CVE-2026-74261

A low impact race condition flaw was found in the ALSA sequencer FIFO resize path of the Linux kernel used in Red Hat Enterprise Linux. During a client pool resize, snd_seq_fifo_resize() swaps the FIFO to a new cell pool and detaches the old cell list, but a concurrent snd_seq_fifo_event_in() can duplicate an event from the old pool, and snd_seq_read() can put back a previously dequeued cell after the swap. Relinking such a stale cell keeps the retired pool's cell counter elevated, so snd_seq_pool_delete() can wait indefinitely for the old pool to drain and the resize ioctl blocks. A local attacker with access to the ALSA sequencer could exploit this race to cause a denial of service limited to the resize path; confidentiality and integrity are not affected. Because this is a timing-dependent local denial of service with low security impact, the fix is deferred for the affected Red Hat Enterprise Linux kernel and kernel-rt streams and will be addressed in a future update; the residual risk is that a local user can block sequencer pool resize operations. Red Hat In-Vehicle OS is not affected because the vulnerable code is not present, and Red Hat Enterprise Linux 6 Extended Lifecycle Support is out of support scope. Red Hat assesses the severity of this flaw as low because exploitation requires local access and a narrow race window, and it results only in a blocked resize operation.