[FFmpeg-devel] [PATCH] avcodec/faxcompr: Check for end of bitstream in decode_group3_1d_line() and decode_group3_2d_line()
Michael Niedermayer
michael at niedermayer.cc
Thu Apr 29 18:13:58 EEST 2021
Fixes: infinite loop
Fixes: 33674/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-4816457818046464
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 | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/libavcodec/faxcompr.c b/libavcodec/faxcompr.c
index 7bf11d80ca..1fc4aca0b3 100644
--- a/libavcodec/faxcompr.c
+++ b/libavcodec/faxcompr.c
@@ -209,6 +209,8 @@ static int decode_group3_1d_line(AVCodecContext *avctx, GetBitContext *gb,
unsigned int run = 0;
unsigned int t;
for (;;) {
+ if (get_bits_left(gb) <= 0)
+ return AVERROR_INVALIDDATA;
t = get_vlc2(gb, ccitt_vlc[mode].table, 9, 2);
run += t;
if (t < 64) {
@@ -254,6 +256,8 @@ static int decode_group3_2d_line(AVCodecContext *avctx, GetBitContext *gb,
unsigned int offs = 0, run = 0;
while (offs < width) {
+ if (get_bits_left(gb) <= 0)
+ return AVERROR_INVALIDDATA;
int cmode = get_vlc2(gb, ccitt_group3_2d_vlc.table, 9, 1);
if (cmode == -1) {
av_log(avctx, AV_LOG_ERROR, "Incorrect mode VLC\n");
--
2.17.1
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