tipc: serialize udp bearer replicast list updates
In the Linux kernel, the following vulnerability has been resolved: tipc: serialize udp bearer replicast list updates tipc_udp_rcast_add() and cleanup_bearer() both update ub->rcast.list with list_add_rcu() / list_del_rcu(), but nothing serializes them. The add runs from the encap receive softirq (via tipc_udp_rcast_disc()) without rtnl_lock(), so it can race the cleanup delete and corrupt the list: list_del corruption. prev->next should be ffff8880298d7ab8, but was ffff88802449ad38. (prev=ffff888027e3ec98) kernel BUG at lib/list_debug.c:62! RIP: __list_del_entry_valid_or_report+0x17a/0x200 Workqueue: events cleanup_bearer Call Trace: cleanup_bearer (net/tipc/udp_media.c:811) process_one_work (kernel/workqueue.c:3302) worker_thread (kernel/workqueue.c:3466) The bearer can be enabled from an unprivileged user namespace, as the TIPCv2 generic-netlink ops carry no GENL_ADMIN_PERM. Add a spinlock to struct udp_bearer and take it around the list_add_rcu() in tipc_udp_rcast_add() and the list_del_rcu() loop in cleanup_bearer() so the two writers can no longer corrupt the list. Reject a duplicate peer under the same lock before allocating, and remove tipc_udp_is_known_peer(). The old lockless pre-check in tipc_udp_rcast_disc() was racy: two softirqs discovering the same peer could both find it absent and add it twice. cleanup_bearer() runs from a workqueue after tipc_udp_disable() clears the bearer's up bit, so an encap softirq can still reach tipc_udp_rcast_add() and add a peer aft
CVE-2026-68323
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-2026-68323
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": "ef20cd4dd1633987bcf46ac34ace2c8af212361f",
"lessThan": "3ff6b534d20824cddab99c81ea3bd1144e635626",
"versionType": "git"
},
{
"status": "affected",
"version": "ef20cd4dd1633987bcf46ac34ace2c8af212361f",
"lessThan": "3ff143a884a19bfcf3aebd999b02274fe44f46f3",
"versionType": "git"
},
{
"status": "affected",
"version": "ef20cd4dd1633987bcf46ac34ace2c8af212361f",
"lessThan": "5d3cea7d41dc72073fea6f879815c9b57c3b330d",
"versionType": "git"
},
{
"status": "affected",
"version": "ef20cd4dd1633987bcf46ac34ace2c8af212361f",
"lessThan": "d70c81001df9320d3445e664428a1d408b5ba896",
"versionType": "git"
},
{
"status": "affected",
"version": "ef20cd4dd1633987bcf46ac34ace2c8af212361f",
"lessThan": "350e592ff4e30e48ffb55e142d11a73e63f4869c",
"versionType": "git"
}
],
"programFiles": [
"net/tipc/udp_media.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.9"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.9",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "6.6.160",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.114",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.57",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.6",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/tipc/udp_media.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-68323
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #46464 · Revision 1
- Added to Heist Feed
- Publisher date