Fix potential zero-length VLA

lib/upipe-ts/upipe_ts_pmt_decoder.c

@@ -635,7 +635,8 @@ static int upipe_ts_pmtd_parse_descs(struct upipe *upipe,
     const uint8_t *desc;
     int j = 0;
 
-    uint8_t descl_copy[desclength];
+    /* desclength can be zero and VLA must be greater than zero */
+    uint8_t descl_copy[desclength + 1];
     uint16_t copy_len = 0;
 
     /* cast needed because biTStream expects an uint8_t * (but doesn't write

lib/upipe/ubuf_pic_mem.c

@@ -146,8 +146,9 @@ static struct ubuf *ubuf_pic_mem_alloc(struct ubuf_mgr *mgr,
 
     size_t hmsize = hsize / pic_mgr->common_mgr.macropixel;
     size_t buffer_size = 0;
-    size_t plane_sizes[pic_mgr->common_mgr.nb_planes];
-    size_t strides[pic_mgr->common_mgr.nb_planes];
+    /* nb_planes can be zero and VLA must be greater than zero */
+    size_t plane_sizes[pic_mgr->common_mgr.nb_planes + 1];
+    size_t strides[pic_mgr->common_mgr.nb_planes + 1];
     for (uint8_t plane = 0; plane < pic_mgr->common_mgr.nb_planes; plane++) {
         size_t align = 0;
         if (pic_mgr->align &&

lib/upipe/ubuf_sound_mem.c

@@ -127,7 +127,8 @@ static struct ubuf *ubuf_sound_mem_alloc(struct ubuf_mgr *mgr,
     }
 
     size_t buffer_size = 0;
-    size_t plane_sizes[sound_mgr->common_mgr.nb_planes];
+    /* nb_planes can be zero and VLA must be greater than zero */
+    size_t plane_sizes[sound_mgr->common_mgr.nb_planes + 1];
     for (uint8_t plane = 0; plane < sound_mgr->common_mgr.nb_planes; plane++) {
         size_t align = 0;
         size_t plane_size;