Linux AF_UNIX Socket Race Enables Local Denial of Service

CVE-2024-26923 is a race condition in the Linux kernel's AF_UNIX socket garbage collector that occurs when garbage collection runs concurrently with connect() on a partially initialized socket carrying SCM_RIGHTS file descriptors. The race can incorrectly increase an in-flight reference count, leave a dangling pointer in gc_inflight_list, and cause inaccurate active-socket accounting, allowing local resource exhaustion and denial of service. The affected code is net/unix/garbage.c, and the issue has existed since Linux kernel 2.6.23.

Exploitation requires local low-privileged access and difficult-to-reproduce timing conditions, but Red Hat assigns a Moderate severity rating with CVSS 7.0. Fixed upstream kernels include 5.15.156, 6.1.87, 6.6.28, 6.8.7, and 6.9-rc4; Red Hat has issued corrected kernel packages for multiple RHEL 8 and RHEL 9 streams. Organizations should deploy current vendor kernel updates rather than cherry-picking patches; no separate mitigation is known.