From 344f3a6bce11dd3d483d7e36dce33b22427ff621 Mon Sep 17 00:00:00 2001 From: Stanislav Kinsbursky Date: Wed, 26 Feb 2014 16:50:01 +0300 Subject: [PATCH] nfsd: check passed socket's net matches NFSd superblock's one commit 3064639423c48d6e0eb9ecc27c512a58e38c6c57 upstream. 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. v2: Put socket on exit. Reported-by: Weng Meiling Signed-off-by: Stanislav Kinsbursky Signed-off-by: J. Bruce Fields Signed-off-by: Greg Kroah-Hartman --- fs/nfsd/nfsctl.c | 5 +++++ include/linux/sunrpc/svcsock.h | 1 + net/sunrpc/svcsock.c | 16 ++++++++++++++++ 3 files changed, 22 insertions(+) diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c index 7f555179bf81..f34d9de802ab 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 62fd1b756e99..947009ed5996 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 305374d4fb98..422759bae60d 100644 --- a/net/sunrpc/svcsock.c +++ b/net/sunrpc/svcsock.c @@ -1393,6 +1393,22 @@ 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); + bool ret = false; + + if (!sock) + goto out; + if (sock_net(sock->sk) != net) + ret = true; + sockfd_put(sock); +out: + return ret; +} +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 -- 2.34.1