net/sched: act_ct: fix helper UAF due to extensions realloc
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: fix helper UAF due to extensions realloc While calling the helpers, a raw pointer to the extensions area is wired into expectations list: -> nf_ct_helper() -> helper->help() -> nf_ct_expect_related_report() -> nf_ct_expect_insert() -> hlist_add_head_rcu(&exp->lnode, &master_help->expectations) In case the connection is not confirmed yet, more extensions can be added afterwards with *_ext_add() calls reallocating the extension space and leaving the now invalid pointer in the expectations list that is later accessed while removing the expectation. Make sure that helpers are called at the end after all the other extensions are already added. Note that the helper rejection now leaves the mark and labels set, but that's not different from how the NAT was handled before or how the mark and the labels were handled on confirmation failure. And there are no atomicity guarantees provided by the API anyway.
CVE-2026-98442
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-2026-98442
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": "a21b06e7319129994f339ed47f512bbe57b77f5b",
"lessThan": "31f5fe29a572037ee19c233dfe506849940c484b",
"versionType": "git"
},
{
"status": "affected",
"version": "a21b06e7319129994f339ed47f512bbe57b77f5b",
"lessThan": "1679bbf5fbeac52a310b1a58b2b301bbf388bdbf",
"versionType": "git"
},
{
"status": "affected",
"version": "a21b06e7319129994f339ed47f512bbe57b77f5b",
"lessThan": "812c16a255e7773a544e88b39ae6daed25544d30",
"versionType": "git"
},
{
"status": "affected",
"version": "a21b06e7319129994f339ed47f512bbe57b77f5b",
"lessThan": "8988f4d11f3fba0ab38122178836c683ad516a05",
"versionType": "git"
},
{
"status": "affected",
"version": "a21b06e7319129994f339ed47f512bbe57b77f5b",
"lessThan": "dad19b59da050cb60d3f7023dac2a042a84bf0bd",
"versionType": "git"
}
],
"programFiles": [
"net/sched/act_ct.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "6.2"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "6.2",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.112",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.55",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.9",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/act_ct.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-98442
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #55671 · Revision 1
- Added to Heist Feed
- Publisher date