net/smc: fix socket use-after-free during link group termination
In the Linux kernel, the following vulnerability has been resolved: net/smc: fix socket use-after-free during link group termination __smc_lgr_terminate() drops conns_lock after finding a connection in lgr->conns_all, but before taking a reference on its socket. The connection is embedded in the socket, and its registration reference protects it only while the connection remains in the tree. A concurrent close can unregister the connection and drop that reference, freeing the socket before the termination worker reaches sock_hold(). The race is reachable when close overlaps link group termination. Local stress testing reproduced the use-after-free and KASAN reported: BUG: KASAN: slab-use-after-free in __smc_lgr_terminate.part.0 [smc] Write of size 4 by task kworker/3:3 Workqueue: events smc_lgr_terminate_work [smc] __smc_lgr_terminate.part.0 [smc] The socket was allocated by smc_create(), freed through slab_free_after_rcu_debug(), and was followed by: refcount_t: addition on 0; use-after-free. __smc_lgr_terminate.part.0 [smc] Take the socket reference while conns_lock still protects the tree entry. The unregister path then cannot drop the last reference until termination has finished using the socket.
CVE-2026-74493
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-2026-74493
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": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "ff44f2df57fb5560bdc75eb977867643e764a262",
"versionType": "git"
},
{
"status": "affected",
"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "9fb17c95b8f0683570fca1fb2792264147af937a",
"versionType": "git"
},
{
"status": "affected",
"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "bea8dc14de2d56aca749d368563e6888217710a5",
"versionType": "git"
},
{
"status": "affected",
"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "5a42f162b857019a4c10ff687dc3bcdf51831865",
"versionType": "git"
},
{
"status": "affected",
"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "281c103a8eaed59001ce952f231df1b07674215a",
"versionType": "git"
},
{
"status": "affected",
"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "f807a63d0d95680c34f677700da9148a07d7c78f",
"versionType": "git"
},
{
"status": "affected",
"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "f0541a775d04c88e90ba448e35ce0d743512822a",
"versionType": "git"
},
{
"status": "affected",
"version": "69318b5215f2dc32c345a3d65b98b4b1bf29c007",
"lessThan": "f621d6ebeebb6374342571e4ddf45fdbc420f6cd",
"versionType": "git"
}
],
"programFiles": [
"net/smc/smc_core.c"
],
"defaultStatus": "unaffected"
},
{
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"product": "Linux",
"versions": [
{
"status": "affected",
"version": "5.5"
},
{
"status": "unaffected",
"version": "0",
"lessThan": "5.5",
"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": "6.6.151",
"versionType": "semver",
"lessThanOrEqual": "6.6.*"
},
{
"status": "unaffected",
"version": "6.12.103",
"versionType": "semver",
"lessThanOrEqual": "6.12.*"
},
{
"status": "unaffected",
"version": "6.18.44",
"versionType": "semver",
"lessThanOrEqual": "6.18.*"
},
{
"status": "unaffected",
"version": "7.1.8",
"versionType": "semver",
"lessThanOrEqual": "7.1.*"
},
{
"status": "unaffected",
"version": "7.2",
"versionType": "original_commit_for_fix",
"lessThanOrEqual": "*"
}
],
"programFiles": [
"net/smc/smc_core.c"
],
"defaultStatus": "affected"
}
]- Related CVEs
- CVE-2026-74493
Source reference:
/cveMetadata/cveId
Publisher severity
critical
Source reference: /containers/cna/metrics
- Event
- #33178 · Revision 1
- Added to Heist Feed
- Publisher date