SB2026032549 - Double Free in Linux kernel unix

Description

This security bulletin contains information about 1 vulnerability.

1) Double Free (CVE-ID: CVE-2026-23394)

CWE-ID: CWE-415 - Double Free

CVSSv4: 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/E:U/U:Clear

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to a race condition in the af_unix garbage collection mechanism when handling MSG_PEEK system calls. A local user can send a specially crafted sequence of system calls involving MSG_PEEK and socket closure to trigger incorrect garbage collection of active Unix domain sockets, leading to a denial of service.

The issue arises when MSG_PEEK increases a file reference count without synchronizing with garbage collection, causing the collector to incorrectly identify live sockets as dead and purge their receive queues.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/37dd7ab332396eb8dd80b2dc7ea4b61abf767436
• https://git.kernel.org/stable/c/e5b31d988a41549037b8d8721a3c3cae893d8670