[RTNETLINK]: Fix netdevice name corruption

When changing a device by ifindex without including a IFLA_IFNAME
attribute, the ifname variable contains random garbage and is used
to change the device name.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 2 insertions, 0 deletions

diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c
index 63b882ac288a..d8e25e08cb7e 100644
--- a/net/core/rtnetlink.c
+++ b/net/core/rtnetlink.c
@@ -394,6 +394,8 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg)
 
         if (tb[IFLA_IFNAME])
                 nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ);
+        else
+                ifname[0] = '\0';
 
         err = -EINVAL;
         ifm = nlmsg_data(nlh);