[FFmpeg-cvslog] avformat/wtvdec: Fix signed integer overflow

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Tue Sep 12 13:46:25 2023 +0200| [78169f397dad3d9af9cd750441e11b7e201e3949] | committer: Andreas Rheinhardt

avformat/wtvdec: Fix signed integer overflow

Happens when length > INT_MAX / 2; use unsigned for the computation,
but restrict the value to INT_MAX, because avio_get_str16le()
accepts an int as buf_len argument. Notice that it can happen
that the string read by avio_get_str16le() is truncated in this case.

Reviewed-by: Peter Ross <pross at xvid.org>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=78169f397dad3d9af9cd750441e11b7e201e3949
---

 libavformat/wtvdec.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libavformat/wtvdec.c b/libavformat/wtvdec.c
index 2de6dc2103..4ce4b6403e 100644
--- a/libavformat/wtvdec.c
+++ b/libavformat/wtvdec.c
@@ -468,7 +468,7 @@ static void get_tag(AVFormatContext *s, AVIOContext *pb, const char *key, int ty
         return;
     }
 
-    buf_size = FFMAX(2*length, LEN_PRETTY_GUID) + 1;
+    buf_size = FFMIN(FFMAX(2U * length, LEN_PRETTY_GUID) + 1, INT_MAX);
     buf = av_malloc(buf_size);
     if (!buf)
         return;