[FFmpeg-cvslog] avcodec/ffv1dec: Fix integer overflow in read_quant_table()

[Michael Niedermayer]

ffmpeg | branch: release/3.3 | Michael Niedermayer <michael at niedermayer.cc> | Mon Sep 18 17:26:09 2017 +0200| [6d1ebb9def18ee95f08fa63428d31b9742809e21] | committer: Michael Niedermayer

avcodec/ffv1dec: Fix integer overflow in read_quant_table()

Fixes: runtime error: signed integer overflow: 2147483647 + 1 cannot be represented in type 'int'
Fixes: 3361/clusterfuzz-testcase-minimized-5065842955911168

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
(cherry picked from commit d00fc952b6c261dd8eb0f7552b9ccf985dbc2b20)
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=6d1ebb9def18ee95f08fa63428d31b9742809e21
---

 libavcodec/ffv1dec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavcodec/ffv1dec.c b/libavcodec/ffv1dec.c
index 20921c6adf..8a0a82e62b 100644
--- a/libavcodec/ffv1dec.c
+++ b/libavcodec/ffv1dec.c
@@ -354,7 +354,7 @@ static int read_quant_table(RangeCoder *c, int16_t *quant_table, int scale)
     memset(state, 128, sizeof(state));
 
     for (v = 0; i < 128; v++) {
-        unsigned len = get_symbol(c, state, 0) + 1;
+        unsigned len = get_symbol(c, state, 0) + 1U;
 
         if (len > 128 - i || !len)
             return AVERROR_INVALIDDATA;