CVE-2022-49733 Information

Description

In the Linux kernel the following vulnerability has been resolved:

ALSA: pcm: oss: Fix race at SNDCTL_DSP_SYNC

There is a small race window at snd_pcm_oss_sync() that is called from OSS PCM SNDCTL_DSP_SYNC ioctl; namely the function calls snd_pcm_oss_make_ready() at first then takes the params_lock mutex for the rest. When the stream is set up again by another thread between them it leads to inconsistency and may result in unexpected results such as NULL dereference of OSS buffer as a fuzzer spotted recently.

The fix is simply to cover snd_pcm_oss_make_ready() call into the same params_lock mutex with snd_pcm_oss_make_ready_locked() variant.

Reference

https://git.kernel.org/stable/c/4051324a6dafd7053c74c475e80b3ba10ae672b0 https://git.kernel.org/stable/c/723ac5ab2891b6c10dd6cc78ef5456af593490eb https://git.kernel.org/stable/c/8015ef9e8a0ee5cecfd0cb6805834d007ab26f86 https://git.kernel.org/stable/c/8423f0b6d513b259fdab9c9bf4aaa6188d054c2d https://git.kernel.org/stable/c/fce793a056c604b41a298317cf704dae255f1b36