Return-Path: linux-nfs-owner@vger.kernel.org Received: from mailhub.sw.ru ([195.214.232.25]:37389 "EHLO relay.sw.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755713Ab3L3O0E (ORCPT ); Mon, 30 Dec 2013 09:26:04 -0500 Subject: [PATCH] nfsd: check passed socket's net matches NFSd superblock's one To: bfields@fieldses.org From: Stanislav Kinsbursky Cc: wengmeiling.weng@huawei.com, greg@kroah.com, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, devel@openvz.org Date: Mon, 30 Dec 2013 17:23:59 +0300 Message-ID: <20131230142339.16166.28243.stgit@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Sender: linux-nfs-owner@vger.kernel.org List-ID: There could be a case, when NFSd file system is mounted in network, different to socket's one, like below: "ip netns exec" creates new network and mount namespace, which duplicates NFSd mount point, created in init_net context. And thus NFS server stop in nested network context leads to RPCBIND client destruction in init_net. Then, on NFSd start in nested network context, rpc.nfsd process creates socket in nested net and passes it into "write_ports", which leads to RPCBIND sockets creation in init_net context because of the same reason (NFSd monut point was created in init_net context). An attempt to register passed socket in nested net leads to panic, because no RPCBIND client present in nexted network namespace. This patch add check that passed socket's net matches NFSd superblock's one. And returns -EINVAL error to user psace otherwise. Reported-by: Weng Meiling Signed-off-by: Stanislav Kinsbursky Cc: stable@vger.kernel.org --- fs/nfsd/nfsctl.c | 5 +++++ include/linux/sunrpc/svcsock.h | 1 + net/sunrpc/svcsock.c | 11 +++++++++++ 3 files changed, 17 insertions(+), 0 deletions(-) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 7f55517..f34d9de 100644 --- a/fs/nfsd/nfsctl.c +++ b/fs/nfsd/nfsctl.c @@ -699,6 +699,11 @@ static ssize_t __write_ports_addfd(char *buf, struct net *net) if (err != 0 || fd < 0) return -EINVAL; + if (svc_alien_sock(net, fd)) { + printk(KERN_ERR "%s: socket net is different to NFSd's one\n", __func__); + return -EINVAL; + } + err = nfsd_create_serv(net); if (err != 0) return err; diff --git a/include/linux/sunrpc/svcsock.h b/include/linux/sunrpc/svcsock.h index 62fd1b7..947009e 100644 --- a/include/linux/sunrpc/svcsock.h +++ b/include/linux/sunrpc/svcsock.h @@ -56,6 +56,7 @@ int svc_recv(struct svc_rqst *, long); int svc_send(struct svc_rqst *); void svc_drop(struct svc_rqst *); void svc_sock_update_bufs(struct svc_serv *serv); +bool svc_alien_sock(struct net *net, int fd); int svc_addsock(struct svc_serv *serv, const int fd, char *name_return, const size_t len); void svc_init_xprt_sock(void); diff --git a/net/sunrpc/svcsock.c b/net/sunrpc/svcsock.c index b6e59f0..3ba5b87 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1397,6 +1397,17 @@ static struct svc_sock *svc_setup_socket(struct svc_serv *serv, return svsk; } +bool svc_alien_sock(struct net *net, int fd) +{ + int err; + struct socket *sock = sockfd_lookup(fd, &err); + + if (sock && (sock_net(sock->sk) != net)) + return true; + return false; +} +EXPORT_SYMBOL_GPL(svc_alien_sock); + /** * svc_addsock - add a listener socket to an RPC service * @serv: pointer to RPC service to which to add a new listener