[PATCH AUTOSEL 4.4 5/6] net: usb: pegasus: Proper error handing when setting pegasus' MAC address

[PATCH AUTOSEL 4.4 5/6] net: usb: pegasus: Proper error handing when setting pegasus' MAC address

[Sasha Levin]

From: Petko Manolov <petko.manolov@konsulko.com>

[ Upstream commit f30e25a9d1b25ac8d40071c4dc2679ad0fcdc55a ]

v2:

If reading the MAC address from eeprom fail don't throw an error, use randomly
generated MAC instead.  Either way the adapter will soldier on and the return
type of set_ethernet_addr() can be reverted to void.

v1:

Fix a bug in set_ethernet_addr() which does not take into account possible
errors (or partial reads) returned by its helpers.  This can potentially lead to
writing random data into device's MAC address registers.

Signed-off-by: Petko Manolov <petko.manolov@konsulko.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/usb/pegasus.c | 35 +++++++++++++++++++++++++++--------
 1 file changed, 27 insertions(+), 8 deletions(-)

diff --git a/drivers/net/usb/pegasus.c b/drivers/net/usb/pegasus.c
index 4f505eb4f422c..f17a6852c2106 100644
--- a/drivers/net/usb/pegasus.c
+++ b/drivers/net/usb/pegasus.c
@@ -362,28 +362,47 @@ fail:
 }
 #endif				/* PEGASUS_WRITE_EEPROM */
 
-static inline void get_node_id(pegasus_t *pegasus, __u8 *id)
+static inline int get_node_id(pegasus_t *pegasus, u8 *id)
 {
-	int i;
-	__u16 w16;
+	int i, ret;
+	u16 w16;
 
 	for (i = 0; i < 3; i++) {
-		read_eprom_word(pegasus, i, &w16);
+		ret = read_eprom_word(pegasus, i, &w16);
+		if (ret < 0)
+			return ret;
 		((__le16 *) id)[i] = cpu_to_le16(w16);
 	}
+
+	return 0;
 }
 
 static void set_ethernet_addr(pegasus_t *pegasus)
 {
-	__u8 node_id[6];
+	int ret;
+	u8 node_id[6];
 
 	if (pegasus->features & PEGASUS_II) {
-		get_registers(pegasus, 0x10, sizeof(node_id), node_id);
+		ret = get_registers(pegasus, 0x10, sizeof(node_id), node_id);
+		if (ret < 0)
+			goto err;
 	} else {
-		get_node_id(pegasus, node_id);
-		set_registers(pegasus, EthID, sizeof(node_id), node_id);
+		ret = get_node_id(pegasus, node_id);
+		if (ret < 0)
+			goto err;
+		ret = set_registers(pegasus, EthID, sizeof(node_id), node_id);
+		if (ret < 0)
+			goto err;
 	}
+
 	memcpy(pegasus->net->dev_addr, node_id, sizeof(node_id));
+
+	return;
+err:
+	eth_hw_addr_random(pegasus->net);
+	dev_info(&pegasus->intf->dev, "software assigned MAC address.\n");
+
+	return;
 }
 
 static inline int reset_mac(pegasus_t *pegasus)
-- 
2.25.1

[PATCH AUTOSEL 4.4 6/6] net: usb: rtl8150: set random MAC address when set_ethernet_addr() fails

[Sasha Levin]

From: Anant Thazhemadam <anant.thazhemadam@gmail.com>

[ Upstream commit f45a4248ea4cc13ed50618ff066849f9587226b2 ]

When get_registers() fails in set_ethernet_addr(),the uninitialized
value of node_id gets copied over as the address.
So, check the return value of get_registers().

If get_registers() executed successfully (i.e., it returns
sizeof(node_id)), copy over the MAC address using ether_addr_copy()
(instead of using memcpy()).

Else, if get_registers() failed instead, a randomly generated MAC
address is set as the MAC address instead.

Reported-by: syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com
Tested-by: syzbot+abbc768b560c84d92fd3@syzkaller.appspotmail.com
Acked-by: Petko Manolov <petkan@nucleusys.com>
Signed-off-by: Anant Thazhemadam <anant.thazhemadam@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/net/usb/rtl8150.c | 16 ++++++++++++----
 1 file changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/net/usb/rtl8150.c b/drivers/net/usb/rtl8150.c
index 58b1e18fdd64d..7230f1e8210ff 100644
--- a/drivers/net/usb/rtl8150.c
+++ b/drivers/net/usb/rtl8150.c
@@ -277,12 +277,20 @@ static int write_mii_word(rtl8150_t * dev, u8 phy, __u8 indx, u16 reg)
 		return 1;
 }
 
-static inline void set_ethernet_addr(rtl8150_t * dev)
+static void set_ethernet_addr(rtl8150_t *dev)
 {
-	u8 node_id[6];
+	u8 node_id[ETH_ALEN];
+	int ret;
+
+	ret = get_registers(dev, IDR, sizeof(node_id), node_id);
 
-	get_registers(dev, IDR, sizeof(node_id), node_id);
-	memcpy(dev->netdev->dev_addr, node_id, sizeof(node_id));
+	if (ret == sizeof(node_id)) {
+		ether_addr_copy(dev->netdev->dev_addr, node_id);
+	} else {
+		eth_hw_addr_random(dev->netdev);
+		netdev_notice(dev->netdev, "Assigned a random MAC address: %pM\n",
+			      dev->netdev->dev_addr);
+	}
 }
 
 static int rtl8150_set_mac_address(struct net_device *netdev, void *p)
-- 
2.25.1