SB20260816219 - Use-after-free in Linux kernel smc
Published: August 16, 2026
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 1 vulnerability.
1) Use-after-free (CVE-ID: CVE-2026-74493)
CWE-ID: CWE-416 - Use After Free
CVSSv4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]
The vulnerability allows a local user to cause a denial of service.
The vulnerability exists due to a use-after-free in __smc_lgr_terminate() in the SMC networking subsystem when terminating a link group while a concurrent close unregisters a connection. A local user can trigger overlapping close and link group termination operations to cause a denial of service.
The issue is caused by a race condition involving socket reference handling for a connection stored in lgr->conns_all.
Remediation
Install update from vendor's website.
References
- https://git.kernel.org/stable/c/281c103a8eaed59001ce952f231df1b07674215a
- https://git.kernel.org/stable/c/5a42f162b857019a4c10ff687dc3bcdf51831865
- https://git.kernel.org/stable/c/f0541a775d04c88e90ba448e35ce0d743512822a
- https://git.kernel.org/stable/c/f621d6ebeebb6374342571e4ddf45fdbc420f6cd
- https://git.kernel.org/stable/c/f807a63d0d95680c34f677700da9148a07d7c78f