Re: [PATCH 0/4] ALSA: pcm: Fix ioctl races

On 22. 03. 22 18:07, Takashi Iwai wrote:

Hi,

this is a patch set to address the recently reported bug for the racy PCM ioctls. In short, the current ALSA PCM core doesn't take enough care of concurrent ioctl calls, and the concurrent calls may result in a use-after-free. The reported problem was the concurrent hw_free calls, but there can be similar cases with other code paths like hw_params, prepare, etc, too.

The patch set introduces the new runtime->buffer_mutex for protecting those. The first patch is the fix for the reported issue (the races with hw_free), while the rest three are more hardening for the other similar executions.

Thank you Takashi.

Reviewed-by: Jaroslav Kysela perex@perex.cz