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authorStanislav Kinsbursky <skinsbursky@parallels.com>2014-02-26 16:50:01 +0300
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2014-06-11 12:04:19 -0700
commita6d5f5393d055ba302edf4c59e6bfcee8b8892db (patch)
tree63e43cfdf60cbcc059a63783892036815e6a861e
parent6c14fee44389ab182ceab1df8fecbf2ffeb3a641 (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> Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com> [wengmeiling: backport to 3.4: adjust context] Signed-off-by: Weng Meiling <wengmeiling.weng@huawei.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 cebc9efed525..4db777d3dc05 100644
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -660,6 +660,11 @@ 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 cb4ac69e1f33..e4c6cec9ff1a 100644
--- a/include/linux/sunrpc/svcsock.h
+++ b/include/linux/sunrpc/svcsock.h
@@ -42,6 +42,7 @@ void svc_sock_update_bufs(struct svc_serv *serv);
int svc_sock_names(struct svc_serv *serv, char *buf,
const size_t buflen,
const char *toclose);
+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 f190ea96f112..4c23cfc0296c 100644
--- a/net/sunrpc/svcsock.c
+++ b/net/sunrpc/svcsock.c
@@ -1441,6 +1441,22 @@ 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