Netdev List

* [Patch net 3/3] team: use a larger struct for mac address
From: Cong Wang @ 2017-04-26  5:03 UTC (permalink / raw)
  To: netdev; +Cc: andreyknvl, Cong Wang, Jiri Pirko
In-Reply-To: <1493183003-884-1-git-send-email-xiyou.wangcong@gmail.com>

IPv6 tunnels use sizeof(struct in6_addr) as dev->addr_len,
but in many places especially bonding, we use struct sockaddr
to copy and set mac addr, this could lead to stack out-of-bounds
access.

Fix it by using a larger address storage.

Reported-by: Andrey Konovalov <andreyknvl@google.com>
Cc: Jiri Pirko <jiri@resnulli.us>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
---
 drivers/net/team/team.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

diff --git a/drivers/net/team/team.c b/drivers/net/team/team.c
index 85c0124..88878f1 100644
--- a/drivers/net/team/team.c
+++ b/drivers/net/team/team.c
@@ -60,10 +60,13 @@ static struct team_port *team_port_get_rtnl(const struct net_device *dev)
 static int __set_port_dev_addr(struct net_device *port_dev,
 			       const unsigned char *dev_addr)
 {
-	struct sockaddr addr;
+	struct {
+		unsigned short type;
+		unsigned char addr[MAX_ADDR_LEN];
+	} addr;
 
-	memcpy(addr.sa_data, dev_addr, port_dev->addr_len);
-	addr.sa_family = port_dev->type;
+	memcpy(addr.addr, dev_addr, port_dev->addr_len);
+	addr.type = port_dev->type;
 	return dev_set_mac_address(port_dev, &addr);
 }
 
-- 
2.5.5

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