Return-Path: linux-nfs-owner@vger.kernel.org Received: from relay.parallels.com ([195.214.232.42]:59642 "EHLO relay.parallels.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751825AbaBSK0j (ORCPT ); Wed, 19 Feb 2014 05:26:39 -0500 Message-ID: <530486D9.7010502@parallels.com> Date: Wed, 19 Feb 2014 14:26:33 +0400 From: Stanislav Kinsbursky MIME-Version: 1.0 To: "J. Bruce Fields" CC: Weng Meiling , , , , Subject: Re: [PATCH] nfsd: check passed socket's net matches NFSd superblock's one 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> In-Reply-To: <20140218154406.GD4319@fieldses.org> Content-Type: text/plain; charset="UTF-8"; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: 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. > --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