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authorStanislav Kinsbursky <skinsbursky@parallels.com>2014-02-26 16:50:01 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-05-06 07:59:28 -0700
commit34ef215eede8f77b8f27d35096aa9e4aa149d522 (patch)
tree498733b8a20d7d583c0394d09ef453d0ff287486
parentf7cffcfc0ffd809f1f6e0c679888cb378984716a (diff)
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 <wengmeiling.weng@huawei.com> Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
-rw-r--r--fs/nfsd/nfsctl.c5
-rw-r--r--include/linux/sunrpc/svcsock.h1
-rw-r--r--net/sunrpc/svcsock.c16
3 files changed, 22 insertions, 0 deletions
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 b6e59f0a9475..d06cb8752dcd 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1397,6 +1397,22 @@ 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