cx24116: fix a buffer overflow when checking userspace params

commit 1fa2337a315a2448c5434f41e00d56b01a22283c upstream.

The maximum size for a DiSEqC command is 6, according to the
userspace API. However, the code allows to write up much more values:
	drivers/media/dvb-frontends/cx24116.c:983 cx24116_send_diseqc_msg() error: buffer overflow 'd->msg' 6 <= 23

Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Mauro Carvalho Chehab 2015-04-28 18:51:17 -03:00 committed by Greg Kroah-Hartman
parent 72a5986b35
commit 81afd3a2f3
1 changed files with 4 additions and 4 deletions

View File

@ -963,6 +963,10 @@ static int cx24116_send_diseqc_msg(struct dvb_frontend *fe,
struct cx24116_state *state = fe->demodulator_priv;
int i, ret;
/* Validate length */
if (d->msg_len > sizeof(d->msg))
return -EINVAL;
/* Dump DiSEqC message */
if (debug) {
printk(KERN_INFO "cx24116: %s(", __func__);
@ -974,10 +978,6 @@ static int cx24116_send_diseqc_msg(struct dvb_frontend *fe,
printk(") toneburst=%d\n", toneburst);
}
/* Validate length */
if (d->msg_len > (CX24116_ARGLEN - CX24116_DISEQC_MSGOFS))
return -EINVAL;
/* DiSEqC message */
for (i = 0; i < d->msg_len; i++)
state->dsec_cmd.args[CX24116_DISEQC_MSGOFS + i] = d->msg[i];