CVE-2024-26654: Debian Linux

High severity, CVSS 7.0. EPSS: 0.3% chance of exploitation in the next 30 days.

In the Linux kernel, the following vulnerability has been resolved: ALSA: sh: aica: reorder cleanup operations to avoid UAF bugs The dreamcastcard->timer could schedule the spu_dma_work and the spu_dma_work could also arm the dreamcastcard->timer. When the snd_pcm_substream is closing, the aica_channel will be deallocated. But it could still be dereferenced in the worker thread. The reason is that del_timer() will return directly regardless of whether the timer handler is running or not and the worker could be rescheduled in the timer handler. As a result, the UAF bug will happen. The racy situation is shown below: (Thread 1) | (Thread 2) snd_aicapcm_pcm_close() | ... | run_spu_dma() //worker | mod_timer() flush_work() | del_timer() | aica_period_elapsed() //timer kfree(dreamcastcard->channel) | schedule_work() | run_spu_dma() //worker ... | dreamcastcard->channel-> //USE In order to mitigate this bug and other possible corner cases, call mod_timer() conditionally in run_spu_dma(), then implement PCM sync_stop op to cancel both the timer and worker. The sync_stop op will be called from PCM core appropriately when needed.

Affected products

• Debian Debian Linux: version 10.0 only
• Linux Linux Kernel: from 2.6.23, before 4.19.312 (fixed in 4.19.312); from 4.20, before 5.4.274 (fixed in 5.4.274); from 5.5, before 5.10.215 (fixed in 5.10.215); from 5.11, before 5.15.154 (fixed in 5.15.154); from 5.16, before 6.1.84 (fixed in 6.1.84); from 6.2, before 6.6.24 (fixed in 6.6.24); …

Published 2024-04-01. Last modified 2026-08-04.