avfilter/buffer: Check for qp_table allocation failure

Fixes CID1271048
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavfilter/buffer.c

@@ -42,13 +42,19 @@ void ff_avfilter_default_free_buffer(AVFilterBuffer *ptr)
     av_free(ptr);
 }
 
-static void copy_video_props(AVFilterBufferRefVideoProps *dst, AVFilterBufferRefVideoProps *src) {
+static int copy_video_props(AVFilterBufferRefVideoProps *dst, AVFilterBufferRefVideoProps *src) {
     *dst = *src;
     if (src->qp_table) {
         int qsize = src->qp_table_size;
         dst->qp_table = av_malloc(qsize);
+        if (!dst->qp_table) {
+            av_log(NULL, AV_LOG_ERROR, "Failed to allocate qp_table\n");
+            dst->qp_table_size = 0;
+            return AVERROR(ENOMEM);
+        }
         memcpy(dst->qp_table, src->qp_table, qsize);
     }
+    return 0;
 }
 
 AVFilterBufferRef *avfilter_ref_buffer(AVFilterBufferRef *ref, int pmask)