Patch "ALSA: pcm: Add missing error checks in OSS emulation plugin builder" has been added to the 4.9-stable tree

This is a note to let you know that I've just added the patch titled

ALSA: pcm: Add missing error checks in OSS emulation plugin builder

to the 4.9-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
alsa-pcm-add-missing-error-checks-in-oss-emulation-plugin-builder.patch
and it can be found in the queue-4.9 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Takashi Iwai <[email protected]>
Date: Thu, 4 Jan 2018 16:39:27 +0100
Subject: ALSA: pcm: Add missing error checks in OSS emulation plugin builder

From: Takashi Iwai <[email protected]>

commit 6708913750344a900f2e73bfe4a4d6dbbce4fe8d upstream.

In the OSS emulation plugin builder where the frame size is parsed in the plugin chain, some places miss the possible errors returned from the plugin src_ or dst_frames callback.

This patch papers over such places.

---
 sound/core/oss/pcm_plugin.c |   14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

@@ -591,18 +591,26 @@ snd_pcm_sframes_t snd_pcm_plug_write_tra
 	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;

Patches currently in stable-queue which might be from [email protected] are

queue-4.9/alsa-pcm-remove-incorrect-snd_bug_on-usages.patch queue-4.9/alsa-aloop-fix-inconsistent-format-due-to-incomplete-rule.patch queue-4.9/alsa-pcm-add-missing-error-checks-in-oss-emulation-plugin-builder.patch queue-4.9/alsa-pcm-abort-properly-at-pending-signal-in-oss-read-write-loops.patch queue-4.9/alsa-pcm-allow-aborting-mutex-lock-at-oss-read-write-loops.patch queue-4.9/alsa-aloop-fix-racy-hw-constraints-adjustment.patch queue-4.9/alsa-aloop-release-cable-upon-open-error-path.patch