Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:36991 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752132AbaBSOvB (ORCPT ); Wed, 19 Feb 2014 09:51:01 -0500 Date: Wed, 19 Feb 2014 09:50:43 -0500 From: "J. Bruce Fields" To: Stanislav Kinsbursky Cc: Weng Meiling , greg@kroah.com, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org, devel@openvz.org Subject: Re: [PATCH] nfsd: check passed socket's net matches NFSd superblock's one Message-ID: <20140219145043.GC8401@fieldses.org> References: <20131230142339.16166.28243.stgit@localhost.localdomain> <20140103222226.GD5164@fieldses.org> <52FEC818.7030604@huawei.com> <20140217221900.GA8401@fieldses.org> <53037A03.4020603@parallels.com> <20140218154406.GD4319@fieldses.org> <530486D9.7010502@parallels.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 In-Reply-To: <530486D9.7010502@parallels.com> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Wed, Feb 19, 2014 at 02:26:33PM +0400, Stanislav Kinsbursky wrote: > 18.02.2014 19:44, J. Bruce Fields пишет: > >On Tue, Feb 18, 2014 at 07:19:31PM +0400, Stanislav Kinsbursky wrote: > >>18.02.2014 02:19, J. Bruce Fields пишет: > >>>On Sat, Feb 15, 2014 at 09:51:20AM +0800, Weng Meiling wrote: > >>>>Hi Bruce, > >>>> > >>>>The upstream has merged your git tree for-3.14, but there is no this patch? > >>>>Do you forget this patch? > >>> > >>>Apologies, I'm not sure what happened. > >>> > >>>Looking back at it.... The patch causes all my pynfs reboot recovery > >>>tests to fail. They're just doing a "systemctl restart > >>>nfs-server.service", and "systemctl status nfs-server.service" shows in > >>>part > >>> > >>> ExecStart=/usr/sbin/rpc.nfsd $RPCNFSDARGS $RPCNFSDCOUNT (code=exited, status=1/FAILURE) > >>> > >>>So the patch is causing rpc.nfsd to fail? No network namespaces should > >>>be involved. > >>> > >>>I haven't investigated any further. > >>> > >> > >>Hi Bruce, > >>Are you sure, that exactly this patch broke your pynfs tests? > >>BTW, systemd manipulates namespaces. Maybe the patch revealed some pynfs internal bugs? > >>What do you think? > > > >It's really just "systemctl restart nfs-server.service" that the patch > >breaks, pynfs isn't involved much. > > > >The patch I'm actually using follows, but I believe the only difference > >is in the printk message? > > > > Yep, looks true. > That's strange: "systemctl restart nfs-server.service" works for me on Fedora 18 with kernel, based on your repo. OK, I'll take a closer look and let you know what I find. --b. > > >--b > > > >commit e1f2922c12cb59baba0f2c7726bee992a0861310 > >Author: Stanislav Kinsbursky > >Date: Mon Dec 30 17:23:59 2013 +0300 > > > > nfsd: check passed socket's net matches the NFSd superblock's > > > > The file descriptor written to the nfsd/portlist file could be for a > > socket in a different network namespace from the network namespace that > > the nfsd filesystem was mounted in, and this can cause a crash. > > > > For example: "ip netns exec" creates a new network and mount namespace, > > which duplicates the nfsd mount point which was created in the init_net > > context. Thus NFS server stop in the nested network context leads to > > RPCBIND client destruction in init_net. Then, on nfsd start in the > > nested network context, the rpc.nfsd process creates a socket in the > > nested net and passes it into "write_ports", which leads to RPCBIND > > socket creation in init_net context for the same reason (the nfsd mount > > point was created in the init_net context). An attempt to register > > passed socket in nested net leads to panic, because no RPCBIND client is > > present in the nested network namespace. > > > > This patch adds a check that the passed the socket's net matches the > > nfsd superblock's net, and returns -EINVAL error to user space if not. > > > > Reported-by: Weng Meiling > > Signed-off-by: Stanislav Kinsbursky > > Cc: stable@vger.kernel.org > > Signed-off-by: J. Bruce Fields > > > >diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c > >index 7f55517..1331766 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 from NFSd's\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 > > > > > -- > Best regards, > Stanislav Kinsbursky