ipv4: fail early when creating netdev named all or default

We create a proc dir for each network device, this will cause
conflicts when the devices have name "all" or "default".

Rather than emitting an ugly kernel warning, we could just
fail earlier by checking the device name.

Reported-by: Stephane Chazelas <stephane.chazelas@gmail.com>
Cc: "David S. Miller" <davem@davemloft.net>
Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 6 insertions, 0 deletions

diff --git a/include/net/ip.h b/include/net/ip.h
index ca14799545fd..09b32da1b929 100644
--- a/include/net/ip.h
+++ b/include/net/ip.h
@@ -216,6 +216,12 @@ static inline int inet_is_local_reserved_port(struct net *net, int port)
                 return 0;
         return test_bit(port, net->ipv4.sysctl_local_reserved_ports);
 }
+
+static inline bool sysctl_dev_name_is_allowed(const char *name)
+{
+        return strcmp(name, "default") != 0  && strcmp(name, "all") != 0;
+}
+
 #else
 static inline int inet_is_local_reserved_port(struct net *net, int port)
 {