From 66b068604903849c5dee3842eb72564064c64c72 Mon Sep 17 00:00:00 2001 From: Andy Adamson Date: Thu, 12 Jun 2014 15:02:32 -0400 Subject: NFSv4: test SECINFO RPC_AUTH_GSS pseudoflavors for support Fix nfs4_negotiate_security to create an rpc_clnt used to test each SECINFO returned pseudoflavor. Check credential creation (and gss_context creation) which is important for RPC_AUTH_GSS pseudoflavors which can fail for multiple reasons including mis-configuration. Don't call nfs4_negotiate in nfs4_submount as it was just called by nfs4_proc_lookup_mountpoint (nfs4_proc_lookup_common) Signed-off-by: Andy Adamson [Trond: fix corrupt return value from nfs_find_best_sec()] Signed-off-by: Trond Myklebust --- fs/nfs/nfs4_fs.h | 2 +- fs/nfs/nfs4namespace.c | 98 ++++++++++++++++++++++++++++---------------------- fs/nfs/nfs4proc.c | 2 +- net/sunrpc/auth.c | 1 + 4 files changed, 58 insertions(+), 45 deletions(-) diff --git a/fs/nfs/nfs4_fs.h b/fs/nfs/nfs4_fs.h index f63cb87cd730..ba2affa51941 100644 --- a/fs/nfs/nfs4_fs.h +++ b/fs/nfs/nfs4_fs.h @@ -230,7 +230,7 @@ int nfs_atomic_open(struct inode *, struct dentry *, struct file *, extern struct file_system_type nfs4_fs_type; /* nfs4namespace.c */ -struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *, struct inode *, struct qstr *); +struct rpc_clnt *nfs4_negotiate_security(struct rpc_clnt *, struct inode *, struct qstr *); struct vfsmount *nfs4_submount(struct nfs_server *, struct dentry *, struct nfs_fh *, struct nfs_fattr *); int nfs4_replace_transport(struct nfs_server *server, diff --git a/fs/nfs/nfs4namespace.c b/fs/nfs/nfs4namespace.c index fd4dcb67cd15..3d83cb1fdc70 100644 --- a/fs/nfs/nfs4namespace.c +++ b/fs/nfs/nfs4namespace.c @@ -139,17 +139,22 @@ static size_t nfs_parse_server_name(char *string, size_t len, * @server: NFS server struct * @flavors: List of security tuples returned by SECINFO procedure * - * Return the pseudoflavor of the first security mechanism in - * "flavors" that is locally supported. The "flavors" array + * Return an rpc client that uses the first security mechanism in + * "flavors" that is locally supported. The "flavors" array * is searched in the order returned from the server, per RFC 3530 - * recommendation. + * recommendation and each flavor is checked for membership in the + * sec= mount option list if it exists. * * Return -EPERM if no matching flavor is found in the array. + * + * Please call rpc_shutdown_client() when you are done with this rpc client. + * */ -static rpc_authflavor_t nfs_find_best_sec(struct nfs_server *server, +static struct rpc_clnt *nfs_find_best_sec(struct rpc_clnt *clnt, + struct nfs_server *server, struct nfs4_secinfo_flavors *flavors) { - rpc_authflavor_t pseudoflavor; + rpc_authflavor_t pflavor; struct nfs4_secinfo4 *secinfo; unsigned int i; @@ -160,58 +165,73 @@ static rpc_authflavor_t nfs_find_best_sec(struct nfs_server *server, case RPC_AUTH_NULL: case RPC_AUTH_UNIX: case RPC_AUTH_GSS: - pseudoflavor = rpcauth_get_pseudoflavor(secinfo->flavor, + pflavor = rpcauth_get_pseudoflavor(secinfo->flavor, &secinfo->flavor_info); - /* make sure pseudoflavor matches sec= mount opt */ - if (pseudoflavor != RPC_AUTH_MAXFLAVOR && - nfs_auth_info_match(&server->auth_info, - pseudoflavor)) - return pseudoflavor; - break; + /* does the pseudoflavor match a sec= mount opt? */ + if (pflavor != RPC_AUTH_MAXFLAVOR && + nfs_auth_info_match(&server->auth_info, pflavor)) { + struct rpc_clnt *new; + struct rpc_cred *cred; + + /* Cloning creates an rpc_auth for the flavor */ + new = rpc_clone_client_set_auth(clnt, pflavor); + if (IS_ERR(new)) + continue; + /** + * Check that the user actually can use the + * flavor. This is mostly for RPC_AUTH_GSS + * where cr_init obtains a gss context + */ + cred = rpcauth_lookupcred(new->cl_auth, 0); + if (IS_ERR(cred)) { + rpc_shutdown_client(new); + continue; + } + put_rpccred(cred); + return new; + } } } - - return -EPERM; + return ERR_PTR(-EPERM); } -static rpc_authflavor_t nfs4_negotiate_security(struct inode *inode, struct qstr *name) +/** + * nfs4_negotiate_security - in response to an NFS4ERR_WRONGSEC on lookup, + * return an rpc_clnt that uses the best available security flavor with + * respect to the secinfo flavor list and the sec= mount options. + * + * @clnt: RPC client to clone + * @inode: directory inode + * @name: lookup name + * + * Please call rpc_shutdown_client() when you are done with this rpc client. + */ +struct rpc_clnt * +nfs4_negotiate_security(struct rpc_clnt *clnt, struct inode *inode, + struct qstr *name) { struct page *page; struct nfs4_secinfo_flavors *flavors; - rpc_authflavor_t flavor; + struct rpc_clnt *new; int err; page = alloc_page(GFP_KERNEL); if (!page) - return -ENOMEM; + return ERR_PTR(-ENOMEM); + flavors = page_address(page); err = nfs4_proc_secinfo(inode, name, flavors); if (err < 0) { - flavor = err; + new = ERR_PTR(err); goto out; } - flavor = nfs_find_best_sec(NFS_SERVER(inode), flavors); + new = nfs_find_best_sec(clnt, NFS_SERVER(inode), flavors); out: put_page(page); - return flavor; -} - -/* - * Please call rpc_shutdown_client() when you are done with this client. - */ -struct rpc_clnt *nfs4_create_sec_client(struct rpc_clnt *clnt, struct inode *inode, - struct qstr *name) -{ - rpc_authflavor_t flavor; - - flavor = nfs4_negotiate_security(inode, name); - if ((int)flavor < 0) - return ERR_PTR((int)flavor); - - return rpc_clone_client_set_auth(clnt, flavor); + return new; } static struct vfsmount *try_location(struct nfs_clone_mount *mountdata, @@ -394,14 +414,6 @@ struct vfsmount *nfs4_submount(struct nfs_server *server, struct dentry *dentry, if (client->cl_auth->au_flavor != flavor) flavor = client->cl_auth->au_flavor; - else { - rpc_authflavor_t new = nfs4_negotiate_security(dir, name); - if ((int)new < 0) { - mnt = ERR_PTR((int)new); - goto out; - } - flavor = new; - } mnt = nfs_do_submount(dentry, fh, fattr, flavor); out: rpc_shutdown_client(client); diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 285ad5334018..4bf3d97cc5a0 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -3247,7 +3247,7 @@ static int nfs4_proc_lookup_common(struct rpc_clnt **clnt, struct inode *dir, err = -EPERM; if (client != *clnt) goto out; - client = nfs4_create_sec_client(client, dir, name); + client = nfs4_negotiate_security(client, dir, name); if (IS_ERR(client)) return PTR_ERR(client); diff --git a/net/sunrpc/auth.c b/net/sunrpc/auth.c index 247e973544bf..f77366717420 100644 --- a/net/sunrpc/auth.c +++ b/net/sunrpc/auth.c @@ -592,6 +592,7 @@ rpcauth_lookupcred(struct rpc_auth *auth, int flags) put_group_info(acred.group_info); return ret; } +EXPORT_SYMBOL_GPL(rpcauth_lookupcred); void rpcauth_init_cred(struct rpc_cred *cred, const struct auth_cred *acred, -- cgit v1.2.3