avcodec/ac3: Explicitly return to discard large amounts of nonsense bytes

Changes 19sec to 10ms (12559) runtime, 17sec to 177ms (12570) Fixes: Timeout Fixes: 12559/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AC3_fuzzer-5666516266123264 Fixes: 12561/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_AC3_FIXED_fuzzer-5682923041193984 Fixes: 12570/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_EAC3_fuzzer-5194734308425728 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
6 years ago · 1e59071aad
parent 835ab35ef0
commit 1e59071aad
1 changed files with 2 additions and 0 deletions
--- a/libavcodec/ac3dec.c
+++ b/libavcodec/ac3dec.c
@ -1490,6 +1490,8 @@ static int ac3_decode_frame(AVCodecContext * avctx, void *data,
    }
    if (i >= buf_size)
        return AVERROR_INVALIDDATA;
+    if (i > 10)
+        return i;
    buf += i;
    buf_size -= i;