CVE-2026-74493net/smc: fix socket use-after-free during link group termination
Updated under an hour ago ()
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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.
- CVSS
- 9.8 CRITICAL (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
- Weakness (CWE)
- Not given
- Known exploited
- Not in CISA's KEV catalog
- EPSS (exploitation in the next 30 days)
- Not loaded for this CVE
- Assigned by
- Linux
- NVD analysis
- Received
- Record last updated
- Oct 16, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
Affected products
Linux Linux linux:linux (from the name) | from 69318b5215f2dc32c345a3d65b98b4b1bf29c007 before ff44f2df57fb5560bdc75eb977867643e764a262; 69318b5215f2dc32c345a3d65b98b4b1bf29c007 builds before 9fb17c95b8f0683570fca1fb2792264147af937a; from 69318b5215f2dc32c345a3d65b98b4b1bf29c007 before bea8dc14de2d56aca749d368563e6888217710a5; 69318b5215f2dc32c345a3d65b98b4b1bf29c007 builds before 5a42f162b857019a4c10ff687dc3bcdf51831865; 69318b5215f2dc32c345a3d65b98b4b1bf29c007 builds before 281c103a8eaed59001ce952f231df1b07674215a; from 69318b5215f2dc32c345a3d65b98b4b1bf29c007 before f807a63d0d95680c34f677700da9148a07d7c78f; from 69318b5215f2dc32c345a3d65b98b4b1bf29c007 before f0541a775d04c88e90ba448e35ce0d743512822a; from 69318b5215f2dc32c345a3d65b98b4b1bf29c007 before f621d6ebeebb6374342571e4ddf45fdbc420f6cd | CNA record |
References
- https://git.kernel.org/stable/c/ff44f2df57fb5560bdc75eb977867643e764a262
- https://git.kernel.org/stable/c/9fb17c95b8f0683570fca1fb2792264147af937a
- https://git.kernel.org/stable/c/bea8dc14de2d56aca749d368563e6888217710a5
- https://git.kernel.org/stable/c/5a42f162b857019a4c10ff687dc3bcdf51831865
- https://git.kernel.org/stable/c/281c103a8eaed59001ce952f231df1b07674215a
- https://git.kernel.org/stable/c/f807a63d0d95680c34f677700da9148a07d7c78f
- https://git.kernel.org/stable/c/f0541a775d04c88e90ba448e35ce0d743512822a
- https://git.kernel.org/stable/c/f621d6ebeebb6374342571e4ddf45fdbc420f6cd
The CVE record on cve.org NVD's entry
The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.