avcodec/dnxhddec: Move mb height check out of non hr branch
authorMichael Niedermayer <michael@niedermayer.cc>
Wed, 26 Jul 2017 01:26:59 +0000 (03:26 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Thu, 27 Jul 2017 01:11:19 +0000 (03:11 +0200)
Fixes: out of array access
Fixes: poc.dnxhd

Found-by: Bingchang, Liu@VARAS of IIE
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 296debd213bd6dce7647cedd34eb64e5b94cdc92)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/dnxhddec.c

index 383e64c..7cb6a75 100644 (file)
@@ -298,14 +298,18 @@ static int dnxhd_decode_header(DNXHDContext *ctx, AVFrame *frame,
     if (ctx->mb_height > 68 && ff_dnxhd_check_header_prefix_hr(header_prefix)) {
         ctx->data_offset = 0x170 + (ctx->mb_height << 2);
     } else {
-        if (ctx->mb_height > 68 ||
-            (ctx->mb_height << frame->interlaced_frame) > (ctx->height + 15) >> 4) {
+        if (ctx->mb_height > 68) {
             av_log(ctx->avctx, AV_LOG_ERROR,
                    "mb height too big: %d\n", ctx->mb_height);
             return AVERROR_INVALIDDATA;
         }
         ctx->data_offset = 0x280;
     }
+    if ((ctx->mb_height << frame->interlaced_frame) > (ctx->height + 15) >> 4) {
+        av_log(ctx->avctx, AV_LOG_ERROR,
+                "mb height too big: %d\n", ctx->mb_height);
+        return AVERROR_INVALIDDATA;
+    }
 
     if (buf_size < ctx->data_offset) {
         av_log(ctx->avctx, AV_LOG_ERROR,