The true problem happens in several previous get_vlc_symbol() but checking that is more expensive (involving FFABS()) here its just a simple check between 2 variables we have.
Fixes: Assertion log >= k failed at libavcodec/golomb.h:406 Fixes: 429296194/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_FFV1_DEC_fuzzer-4691594622337024 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> --- libavcodec/ffv1dec.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c index d613aa53959..d709e8ccbb3 100644 --- a/libavcodec/ffv1dec.c +++ b/libavcodec/ffv1dec.c @@ -56,6 +56,11 @@ static inline int get_vlc_symbol(GetBitContext *gb, VlcState *const state, k++; i += i; } + if (k > bits) { + ff_dlog(NULL, "k-overflow bias:%d error:%d drift:%d count:%d k:%d", + state->bias, state->error_sum, state->drift, state->count, k); + k = bits; + } v = get_sr_golomb(gb, k, 12, bits); ff_dlog(NULL, "v:%d bias:%d error:%d drift:%d count:%d k:%d", -- 2.49.0 _______________________________________________ ffmpeg-devel mailing list ffmpeg-devel@ffmpeg.org https://ffmpeg.org/mailman/listinfo/ffmpeg-devel To unsubscribe, visit link above, or email ffmpeg-devel-requ...@ffmpeg.org with subject "unsubscribe".
