avcodec/diracdec: Check slices malloc and propagate error code

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit a4d3cf10)
Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>

libavcodec/diracdec.c

@@ -772,7 +772,7 @@ static int decode_lowdelay_slice(AVCodecContext *avctx, void *arg)
  * Dirac Specification ->
  * 13.5.1 low_delay_transform_data()
  */
-static void decode_lowdelay(DiracContext *s)
+static int decode_lowdelay(DiracContext *s)
 {
     AVCodecContext *avctx = s->avctx;
     int slice_x, slice_y, bytes, bufsize;
@@ -781,6 +781,8 @@ static void decode_lowdelay(DiracContext *s)
     int slice_num = 0;
 
     slices = av_mallocz_array(s->lowdelay.num_x, s->lowdelay.num_y * sizeof(struct lowdelay_slice));
+    if (!slices)
+        return AVERROR(ENOMEM);
 
     align_get_bits(&s->gb);
     /*[DIRAC_STD] 13.5.2 Slices. slice(sx,sy) */
@@ -811,6 +813,7 @@ static void decode_lowdelay(DiracContext *s)
     intra_dc_prediction(&s->plane[1].band[0][0]);  /* [DIRAC_STD] 13.3 intra_dc_prediction() */
     intra_dc_prediction(&s->plane[2].band[0][0]);  /* [DIRAC_STD] 13.3 intra_dc_prediction() */
     av_free(slices);
+    return 0;
 }
 
 static void init_planes(DiracContext *s)
@@ -1606,6 +1609,7 @@ static int dirac_decode_frame_internal(DiracContext *s)
 {
     DWTContext d;
     int y, i, comp, dsty;
+    int ret;
 
     if (s->low_delay) {
         /* [DIRAC_STD] 13.5.1 low_delay_transform_data() */
@@ -1613,8 +1617,10 @@ static int dirac_decode_frame_internal(DiracContext *s)
             Plane *p = &s->plane[comp];
             memset(p->idwt_buf, 0, p->idwt_stride * p->idwt_height * sizeof(IDWTELEM));
         }
-        if (!s->zero_res)
-            decode_lowdelay(s);
+        if (!s->zero_res) {
+            if ((ret = decode_lowdelay(s)) < 0)
+                return ret;
+        }
     }
 
     for (comp = 0; comp < 3; comp++) {