tipc: read le->link under the node lock in tipc_node_link_down()
In the Linux kernel, the following vulnerability has been resolved: tipc: read le->link under the node lock in tipc_node_link_down() tipc_node_link_down() caches the link pointer before taking n->lock: struct tipc_link *l = le->link; /* unlocked */ if (!l) return; tipc_node_write_lock(n); if (!tipc_link_is_establishing(l)) { /* deref l */ ... tipc_link_reset(l); /* write into l */ if (delete) { kfree(l); le->link = NULL; The delete=true caller frees that very object under n->lock, so the lock does not protect the cached pointer against it: - CPU A, delete=false: tipc_rcv() on TIPC_LINK_DOWN_EVT, or the link supervision timer via tipc_node_timeout(), reads l unlocked and then dereferences it under n->lock; - CPU B, delete=true: netlink TIPC_NL_BEARER_DISABLE -> bearer_disable() -> tipc_node_delete_links() -> tipc_node_link_down(n, bearer_id, true) -> kfree(l). The link is freed with plain kfree(), not kfree_rcu(), and for UDP bearers disable_media() only schedules the asynchronous cleanup_bearer() work, so its synchronize_net() runs after the links are already gone. An in-flight CPU A that has read l therefore dereferences freed memory once B frees it: a use-after-free read in tipc_link_is_establishing(), and a use-after-free write via tipc_link_reset() on the establishing branch. The following trace was captured on 7.2.0-rc5-00284-gaf39eb111ce6: BUG: KASAN: slab-use-after-free in tipc_link_is_establishing (net/tipc/link.c:285) Read of size 4 at addr ffff88802e2aa068 by task s
CVE-2026-74609
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-2026-74609
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": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "2be741ad565c610871a6a95062c12c39da7168fd",
"versionType": "git"
},
{
"status": "affected",
"version": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "69d209461c110388710e483a130caf051e4fd09a",
"versionType": "git"
},
{
"status": "affected",
"version": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "de017c22135f545ca4e65d1eada22887b64958eb",
"versionType": "git"
},
{
"status": "affected",
"version": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "47ba70891b10b2feb52462086b7fcd2ad75d3ce3",
"versionType": "git"
},
{
"status": "affected",
"version": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "a714d62513befef37f71f4ae89bb1fe173b65f2e",
"versionType": "git"
},
{
"status": "affected",
"version": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "c3f2347a47754eac690967cfd82cb6d559817b07",
"versionType": "git"
},
{
"status": "affected",
"version": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "5558a8312452ddb21eff22b1cbd84302ad951944",
"versionType": "git"
},
{
"status": "affected",
"version": "73f646cec35477b5099d7e952297cb9e1855be45",
"lessThan": "cba9ccb47e9fa4cc77692fb896cc5ab57a667882",
"versionType": "git"
}
],
"programFiles": [
"net/tipc/node.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "4.4"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "4.4",
"versionType": "semver"
},
{
"status": "unaffected",
"version": "5.10.265",
"versionType": "semver",
"lessThanOrEqual": "5.10.*"
},
{
"status": "unaffected",
"version": "5.15.216",
"versionType": "semver",
"lessThanOrEqual": "5.15.*"
},
{
"status": "unaffected",
"version": "6.1.183",
"versionType": "semver",
"lessThanOrEqual": "6.1.*"
},
{
"status": "unaffected",
"version": "6.6.152",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.104",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.45",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.9",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/tipc/node.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74609
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #33235 · Revision 1
- Added to Heist Feed
- Publisher date