avcodec/shorten: clear bitstream buffer

Fixes use of uninitialized memory
Fixes: msan_uninit-mem_7f3ca95606fb_6393_luckynight-partial.shn
Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

diff --git a/libavcodec/shorten.c b/libavcodec/shorten.c
index 2bd35d2..8b91ed3 100644 (file)
--- a/libavcodec/shorten.c
+++ b/libavcodec/shorten.c
@@ -432,6 +432,7 @@ static int shorten_decode_frame(AVCodecContext *avctx, void *data,
             av_log(avctx, AV_LOG_ERROR, "error allocating bitstream buffer\n");
             return AVERROR(ENOMEM);
         }
+        memset(tmp_ptr, 0, s->allocated_bitstream_size);
         s->bitstream = tmp_ptr;
     }