High · published May 27, 2026
In the Linux kernel, the following vulnerability has been resolved:
ALSA: aloop: Fix peer runtime UAF during format-change stop
loopback_check_format() may stop the capture side when playback starts
with parameters that no longer match a running capture stream. Commit
826af7fa62e3 ("ALSA: aloop: Fix racy access at PCM trigger") moved
the peer lookup under cable->lock, but the actual snd_pcm_stop() still
runs after dropping that lock.
A concurrent close can clear the capture entry from cable->streams[] and
detach or free its runtime while the playback trigger path still holds a
stale peer substream pointer.
Keep a per-cable count of in-flight peer stops before dropping
cable->lock, and make free_cable() wait for those stops before
detaching the runtime. This preserves the existing behavior while
making the peer runtime lifetime explicit.
| Product | Versions | Fixed in |
|---|---|---|
| linux/linux_kernel | ≥ 2.6.37, < 5.10.259 | 5.10.259 |
| linux/linux_kernel | ≥ 5.11, < 5.15.210 | 5.15.210 |
| linux/linux_kernel | ≥ 5.16, < 6.12.88 | 6.12.88 |
| linux/linux_kernel | ≥ 6.13, < 6.18.27 | 6.18.27 |
| linux/linux_kernel | ≥ 6.19, < 7.0.4 | 7.0.4 |
| linux/linux_kernel | all versions | — |