[pulseaudio-discuss] [PATCH] alsa-ucm: disallow null mdev argument into pa_alsa_open_mixer_by_name()

[Tanu Kaskinen]

On Wed, 2020-07-01 at 11:20 +0300, Eero Nurkkala wrote:
> It's possible for mdev to be NULL. In this case, an assert is taken
> in pa_alsa_open_mixer_by_name() with debug builds, and a crash with
> release builds. However, it's possible to bypass this trouble by taking
> the error path if mdev is NULL.
> 
> Reported-by: Jarkko Sankala <jarkko.sankala at offcode.fi>
> Signed-off-by: Eero Nurkkala <eero.nurkkala at offcode.fi>
> ---
>  src/modules/alsa/alsa-ucm.c | 2 +-
>  1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/src/modules/alsa/alsa-ucm.c b/src/modules/alsa/alsa-ucm.c
> index 1dfb0e08b..295286555 100644
> --- a/src/modules/alsa/alsa-ucm.c
> +++ b/src/modules/alsa/alsa-ucm.c
> @@ -942,7 +942,7 @@ static void probe_volumes(pa_hashmap *hash, bool is_sink, snd_pcm_t *pcm_handle,
>              mdev = mdev2;
>          }
>  
> -        if (!(mixer_handle = pa_alsa_open_mixer_by_name(mixers, mdev, true))) {
> +        if (mdev == NULL || !(mixer_handle = pa_alsa_open_mixer_by_name(mixers, mdev, true))) {
>              pa_log_error("Failed to find a working mixer device (%s).", mdev);
>              goto fail;
>          }

Thanks! I merged this, and fixed another NULL pointer issue in the same
function.

Note that all patches must go through GitLab merge requests, so patch
submissions through GitLab are preferred.
https://gitlab.freedesktop.org/pulseaudio/pulseaudio

-- 
Tanu

https://www.patreon.com/tanuk
https://liberapay.com/tanuk