media: technisat-usb2: break out of loop at end of buffer

Ensure we do not access the buffer beyond the end if no 0xff byte
is encountered.

Reported-by: syzbot+eaaaf38a95427be88f4b@syzkaller.appspotmail.com
Signed-off-by: Sean Young <sean@mess.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
This commit is contained in:
Sean Young 2019-07-03 10:52:39 -04:00 коммит произвёл Mauro Carvalho Chehab
Родитель 5dd4b89dc0
Коммит 0c4df39e50
1 изменённых файлов: 10 добавлений и 12 удалений

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@ -608,10 +608,9 @@ static int technisat_usb2_frontend_attach(struct dvb_usb_adapter *a)
static int technisat_usb2_get_ir(struct dvb_usb_device *d)
{
struct technisat_usb2_state *state = d->priv;
u8 *buf = state->buf;
u8 *b;
int ret;
struct ir_raw_event ev;
u8 *buf = state->buf;
int i, ret;
buf[0] = GET_IR_DATA_VENDOR_REQUEST;
buf[1] = 0x08;
@ -647,26 +646,25 @@ unlock:
return 0; /* no key pressed */
/* decoding */
b = buf+1;
#if 0
deb_rc("RC: %d ", ret);
debug_dump(b, ret, deb_rc);
debug_dump(buf + 1, ret, deb_rc);
#endif
ev.pulse = 0;
while (1) {
ev.pulse = !ev.pulse;
ev.duration = (*b * FIRMWARE_CLOCK_DIVISOR * FIRMWARE_CLOCK_TICK) / 1000;
ir_raw_event_store(d->rc_dev, &ev);
b++;
if (*b == 0xff) {
for (i = 1; i < ARRAY_SIZE(state->buf); i++) {
if (buf[i] == 0xff) {
ev.pulse = 0;
ev.duration = 888888*2;
ir_raw_event_store(d->rc_dev, &ev);
break;
}
ev.pulse = !ev.pulse;
ev.duration = (buf[i] * FIRMWARE_CLOCK_DIVISOR *
FIRMWARE_CLOCK_TICK) / 1000;
ir_raw_event_store(d->rc_dev, &ev);
}
ir_raw_event_handle(d->rc_dev);