[FFmpeg-cvslog] avformat/dhav: Check amount read

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Wed May 22 06:57:19 2024 +0200| [d8cad01805be74783344d69e81c9c31f49ba4d92] | committer: Andreas Rheinhardt

avformat/dhav: Check amount read

Prevents potential use of uninitialized data in the following
memcmp().

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=d8cad01805be74783344d69e81c9c31f49ba4d92
---

 libavformat/dhav.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libavformat/dhav.c b/libavformat/dhav.c
index 8e08274e68..b2ead99609 100644
--- a/libavformat/dhav.c
+++ b/libavformat/dhav.c
@@ -278,7 +278,9 @@ static int dhav_read_header(AVFormatContext *s)
     if (ret < 0)
         return ret;
 
-    avio_read(s->pb, signature, sizeof(signature));
+    ret = ffio_read_size(s->pb, signature, sizeof(signature));
+    if (ret < 0)
+        return ret;
     if (!memcmp(signature, "DAHUA", 5)) {
         avio_skip(s->pb, 0x400 - 5);
         dhav->last_good_pos = avio_tell(s->pb);