net/sched: act_ct: Only release RCU read lock after ct_ft
In the Linux kernel, the following vulnerability has been resolved: net/sched: act_ct: Only release RCU read lock after ct_ft When looking up a flow table in act_ct in tcf_ct_flow_table_get(), rhashtable_lookup_fast() internally opens and closes an RCU read critical section before returning ct_ft. The tcf_ct_flow_table_cleanup_work() can complete before refcount_inc_not_zero() is invoked on the returned ct_ft resulting in a UAF on the already freed ct_ft object. This vulnerability can lead to privilege escalation. Analysis from zdi-disclosures@trendmicro.com: When initializing act_ct, tcf_ct_init() is called, which internally triggers tcf_ct_flow_table_get(). static int tcf_ct_flow_table_get(struct net *net, struct tcf_ct_params *params) { struct zones_ht_key key = { .net = net, .zone = params->zone }; struct tcf_ct_flow_table *ct_ft; int err = -ENOMEM; mutex_lock(&zones_mutex); ct_ft = rhashtable_lookup_fast(&zones_ht, &key, zones_params); // [1] if (ct_ft && refcount_inc_not_zero(&ct_ft->ref)) // [2] goto out_unlock; ... } static __always_inline void *rhashtable_lookup_fast( struct rhashtable *ht, const void *key, const struct rhashtable_params params) { void *obj; rcu_read_lock(); obj = rhashtable_lookup(ht, key, params); rcu_read_unlock(); return obj; } At [1], rhashtable_lookup_fast() looks up and returns the corresponding ct_ft from zones_ht . The lookup is performed within an RCU read critical section through rcu_read_lock() / rcu_read_unlock(), which prevents the obje
CVE-2026-46319
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-2026-46319
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": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "ece578ca61e572df96cfc80456357ebfae0b4b9e",
"versionType": "git"
},
{
"status": "affected",
"version": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "a2e0c045c87aa252eb61412e67dd91f2c2b19f81",
"versionType": "git"
},
{
"status": "affected",
"version": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "67c9ecc9f2575273ed1323e312881fc98ac83d6d",
"versionType": "git"
},
{
"status": "affected",
"version": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "f23424a0ddadb494d4bd57056a7ca703312d3a7b",
"versionType": "git"
},
{
"status": "affected",
"version": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "17dfb67cb399b660105d9a8c6100851c0d0cdc70",
"versionType": "git"
},
{
"status": "affected",
"version": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "4c727c6967a41b37efe0f26332ca9ec5b74785a3",
"versionType": "git"
},
{
"status": "affected",
"version": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "3e20e1b3058e0b94638e7b931c138e840e266724",
"versionType": "git"
},
{
"status": "affected",
"version": "138470a9b2cc2e26e6018300394afc3858a54e6a",
"lessThan": "f462dca0c8415bf0058d0ffa476354c4476d0f09",
"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": "5.7"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.7",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.258",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.209",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.175",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.141",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.91",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.33",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.0.10",
"versionType": "semver",
"lessThanOrEqual": "7.0.*"
},
{
"status": "unaffected",
"version": "7.1",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/sched/act_ct.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-46319
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #40679 · Revision 1
- Added to Heist Feed
- Publisher date