avcodec/diracdec: Check bytes count in else branch in decode_lowdelay() too
authorMichael Niedermayer <michael@niedermayer.cc>
Sun, 22 Jul 2018 19:42:16 +0000 (21:42 +0200)
committerMichael Niedermayer <michael@niedermayer.cc>
Mon, 22 Oct 2018 23:44:40 +0000 (01:44 +0200)
Fixes: signed integer overflow: 8 * 340018243 cannot be represented in type 'int'
Fixes: 9441/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_DIRAC_fuzzer-5194665207791616

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit bed125b7108481574f36fdd6ee699b27354602e8)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
libavcodec/diracdec.c

index d678363..272f2b4 100644 (file)
@@ -906,6 +906,10 @@ static int decode_lowdelay(DiracContext *s)
             for (slice_x = 0; bufsize > 0 && slice_x < s->num_x; slice_x++) {
                 bytes = (slice_num+1) * (int64_t)s->lowdelay.bytes.num / s->lowdelay.bytes.den
                        - slice_num    * (int64_t)s->lowdelay.bytes.num / s->lowdelay.bytes.den;
+                if (bytes >= INT_MAX || bytes*8 > bufsize) {
+                    av_log(s->avctx, AV_LOG_ERROR, "too many bytes\n");
+                    return AVERROR_INVALIDDATA;
+                }
                 slices[slice_num].bytes   = bytes;
                 slices[slice_num].slice_x = slice_x;
                 slices[slice_num].slice_y = slice_y;