net: reject creation of netdev names with colons

[ Upstream commit a4176a93 ]

colons are used as a separator in netdev device lookup in dev_ioctl.c

Specific functions are SIOCGIFTXQLEN SIOCETHTOOL SIOCSIFNAME
Signed-off-by: Matthew Thode <mthode@mthode.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
(cherry picked from commit d501ebeb)
Signed-off-by: Willy Tarreau <w@1wt.eu>

net/core/dev.c

@@ -779,7 +779,7 @@ int dev_valid_name(const char *name)
 		return 0;
 
 	while (*name) {
-		if (*name == '/' || isspace(*name))
+		if (*name == '/' || *name == ':' || isspace(*name))
 			return 0;
 		name++;
 	}