clsact: Fix use-after-free in init/destroy rollback asymmetry
In the Linux kernel, the following vulnerability has been resolved: clsact: Fix use-after-free in init/destroy rollback asymmetry Fix a use-after-free in the clsact qdisc upon init/destroy rollback asymmetry. The latter is achieved by first fully initializing a clsact instance, and then in a second step having a replacement failure for the new clsact qdisc instance. clsact_init() initializes ingress first and then takes care of the egress part. This can fail midway, for example, via tcf_block_get_ext(). Upon failure, the kernel will trigger the clsact_destroy() callback. Commit 1cb6f0bae504 ("bpf: Fix too early release of tcx_entry") details the way how the transition is happening. If tcf_block_get_ext on the q->ingress_block ends up failing, we took the tcx_miniq_inc reference count on the ingress side, but not yet on the egress side. clsact_destroy() tests whether the {ingress,egress}_entry was non-NULL. However, even in midway failure on the replacement, both are in fact non-NULL with a valid egress_entry from the previous clsact instance. What we really need to test for is whether the qdisc instance-specific ingress or egress side previously got initialized. This adds a small helper for checking the miniq initialization called mini_qdisc_pair_inited, and utilizes that upon clsact_destroy() in order to fix the use-after-free scenario. Convert the ingress_destroy() side as well so both are consistent to each other.
CVE-2026-23413
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-2026-23413
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": "230bb13650b0f186f540500fd5f5f7096a822a2a",
"lessThan": "a73d95b57bf9faebdfed591bcb7ed9292062a84c",
"versionType": "git"
},
{
"status": "affected",
"version": "1cb6f0bae50441f4b4b32a28315853b279c7404e",
"lessThan": "37bef86e5428d59f70a4da82b80f9a8f252fecbe",
"versionType": "git"
},
{
"status": "affected",
"version": "1cb6f0bae50441f4b4b32a28315853b279c7404e",
"lessThan": "4c9af67f99aa3e51b522c54968ab3ac8272be41c",
"versionType": "git"
},
{
"status": "affected",
"version": "1cb6f0bae50441f4b4b32a28315853b279c7404e",
"lessThan": "0509b762bc5e8ea7b8391130730c6d8502fc6e69",
"versionType": "git"
},
{
"status": "affected",
"version": "1cb6f0bae50441f4b4b32a28315853b279c7404e",
"lessThan": "a0671125d4f55e1e98d9bde8a0b671941987e208",
"versionType": "git"
},
{
"status": "affected",
"version": "f61ecf1bd5b562ebfd7d430ccb31619857e80857",
"versionType": "git"
},
{
"status": "affected",
"version": "6.6.41",
"lessThan": "6.6.130",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.9.10",
"lessThan": "6.10",
"versionType": "semver"
}
],
"programFiles": [
"include/net/sch_generic.h",
"net/sched/sch_ingress.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.10"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.10",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.130",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.78",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.20",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.10",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/sch_generic.h",
"net/sched/sch_ingress.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-23413
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39845 · Revision 1
- Added to Heist Feed
- Publisher date