wtv: Add more sanity checks for a length read from the file
authorMartin Storsjö <martin@martin.st>
Thu, 19 Sep 2013 13:55:13 +0000 (16:55 +0300)
committerLuca Barbato <lu_zero@gentoo.org>
Fri, 4 Oct 2013 01:26:28 +0000 (03:26 +0200)
Also make sure the existing length check can't overflow.

Reported-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
CC: libav-stable@libav.org
Signed-off-by: Martin Storsjö <martin@martin.st>
(cherry picked from commit 83c285f88016b087c2f0f4b9ef356ad8ef12d947)
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
libavformat/wtv.c

index 1811e46..7f029ff 100644 (file)
@@ -274,7 +274,12 @@ static AVIOContext * wtvfile_open2(AVFormatContext *s, const uint8_t *buf, int b
         dir_length  = AV_RL16(buf + 16);
         file_length = AV_RL64(buf + 24);
         name_size   = 2 * AV_RL32(buf + 32);
-        if (buf + 48 + name_size > buf_end) {
+        if (name_size < 0) {
+            av_log(s, AV_LOG_ERROR,
+                   "bad filename length, remaining directory entries ignored\n");
+            break;
+        }
+        if (48 + name_size > buf_end - buf) {
             av_log(s, AV_LOG_ERROR, "filename exceeds buffer size; remaining directory entries ignored\n");
             break;
         }