netdev - [PATCH] ip_tunnel: Fix GCC 8 warning in __ip_tunnel

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Message-Id: <20180607002715.25079-1-sultanxda@gmail.com>
Date:   Wed,  6 Jun 2018 17:27:15 -0700
From:   Sultan Alsawaf <sultanxda@...il.com>
To:     sultanxda@...il.com
Cc:     netdev@...r.kernel.org, davem@...emloft.net, kuznet@....inr.ac.ru,
        yoshfuji@...ux-ipv6.org
Subject: [PATCH] ip_tunnel: Fix GCC 8 warning in __ip_tunnel_create()

By passing a limit of 2 bytes to strncat, GCC 8 thinks that strncat is
limited to writing fewer bytes than what it's supposed to append to the
name here. However, strncat appends n+1 bytes to the destination, so this
is correct even though it doesn't look right.

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

Signed-off-by: Sultan Alsawaf <sultanxda@...il.com>
---
 net/ipv4/ip_tunnel.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c
index 38d906baf1df..c4f5602308ed 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();
-- 
2.17.1