avcodec/mjpegdec: check len in mjpeg_decode_app() more completely

Avoids len from becoming negative and causing assertion failure

Fixes: signal_sigabrt_7ffff7126425_5140_fd44dc63fa7bdd12ee34fc602231ef02.jpg

Found-by: Mateusz "j00ru" Jurczyk and Gynvael Coldwind
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
(cherry picked from commit 6060234d43dcf0b5200cdd7dbd2f1542146827eb)

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-11-22 16:51:07 +01:00
parent 898ab02557
commit d1a9195863

View File

@ -1444,7 +1444,7 @@ static int mjpeg_decode_app(MJpegDecodeContext *s)
int len, id, i;
len = get_bits(&s->gb, 16);
if (len < 5)
if (len < 6)
return AVERROR_INVALIDDATA;
if (8 * len > get_bits_left(&s->gb))
return AVERROR_INVALIDDATA;
@ -1558,7 +1558,7 @@ static int mjpeg_decode_app(MJpegDecodeContext *s)
}
/* EXIF metadata */
if (s->start_code == APP1 && id == AV_RB32("Exif")) {
if (s->start_code == APP1 && id == AV_RB32("Exif") && len >= 2) {
GetByteContext gbytes;
int ret, le, ifd_offset, bytes_read;
const uint8_t *aligned;