In the Linux kernel, the following vulnerability has been resolved: ALSA: pcm: oss: Fix setup list UAF on proc write error snd_pcm_oss_pro

In the Linux kernel, the following vulnerability has been resolved:

ALSA: pcm: oss: Fix setup list UAF on proc write error

snd_pcm_oss_proc_write() links a newly allocated setup entry into the
OSS setup list before duplicating the task name. If the task-name
allocation fails, the error path frees the already linked entry and
leaves setup_list pointing at freed memory.

A later OSS device open can then walk the stale list entry in
snd_pcm_oss_look_for_setup() and dereference freed memory.

Allocate the task name and initialize the setup entry before publishing
the entry on setup_list. Also fetch the initial proc read iterator only
after taking setup_mutex, so all setup_list traversal follows the same
list lifetime rules.