ALSA: pcm core - add a safe check to the silence filling function

In situation when appl_ptr is far greater then hw_ptr, the hw_avail value
can be greater than buffer_size. Check for this.

Signed-off-by: Jaroslav Kysela <perex@perex.cz>

diff --git a/sound/core/pcm_lib.c b/sound/core/pcm_lib.c
index bcf95d3..e23e0e7 100644 (file)
--- a/sound/core/pcm_lib.c
+++ b/sound/core/pcm_lib.c
@@ -67,6 +67,8 @@ void snd_pcm_playback_silence(struct snd_pcm_substream *substream, snd_pcm_ufram
        } else {
                if (new_hw_ptr == ULONG_MAX) {  /* initialization */
                        snd_pcm_sframes_t avail = snd_pcm_playback_hw_avail(runtime);
+                       if (avail > runtime->buffer_size)
+                               avail = runtime->buffer_size;
                        runtime->silence_filled = avail > 0 ? avail : 0;
                        runtime->silence_start = (runtime->status->hw_ptr +
                                                  runtime->silence_filled) %