Merge tag 'sound-4.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound

Pull sound fixes from Takashi Iwai:
 "A collection of the last-minute small PCM fixes:

   - A workaround for the recent regression wrt PulseAudio

   - Removal of spurious WARN_ON() that is triggered by syzkaller

   - Fixes for aloop, hardening racy accesses

   - Fixes in PCM OSS emulation wrt the unabortable loops that may cause
     RCU stall"

* tag 'sound-4.15-rc8' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound:
  ALSA: pcm: Allow aborting mutex lock at OSS read/write loops
  ALSA: pcm: Abort properly at pending signal in OSS read/write loops
  ALSA: aloop: Fix racy hw constraints adjustment
  ALSA: aloop: Fix inconsistent format due to incomplete rule
  ALSA: aloop: Release cable upon open error path
  ALSA: pcm: Workaround for weird PulseAudio behavior on rewind error
  ALSA: pcm: Add missing error checks in OSS emulation plugin builder
  ALSA: pcm: Remove incorrect snd_BUG_ON() usages

1 files changed, 11 insertions, 3 deletions

diff --git a/sound/core/oss/pcm_plugin.c b/sound/core/oss/pcm_plugin.c
index cadc93792868..85a56af104bd 100644
--- a/sound/core/oss/pcm_plugin.c
+++ b/sound/core/oss/pcm_plugin.c
@@ -592,18 +592,26 @@ snd_pcm_sframes_t snd_pcm_plug_write_transfer(struct snd_pcm_substream *plug, st
 	snd_pcm_sframes_t frames = size;
 
 	plugin = snd_pcm_plug_first(plug);
-	while (plugin && frames > 0) {
+	while (plugin) {
+		if (frames <= 0)
+			return frames;
 		if ((next = plugin->next) != NULL) {
 			snd_pcm_sframes_t frames1 = frames;
-			if (plugin->dst_frames)
+			if (plugin->dst_frames) {
 				frames1 = plugin->dst_frames(plugin, frames);
+				if (frames1 <= 0)
+					return frames1;
+			}
 			if ((err = next->client_channels(next, frames1, &dst_channels)) < 0) {
 				return err;
 			}
 			if (err != frames1) {
 				frames = err;
-				if (plugin->src_frames)
+				if (plugin->src_frames) {
 					frames = plugin->src_frames(plugin, frames1);
+					if (frames <= 0)
+						return frames;
+				}
 			}
 		} else
 			dst_channels = NULL;