4xmdec: fix integer overflow, null ptr dereference

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
12 years ago · aed128f07d
parent ed27ed9f4f
commit aed128f07d
1 changed files with 1 additions and 1 deletions
--- a/libavcodec/4xm.c
+++ b/libavcodec/4xm.c
@ -428,7 +428,7 @@ static int decode_p_frame(FourXContext *f, const uint8_t *buf, int length)
        bytestream_size = FFMAX(length - bitstream_size - wordstream_size, 0);
    }

-    if (bitstream_size > length ||
+    if (bitstream_size > length || bitstream_size >= INT_MAX/8 ||
        bytestream_size > length - bitstream_size ||
        wordstream_size > length - bytestream_size - bitstream_size ||
        extra > length - bytestream_size - bitstream_size - wordstream_size) {