audio: fix SIGSEGV in AUD_get_buffer_size_out()

As far as the emulated audio devices are concerned the pointer
returned by AUD_open_out() is an opaque handle. This includes
the NULL pointer. In this case, AUD_get_buffer_size_out() should
return a sensible buffer size instead of triggering a segmentation
fault. All other public AUD_*_out() and audio_*_out() functions
handle this case.

Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Signed-off-by: Volker Rümelin <vr_qemu@t-online.de>
Message-Id: <20250515054429.7385-2-vr_qemu@t-online.de>
(cherry picked from commit 5ddd6c8dc849b4af44bd06840c9133d64e62c27c)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

diff --git a/audio/audio.c b/audio/audio.c
index 065602ce1b9598fd09953ad14b16bbdb07be87c6..0caf41fff64ee13fad0dee34f2de69038328425e 100644 (file)
--- a/audio/audio.c
+++ b/audio/audio.c
@@ -894,6 +894,10 @@ size_t AUD_read(SWVoiceIn *sw, void *buf, size_t size)
 
 int AUD_get_buffer_size_out(SWVoiceOut *sw)
 {
+    if (!sw) {
+        return 0;
+    }
+
     return sw->hw->samples * sw->hw->info.bytes_per_frame;
 }