From: Mauro Carvalho Chehab Date: Tue, 28 Apr 2015 21:51:17 +0000 (-0300) Subject: [media] cx24116: fix a buffer overflow when checking userspace params X-Git-Tag: v4.2-rc1~107^2~510 X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=1fa2337a315a2448c5434f41e00d56b01a22283c;p=karo-tx-linux.git [media] cx24116: fix a buffer overflow when checking userspace params 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 Cc: stable@vger.kernel.org Signed-off-by: Mauro Carvalho Chehab --- diff --git a/drivers/media/dvb-frontends/cx24116.c b/drivers/media/dvb-frontends/cx24116.c index 2916d7c74a1d..7bc68b355c0b 100644 --- a/drivers/media/dvb-frontends/cx24116.c +++ b/drivers/media/dvb-frontends/cx24116.c @@ -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];