Commit 09bde6fd authored by Miguel García's avatar Miguel García Committed by Jakub Kicinski
Browse files

ipv6: ip6_gre: replace strcpy with strscpy for tunnel name 



Replace the strcpy() call that copies the device name into
tunnel->parms.name with strscpy(), to avoid potential overflow
and guarantee NULL termination. This uses the two-argument
form of strscpy(), where the destination size is inferred
from the array type.

Destination is tunnel->parms.name (size IFNAMSIZ).

Tested in QEMU (Alpine rootfs):
 - Created IPv6 GRE tunnels over loopback
 - Assigned overlay IPv6 addresses
 - Verified bidirectional ping through the tunnel
 - Changed tunnel parameters at runtime (`ip -6 tunnel change`)

Signed-off-by: default avatarMiguel García <miguelgarciaroman8@gmail.com>
Link: https://patch.msgid.link/20250818220203.899338-1-miguelgarciaroman8@gmail.com


Signed-off-by: default avatarJakub Kicinski <kuba@kernel.org>
parent 9efd5152

net/ipv6/ip6_gre.c

+5 −5
Original line number Diff line number Diff line
@@ -329,9 +329,9 @@ static struct ip6_tnl *ip6gre_tunnel_locate(struct net *net, 
	if (parms->name[0]) {

		if (!dev_valid_name(parms->name))

			return NULL;

		strscpy(name, parms->name, IFNAMSIZ);

		strscpy(name, parms->name);

	} else {

		strcpy(name, "ip6gre%d");

		strscpy(name, "ip6gre%d");

	}

	dev = alloc_netdev(sizeof(*t), name, NET_NAME_UNKNOWN,

			   ip6gre_tunnel_setup);
@@ -1469,7 +1469,7 @@ static int ip6gre_tunnel_init_common(struct net_device *dev) 
	tunnel = netdev_priv(dev);



	tunnel->dev = dev;

	strcpy(tunnel->parms.name, dev->name);

	strscpy(tunnel->parms.name, dev->name);



	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);

	if (ret)
@@ -1529,7 +1529,7 @@ static void ip6gre_fb_tunnel_init(struct net_device *dev) 


	tunnel->dev = dev;

	tunnel->net = dev_net(dev);

	strcpy(tunnel->parms.name, dev->name);

	strscpy(tunnel->parms.name, dev->name);



	tunnel->hlen		= sizeof(struct ipv6hdr) + 4;

}
@@ -1842,7 +1842,7 @@ static int ip6erspan_tap_init(struct net_device *dev) 
	tunnel = netdev_priv(dev);



	tunnel->dev = dev;

	strcpy(tunnel->parms.name, dev->name);

	strscpy(tunnel->parms.name, dev->name);



	ret = dst_cache_init(&tunnel->dst_cache, GFP_KERNEL);

	if (ret)