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CVE PROGRAM SOURCE RECORD9.8 Critical

CVE-2026-74493

net/smc: fix socket use-after-free during link group termination

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Status
Published
Published
Updated
Assigning organization
Linux

Description

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.

Affected products

Version statuses are supplied by the assigning organization. Consult the original record for detailed ranges and platform conditions.

Linux Linux

Default version status: unaffected

  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < ff44f2df57fb5560bdc75eb977867643e764a262affected
  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < 9fb17c95b8f0683570fca1fb2792264147af937aaffected
  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < bea8dc14de2d56aca749d368563e6888217710a5affected
  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < 5a42f162b857019a4c10ff687dc3bcdf51831865affected
  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < 281c103a8eaed59001ce952f231df1b07674215aaffected
  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < f807a63d0d95680c34f677700da9148a07d7c78faffected
  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < f0541a775d04c88e90ba448e35ce0d743512822aaffected
  • 69318b5215f2dc32c345a3d65b98b4b1bf29c007 to < f621d6ebeebb6374342571e4ddf45fdbc420f6cdaffected

Linux Linux

Default version status: affected

  • 5.5affected
  • 0 to < 5.5unaffected
  • 5.10.265 to ≤ 5.10.*unaffected
  • 5.15.216 to ≤ 5.15.*unaffected
  • 6.1.183 to ≤ 6.1.*unaffected
  • 6.6.151 to ≤ 6.6.*unaffected
  • 6.12.103 to ≤ 6.12.*unaffected
  • 6.18.44 to ≤ 6.18.*unaffected
  • 7.1.8 to ≤ 7.1.*unaffected
  • 7.2 to ≤ *unaffected

References