From: Sultan Alsawaf <sultanxda@gmail.com>
Date: Wed, 6 Jun 2018 22:56:54 +0000 (-0700)
Subject: ip_tunnel: Fix name string concatenate in __ip_tunnel_create()
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=000ade8016400d93b4d7c89970d96b8c14773d45;p=linux.git

ip_tunnel: Fix name string concatenate in __ip_tunnel_create()

By passing a limit of 2 bytes to strncat, strncat is limited to writing
fewer bytes than what it's supposed to append to the name here.

Since the bounds are checked on the line above this, just remove the string
bounds checks entirely since they're unneeded.

Signed-off-by: Sultan Alsawaf <sultanxda@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 38d906baf1df8..c4f5602308edc 100644
--- a/net/ipv4/ip_tunnel.c
+++ b/net/ipv4/ip_tunnel.c
@@ -261,8 +261,8 @@ static struct net_device *__ip_tunnel_create(struct net *net,
 	} else {
 		if (strlen(ops->kind) > (IFNAMSIZ - 3))
 			goto failed;
-		strlcpy(name, ops->kind, IFNAMSIZ);
-		strncat(name, "%d", 2);
+		strcpy(name, ops->kind);
+		strcat(name, "%d");
 	}
 
 	ASSERT_RTNL();