flacdec: simplify bounds checking in flac_probe()

Simplify `p->buf > p->buf + p->buf_size - 4' as `p->buf_size < 4'.
Avoid a possible out-of-bounds pointer, which is undefined behavior
in C.

CC: libav-stable@libav.org

Signed-off-by: Xi Wang <xi.wang@gmail.com>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

(cherry picked from commit 8425d693ee)
This commit is contained in:
Xi Wang 2013-03-15 07:11:47 -04:00 committed by Luca Barbato
parent 0b0e87bb54
commit 9d4355d90a

View File

@ -278,11 +278,9 @@ static int flac_read_header(AVFormatContext *s)
static int flac_probe(AVProbeData *p)
{
uint8_t *bufptr = p->buf;
uint8_t *end = p->buf + p->buf_size;
if(bufptr > end-4 || memcmp(bufptr, "fLaC", 4)) return 0;
else return AVPROBE_SCORE_MAX/2;
if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4))
return 0;
return AVPROBE_SCORE_MAX/2;
}
AVInputFormat ff_flac_demuxer = {