[FFmpeg-devel] [PATCH 2/3] avcodec/faxcompr: Check if bits are available before reading in cmode == 9 || cmode == 10
Michael Niedermayer
michael at niedermayer.cc
Thu Jun 10 16:58:10 EEST 2021
Fixes: Timeout
Fixes: 34950/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-5686764151898112
Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
libavcodec/faxcompr.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/libavcodec/faxcompr.c b/libavcodec/faxcompr.c
index d44de2485d..45e0c482d7 100644
--- a/libavcodec/faxcompr.c
+++ b/libavcodec/faxcompr.c
@@ -304,7 +304,10 @@ static int decode_group3_2d_line(AVCodecContext *avctx, GetBitContext *gb,
mode = !mode;
}
} else if (cmode == 9 || cmode == 10) {
- int xxx = get_bits(gb, 3);
+ int xxx;
+ if (get_bits_left(gb) < 3)
+ return AVERROR_INVALIDDATA;
+ xxx = get_bits(gb, 3);
if (cmode == 9 && xxx == 7) {
int ret;
int pix_left = width - offs;
--
2.17.1
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