[FFmpeg-cvslog] avcodec/lzw: Check for end of input

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Fri Jan 11 22:38:35 2019 +0100| [19dc5cdaa7c4a0e62c30497814417ffe77fb2ed7] | committer: Michael Niedermayer

avcodec/lzw: Check for end of input

Fixes: Timeout
Fixes: 11873/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_TIFF_fuzzer-5093495044308992

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=19dc5cdaa7c4a0e62c30497814417ffe77fb2ed7
---

 libavcodec/lzw.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/libavcodec/lzw.c b/libavcodec/lzw.c
index b0b9a34358..e26e4829ee 100644
--- a/libavcodec/lzw.c
+++ b/libavcodec/lzw.c
@@ -71,6 +71,9 @@ static int lzw_get_code(struct LZWState * s)
 {
     int c;
 
+    if (s->bbits < s->cursize && bytestream2_get_bytes_left(&s->gb) <= 0)
+        return s->end_code;
+
     if(s->mode == FF_LZW_GIF) {
         while (s->bbits < s->cursize) {
             if (!s->bs) {