File audio-fix-wavcapture-segfault.patch of Package qemu.21548

From: Bruce Rogers <brogers@suse.com>
Date: Thu, 21 May 2020 11:29:31 -0600
Subject: audio: fix wavcapture segfault
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

Git-commit: cbaf25d1f59ee13fc7542a06ea70784f2e000c04
References: boo#1171712

Commit 571a8c522e caused the HMP wavcapture command to segfault when
processing audio data in audio_pcm_sw_write(), where a NULL
sw->hw->pcm_ops is dereferenced. This fix checks that the pointer is
valid before dereferincing it. A similar fix is also made in the
parallel function audio_pcm_sw_read().

Fixes: 571a8c522e (audio: split ctl_* functions into enable_* and
volume_*)
Signed-off-by: Bruce Rogers <brogers@suse.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-id: 20200521172931.121903-1-brogers@suse.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Bruce Rogers <brogers@suse.com>
---
 audio/audio.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/audio/audio.c b/audio/audio.c
index 56fae55047103af9fb85aa47c905..566febf7d76eba61e4db472d0fd1 100644
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -634,7 +634,7 @@ static size_t audio_pcm_sw_read(SWVoiceIn *sw, void *buf, size_t size)
         total += isamp;
     }
 
-    if (!hw->pcm_ops->volume_in) {
+    if (hw->pcm_ops && !hw->pcm_ops->volume_in) {
         mixeng_volume (sw->buf, ret, &sw->vol);
     }
 
@@ -721,7 +721,7 @@ static size_t audio_pcm_sw_write(SWVoiceOut *sw, void *buf, size_t size)
     if (swlim) {
         sw->conv (sw->buf, buf, swlim);
 
-        if (!sw->hw->pcm_ops->volume_out) {
+        if (sw->hw->pcm_ops && !sw->hw->pcm_ops->volume_out) {
             mixeng_volume (sw->buf, swlim, &sw->vol);
         }
     }