[patch -next] wan/fsl_ucc_hdlc: info leak in uhdlc_ioctl()

There is a 2 byte struct whole after line.loopback so we need to clear
that out to avoid disclosing stack information.

Fixes: c19b6d246a35 ('drivers/net: support hdlc function for QE-UCC')
Signed-off-by: Dan Carpenter <redacted>

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index 19174ac..7608561 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c

@@ -635,6 +635,7 @@ static int uhdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 			ifr->ifr_settings.size = size; /* data size wanted */
 			return -ENOBUFS;
 		}
+		memset(&line, 0, sizeof(line));
 		line.clock_type = priv->clocking;
 		line.clock_rate = 0;
 		line.loopback = 0;

Am 14.07.2016 12:34, schrieb Dan Carpenter:

In this case
  		line.clock_rate = 0;
 		line.loopback = 0;

are not need any more and can be removed
except like them to have for documentation or so.

re,
 wh

There is a 2 byte struct whole after line.loopback so we need to clear
that out to avoid disclosing stack information.

Fixes: c19b6d246a35 ('drivers/net: support hdlc function for QE-UCC')
Signed-off-by: Dan Carpenter <redacted>
---
v2: remove the other initialization to zero

diff --git a/drivers/net/wan/fsl_ucc_hdlc.c b/drivers/net/wan/fsl_ucc_hdlc.c
index 19174ac..6edd48a 100644
--- a/drivers/net/wan/fsl_ucc_hdlc.c
+++ b/drivers/net/wan/fsl_ucc_hdlc.c

@@ -635,9 +635,8 @@ static int uhdlc_ioctl(struct net_device *dev, struct ifreq *ifr, int cmd)
 			ifr->ifr_settings.size = size; /* data size wanted */
 			return -ENOBUFS;
 		}
+		memset(&line, 0, sizeof(line));
 		line.clock_type = priv->clocking;
-		line.clock_rate = 0;
-		line.loopback = 0;
 
 		if (copy_to_user(ifr->ifr_settings.ifs_ifsu.sync, &line, size))
 			return -EFAULT;

Good point.  Thanks.

regards,
dan carpenter

From: Dan Carpenter <redacted>
Date: Thu, 14 Jul 2016 14:16:53 +0300

There is a 2 byte struct whole after line.loopback so we need to clear
that out to avoid disclosing stack information.

Fixes: c19b6d246a35 ('drivers/net: support hdlc function for QE-UCC')
Signed-off-by: Dan Carpenter <redacted>
---
v2: remove the other initialization to zero

Applied.