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

BugLink: http://bugs.launchpad.net/bugs/1745266
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.

Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/sound/core/oss/pcm_plugin.c b/sound/core/oss/pcm_plugin.c
index 727ac44d39f4a64f7ba203d8dd839caaa66c15ec..a84a1d3d23e56e15c20710c221dfc52a6a743437 100644 (file)
--- a/sound/core/oss/pcm_plugin.c
+++ b/sound/core/oss/pcm_plugin.c
@@ -591,18 +591,26 @@ 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;