CVE-2026-74261

A flaw was found in the ALSA (Advanced Linux Sound Architecture) sequencer component of the Linux kernel. A local attacker could exploit a race condition during the FIFO (First-In, First-Out) resize operation. This vulnerability allows stale data cells to persist, preventing the proper deallocation of memory resources. The consequence is a denial of service, where the system's resize operations become indefinitely blocked.

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.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.