From: Dan Carpenter Date: Fri, 23 Aug 2013 08:15:37 +0000 (+0300) Subject: ipip: potential race in ip_tunnel_init_net() X-Git-Url: https://git.karo-electronics.de/?a=commitdiff_plain;h=b4de77ade3fc56e41b978b68d78a351dab28b74e;p=linux-beck.git ipip: potential race in ip_tunnel_init_net() Eric Dumazet says that my previous fix for an ERR_PTR dereference (ea857f28ab 'ipip: dereferencing an ERR_PTR in ip_tunnel_init_net()') could be racy and suggests the following fix instead. Reported-by: Eric Dumazet Signed-off-by: Dan Carpenter Signed-off-by: David S. Miller --- diff --git a/net/ipv4/ip_tunnel.c b/net/ipv4/ip_tunnel.c index 24549b4aeae2..830de3f4e293 100644 --- a/net/ipv4/ip_tunnel.c +++ b/net/ipv4/ip_tunnel.c @@ -854,16 +854,14 @@ int ip_tunnel_init_net(struct net *net, int ip_tnl_net_id, rtnl_lock(); itn->fb_tunnel_dev = __ip_tunnel_create(net, ops, &parms); - rtnl_unlock(); - - if (IS_ERR(itn->fb_tunnel_dev)) - return PTR_ERR(itn->fb_tunnel_dev); /* FB netdevice is special: we have one, and only one per netns. * Allowing to move it to another netns is clearly unsafe. */ - itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; + if (!IS_ERR(itn->fb_tunnel_dev)) + itn->fb_tunnel_dev->features |= NETIF_F_NETNS_LOCAL; + rtnl_unlock(); - return 0; + return PTR_RET(itn->fb_tunnel_dev); } EXPORT_SYMBOL_GPL(ip_tunnel_init_net);