net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks
In the Linux kernel, the following vulnerability has been resolved: net/sched: Only allow act_ct to bind to clsact/ingress qdiscs and shared blocks As Paolo said earlier [1]: "Since the blamed commit below, classify can return TC_ACT_CONSUMED while the current skb being held by the defragmentation engine. As reported by GangMin Kim, if such packet is that may cause a UaF when the defrag engine later on tries to tuch again such packet." act_ct was never meant to be used in the egress path, however some users are attaching it to egress today [2]. Attempting to reach a middle ground, we noticed that, while most qdiscs are not handling TC_ACT_CONSUMED, clsact/ingress qdiscs are. With that in mind, we address the issue by only allowing act_ct to bind to clsact/ingress qdiscs and shared blocks. That way it's still possible to attach act_ct to egress (albeit only with clsact). [1] https://lore.kernel.org/netdev/674b8cbfc385c6f37fb29a1de08d8fe5c2b0fbee.1771321118.git.pabeni@redhat.com/ [2] https://lore.kernel.org/netdev/cc6bfb4a-4a2b-42d8-b9ce-7ef6644fb22b@ovn.org/
CVE-2026-23270
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-2026-23270
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": "172ba7d46c202e679f3ccb10264c67416aaeb1c4",
"lessThan": "bc4e5bb529823a09f02dbe96169de679a9db26e0",
"versionType": "git"
},
{
"status": "affected",
"version": "0b5b831122fc3789fff75be433ba3e4dd7b779d4",
"lessThan": "fb3c380a54e33d1fd272cc342faa906d787d7ef1",
"versionType": "git"
},
{
"status": "affected",
"version": "73f7da5fd124f2cda9161e2e46114915e6e82e97",
"lessThan": "5a110ddcc99bda77a28598b3555fe009eaab3828",
"versionType": "git"
},
{
"status": "affected",
"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
"lessThan": "524ce8b4ea8f64900b6c52b6a28df74f6bc0801e",
"versionType": "git"
},
{
"status": "affected",
"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
"lessThan": "380ad8b7c65ea7aa10ef2258297079ed5ac1f5b6",
"versionType": "git"
},
{
"status": "affected",
"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
"lessThan": "9deda0fcda5c1f388c5e279541850b71a2ccfcf4",
"versionType": "git"
},
{
"status": "affected",
"version": "3f14b377d01d8357eba032b4cabc8c1149b458b6",
"lessThan": "11cb63b0d1a0685e0831ae3c77223e002ef18189",
"versionType": "git"
},
{
"status": "affected",
"version": "f5346df0591d10bc948761ca854b1fae6d2ef441",
"versionType": "git"
},
{
"status": "affected",
"version": "5.15.148",
"lessThan": "5.15.203",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.1.75",
"lessThan": "6.1.167",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.6.14",
"lessThan": "6.6.130",
"versionType": "semver"
},
{
"status": "affected",
"version": "6.7.2",
"lessThan": "6.8",
"versionType": "semver"
}
],
"programFiles": [
"include/net/act_api.h",
"net/sched/act_ct.c",
"net/sched/cls_api.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.8"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.8",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.15.203",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.167",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.130",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.77",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.18",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "6.19.8",
"versionType": "semver",
"lessThanOrEqual": "6.19.*"
},
{
"status": "unaffected",
"version": "7.0",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"include/net/act_api.h",
"net/sched/act_ct.c",
"net/sched/cls_api.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-23270
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #39830 · Revision 1
- Added to Heist Feed
- Publisher date