Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753116AbbG3NvM (ORCPT ); Thu, 30 Jul 2015 09:51:12 -0400 Received: from userp1040.oracle.com ([156.151.31.81]:31470 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751010AbbG3NvI (ORCPT ); Thu, 30 Jul 2015 09:51:08 -0400 Date: Thu, 30 Jul 2015 15:50:36 +0200 From: Sowmini Varadhan To: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Cc: davem@davemloft.net, edumazet@google.com, willemb@google.com, ebiederm@xmission.com, alexander.h.duyck@intel.com, ast@plumgrid.com, hannes@stressinduktion.org, dborkman@redhat.com, sowmini.varadhan@oracle.com Subject: [PATCH v2 net] net: sk_clone_lock() should only do get_net() if the parent is not a kernel socket Message-ID: <20150730135036.GA17366@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.5.21 (2010-09-15) X-Source-IP: userv0022.oracle.com [156.151.31.74] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1676 Lines: 47 The newsk returned by sk_clone_lock should hold a get_net() reference if, and only if, the parent is not a kernel socket (making this similar to sk_alloc()). E.g,. for the SYN_RECV path, tcp_v4_syn_recv_sock->..inet_csk_clone_lock sets up the syn_recv newsk from sk_clone_lock. When the parent (listen) socket is a kernel socket (defined in sk_alloc() as having sk_net_refcnt == 0), then the newsk should also have a 0 sk_net_refcnt and should not hold a get_net() reference. Fixes: 26abe14379f8 ("net: Modify sk_alloc to not reference count the netns of kernel sockets.") Acked-by: Eric Dumazet Cc: Eric W. Biederman Signed-off-by: Sowmini Varadhan --- v2: pulled patch #3 out of the RFC patch-set for RDS-TCP netns fixes; Added Fixes, Acked-by, Cc fields based on mailing list feedback from Eric Dumazet. net/core/sock.c | 3 ++- 1 files changed, 2 insertions(+), 1 deletions(-) diff --git a/net/core/sock.c b/net/core/sock.c index 08f16db..371d1b7 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -1497,7 +1497,8 @@ struct sock *sk_clone_lock(const struct sock *sk, const gfp_t priority) sock_copy(newsk, sk); /* SANITY */ - get_net(sock_net(newsk)); + if (likely(newsk->sk_net_refcnt)) + get_net(sock_net(newsk)); sk_node_init(&newsk->sk_node); sock_lock_init(newsk); bh_lock_sock(newsk); -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/