[FFmpeg-cvslog] avcodec/vp6: return value check for av_mallocz

[Jiasheng Jiang]

ffmpeg | branch: master | Jiasheng Jiang <jiasheng at iscas.ac.cn> | Mon Feb  7 11:44:53 2022 +0800| [c4d63dbc9417ddf77f6e33f6144b23da7e97cb3b] | committer: Peter Ross

avcodec/vp6: return value check for av_mallocz

As the potential failure of the av_mallocz(), the 's->alpha_context'
could be NULL and be dereferenced later.
Therefore, it should be better to check it and deal with it if fails
in order to prevent memory leak, same as the av_frame_alloc() in
ff_vp56_init().

Fixes: 39a3894ad5 ("lavc/vp6: Implement "slice" threading for VP6A decode")
Reviewed-by: Peter Ross <pross at xvid.org>
Signed-off-by: Jiasheng Jiang <jiasheng at iscas.ac.cn>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=c4d63dbc9417ddf77f6e33f6144b23da7e97cb3b
---

 libavcodec/vp6.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/vp6.c b/libavcodec/vp6.c
index d024370793..d75e717082 100644
--- a/libavcodec/vp6.c
+++ b/libavcodec/vp6.c
@@ -653,6 +653,10 @@ static av_cold int vp6_decode_init(AVCodecContext *avctx)
 
     if (s->has_alpha) {
         s->alpha_context = av_mallocz(sizeof(VP56Context));
+        if (!s->alpha_context) {
+            ff_vp56_free(avctx);
+            return AVERROR(ENOMEM);
+        }
         ff_vp56_init_context(avctx, s->alpha_context,
                              s->flip == -1, s->has_alpha);
         ff_vp6dsp_init(&s->alpha_context->vp56dsp);