avcodec/vp3: Check that there will be sufficient input for the coded fragments in...
authorMichael Niedermayer <michael@niedermayer.cc>
Sat, 5 May 2018 18:08:36 +0000 (20:08 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Sun, 13 May 2018 21:52:16 +0000 (23:52 +0200)
Fixes: Timeout
Fixes: 6292/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_VP3_fuzzer-4871218218926080

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/vp3.c

index 1d83753..2050090 100644 (file)
@@ -543,7 +543,10 @@ static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
                                          : s->y_superblock_count);
         int num_coded_frags = 0;
 
-        for (i = sb_start; i < sb_end && get_bits_left(gb) > 0; i++) {
+        for (i = sb_start; i < sb_end; i++) {
+            if (get_bits_left(gb) < ((s->total_num_coded_frags + num_coded_frags) >> 2)) {
+                return AVERROR_INVALIDDATA;
+            }
             /* iterate through all 16 fragments in a superblock */
             for (j = 0; j < 16; j++) {
                 /* if the fragment is in bounds, check its coding status */