An alternative would be to leave the context unchanged on failure of hls_slice_header()
Fixes: out of array access Fixes: NULL pointer dereference Fixes: 69584/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-5931086299856896 Fixes: 69724/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_HEVC_fuzzer-5104066422702080 Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg Signed-off-by: Michael Niedermayer <mich...@niedermayer.cc> --- libavcodec/hevc/hevcdec.c | 12 ++++++++---- 1 file changed, 8 insertions(+), 4 deletions(-) diff --git a/libavcodec/hevc/hevcdec.c b/libavcodec/hevc/hevcdec.c index 0e4b26dad3b..80d59ab1916 100644 --- a/libavcodec/hevc/hevcdec.c +++ b/libavcodec/hevc/hevcdec.c @@ -621,6 +621,10 @@ static int hls_slice_header(SliceHeader *sh, const HEVCContext *s, GetBitContext if (pps->dependent_slice_segments_enabled_flag) sh->dependent_slice_segment_flag = get_bits1(gb); + if (sh->dependent_slice_segment_flag && !s->slice_initialized) { + av_log(s->avctx, AV_LOG_ERROR, "dependent slice failed\n"); + return AVERROR_INVALIDDATA; + } slice_address_length = av_ceil_log2(sps->ctb_width * sps->ctb_height); @@ -893,9 +897,6 @@ static int hls_slice_header(SliceHeader *sh, const HEVCContext *s, GetBitContext } else { sh->slice_loop_filter_across_slices_enabled_flag = pps->seq_loop_filter_across_slices_enabled_flag; } - } else if (!s->slice_initialized) { - av_log(s->avctx, AV_LOG_ERROR, "Independent slice segment missing.\n"); - return AVERROR_INVALIDDATA; } sh->num_entry_point_offsets = 0; @@ -3155,8 +3156,11 @@ static int decode_slice(HEVCContext *s, const H2645NAL *nal, GetBitContext *gb) int ret; ret = hls_slice_header(&s->sh, s, gb); - if (ret < 0) + if (ret < 0) { + //The code is not capable to rewind from an error, the state now is inconsistant so we cannot use it on depandant slices + s->slice_initialized = 0; return ret; + } if ((s->avctx->skip_frame >= AVDISCARD_BIDIR && s->sh.slice_type == HEVC_SLICE_B) || (s->avctx->skip_frame >= AVDISCARD_NONINTRA && s->sh.slice_type != HEVC_SLICE_I) || -- 2.45.2 _______________________________________________ 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".
