[FFmpeg-devel] [PATCH] avcodec/golomb: Prevent shift by negative number

[Andreas Rheinhardt]

This happened in get_ue_golomb() if the cached bitstream reader was in
use, because there was no check to handle the case of the read value
not being in the range 0..8190.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>
---
 libavcodec/golomb.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libavcodec/golomb.h b/libavcodec/golomb.h
index 7fd46a91bd..5bfcfe085f 100644
--- a/libavcodec/golomb.h
+++ b/libavcodec/golomb.h
@@ -66,6 +66,10 @@ static inline int get_ue_golomb(GetBitContext *gb)
         return ff_ue_golomb_vlc_code[buf];
     } else {
         int log = 2 * av_log2(buf) - 31;
+        if (log < 0) {
+            av_log(NULL, AV_LOG_ERROR, "Invalid UE golomb code\n");
+            return AVERROR_INVALIDDATA;
+        }
         buf >>= log;
         buf--;
         skip_bits_long(gb, 32 - log);
-- 
2.20.1