openvswitch: Fix CT limit teardown use-after-free
In the Linux kernel, the following vulnerability has been resolved: openvswitch: Fix CT limit teardown use-after-free Packet processing uses CT limit state under RCU, while netns teardown frees that state under ovs_mutex. The CT limit pointer was neither removed from readers nor protected by a grace period, allowing packet processing to dereference the freed state. An unprivileged user can trigger this bug from a user and network namespace, causing a slab-use-after-free in ovs_ct_execute() when the netns is torn down. Publish the CT limit pointer through RCU, remove it before teardown, and wait for readers before freeing its contents. Keep ovs_mutex around individual CT limit updates, and use the RCU read-side lock while GET traverses the RCU-protected limit lists. Netns teardown detaches the RCU-protected CT limit state in the pernet .pre_exit callback while holding ovs_mutex. The pernet core guarantees an RCU grace period between the .pre_exit and .exit callbacks, so the .exit callback completes the teardown without adding any extra synchronization. The netlink command handlers do not need NULL checks because the userspace netlink socket holds an active reference to its network namespace while a request is processed. The per-netns exit path therefore cannot run concurrently with SET, DEL, or GET for that socket's namespace.
CVE-2026-89488
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-2026-89488
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": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "239f26589a6926db28c436e14f28517581ef1385",
"versionType": "git"
},
{
"status": "affected",
"version": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "3b9369881b403f4cdbb11fa998554382bdcc3d8c",
"versionType": "git"
},
{
"status": "affected",
"version": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "3b41d907400cc1dd1da9555b81dca422b1f44433",
"versionType": "git"
},
{
"status": "affected",
"version": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "680f20d5937fa4d1367c59fe83091b78041015f5",
"versionType": "git"
},
{
"status": "affected",
"version": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "bf4aaa7ea2579e24ed7de2e20578a875bebca011",
"versionType": "git"
},
{
"status": "affected",
"version": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "e15407c3a8a005324f633cd46cd8fb58042c1157",
"versionType": "git"
},
{
"status": "affected",
"version": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "6a6d36fadb8537d9b79e72c9fa51885ec0c33e10",
"versionType": "git"
},
{
"status": "affected",
"version": "11efd5cb04a184eea4f57b68ea63dddd463158d1",
"lessThan": "403f96c32c9e24600093d7d0c61c17daeedca957",
"versionType": "git"
}
],
"programFiles": [
"net/openvswitch/conntrack.c",
"net/openvswitch/conntrack.h",
"net/openvswitch/datapath.c",
"net/openvswitch/datapath.h"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.18"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.18",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.270",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.221",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.188",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.157",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.110",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.51",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.2.4",
"versionType": "semver",
"lessThanOrEqual": "7.2.*"
},
{
"status": "unaffected",
"version": "7.3",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/openvswitch/conntrack.c",
"net/openvswitch/conntrack.h",
"net/openvswitch/datapath.c",
"net/openvswitch/datapath.h"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-89488
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #35014 · Revision 1
- Added to Heist Feed
- Publisher date