff triggers: UBSAN: array-index-out-of-bounds in kernel/cgroup/rstat.c:31:9 index 2147483647 is out of range for type 'long unsigned int [64]' Call Trace: css_rstat_updated bpf_iter_run_prog cgroup_iter_seq_show bpf_seq_read Add cpu validation to the BPF-facing css_rstat_updated() kfunc and move the common implementation to __css_rstat_updated() for in-kernel callers.
CVE-2026-64036
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-2026-64036
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": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "b28b862b07257219755d0b0a7fbe5d23b7c9ea91",
"versionType": "git"
},
{
"status": "affected",
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "3d595affbe00a2e8bf43b9f2947a8efcdc1c059e",
"versionType": "git"
},
{
"status": "affected",
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "6a01413a4e8fcb0263d7bef5075c5f8f4eb3a8b6",
"versionType": "git"
},
{
"status": "affected",
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "fd2bd9fa7700ddf28296486b2598cff2f80cc819",
"versionType": "git"
},
{
"status": "affected",
"version": "a319185be9f5ad13c2a296d448ac52ffe45d194c",
"lessThan": "8817005efbdfdf5d4e4814cb5dc52b53d12917d7",
"versionType": "git"
}
],
"programFiles": [
"block/blk-cgroup.c",
"include/linux/cgroup.h",
"kernel/cgroup/rstat.c",
"mm/memcontrol.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.1"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.1",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.34",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.11",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"block/blk-cgroup.c",
"include/linux/cgroup.h",
"kernel/cgroup/rstat.c",
"mm/memcontrol.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-64036
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #46416 · Revision 1
- Added to Heist Feed
- Publisher date