1 files changed, 66 insertions, 60 deletions

diff --git a/fs/nfs/nfs4idmap.c b/fs/nfs/nfs4idmap.c
index 3f23b6840547..9e1c48c5c0b8 100644
--- a/fs/nfs/nfs4idmap.c
+++ b/fs/nfs/nfs4idmap.c
@@ -44,7 +44,9 @@
 #include <linux/keyctl.h>
 #include <linux/key-type.h>
 #include <keys/user-type.h>
+#include <keys/request_key_auth-type.h>
 #include <linux/module.h>
+#include <linux/user_namespace.h>
 
 #include "internal.h"
 #include "netns.h"
@@ -59,7 +61,7 @@ static struct key_type key_type_id_resolver_legacy;
 struct idmap_legacy_upcalldata {
 	struct rpc_pipe_msg pipe_msg;
 	struct idmap_msg idmap_msg;
-	struct key_construction	*key_cons;
+	struct key	*authkey;
 	struct idmap *idmap;
 };
 
@@ -68,8 +70,16 @@ struct idmap {
 	struct rpc_pipe		*idmap_pipe;
 	struct idmap_legacy_upcalldata *idmap_upcall_data;
 	struct mutex		idmap_mutex;
+	struct user_namespace	*user_ns;
 };
 
+static struct user_namespace *idmap_userns(const struct idmap *idmap)
+{
+	if (idmap && idmap->user_ns)
+		return idmap->user_ns;
+	return &init_user_ns;
+}
+
 /**
  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  * @fattr: fully initialised struct nfs_fattr
@@ -193,7 +203,7 @@ int nfs_idmap_init(void)
 	printk(KERN_NOTICE "NFS: Registering the %s key type\n",
 		key_type_id_resolver.name);
 
-	cred = prepare_kernel_cred(NULL);
+	cred = prepare_kernel_cred(&init_task);
 	if (!cred)
 		return -ENOMEM;
 
@@ -270,18 +280,19 @@ static struct key *nfs_idmap_request_key(const char *name, size_t namelen,
 					 const char *type, struct idmap *idmap)
 {
 	char *desc;
-	struct key *rkey;
+	struct key *rkey = ERR_PTR(-EAGAIN);
 	ssize_t ret;
 
 	ret = nfs_idmap_get_desc(name, namelen, type, strlen(type), &desc);
 	if (ret < 0)
 		return ERR_PTR(ret);
 
-	rkey = request_key(&key_type_id_resolver, desc, "");
+	if (!idmap->user_ns || idmap->user_ns == &init_user_ns)
+		rkey = request_key(&key_type_id_resolver, desc, "");
 	if (IS_ERR(rkey)) {
 		mutex_lock(&idmap->idmap_mutex);
 		rkey = request_key_with_auxdata(&key_type_id_resolver_legacy,
-						desc, "", 0, idmap);
+						desc, NULL, "", 0, idmap);
 		mutex_unlock(&idmap->idmap_mutex);
 	}
 	if (!IS_ERR(rkey))
@@ -295,15 +306,12 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 				 const char *type, void *data,
 				 size_t data_size, struct idmap *idmap)
 {
-	const struct cred *saved_cred;
 	struct key *rkey;
 	const struct user_key_payload *payload;
 	ssize_t ret;
 
-	saved_cred = override_creds(id_resolver_cache);
-	rkey = nfs_idmap_request_key(name, namelen, type, idmap);
-	revert_creds(saved_cred);
-
+	scoped_with_creds(id_resolver_cache)
+		rkey = nfs_idmap_request_key(name, namelen, type, idmap);
 	if (IS_ERR(rkey)) {
 		ret = PTR_ERR(rkey);
 		goto out;
@@ -384,7 +392,7 @@ static const match_table_t nfs_idmap_tokens = {
 	{ Opt_find_err, NULL }
 };
 
-static int nfs_idmap_legacy_upcall(struct key_construction *, const char *, void *);
+static int nfs_idmap_legacy_upcall(struct key *, void *);
 static ssize_t idmap_pipe_downcall(struct file *, const char __user *,
 				   size_t);
 static void idmap_release_pipe(struct inode *);
@@ -413,26 +421,16 @@ static void nfs_idmap_pipe_destroy(struct dentry *dir,
 		struct rpc_pipe_dir_object *pdo)
 {
 	struct idmap *idmap = pdo->pdo_data;
-	struct rpc_pipe *pipe = idmap->idmap_pipe;
 
-	if (pipe->dentry) {
-		rpc_unlink(pipe->dentry);
-		pipe->dentry = NULL;
-	}
+	rpc_unlink(idmap->idmap_pipe);
 }
 
 static int nfs_idmap_pipe_create(struct dentry *dir,
 		struct rpc_pipe_dir_object *pdo)
 {
 	struct idmap *idmap = pdo->pdo_data;
-	struct rpc_pipe *pipe = idmap->idmap_pipe;
-	struct dentry *dentry;
 
-	dentry = rpc_mkpipe_dentry(dir, "idmap", idmap, pipe);
-	if (IS_ERR(dentry))
-		return PTR_ERR(dentry);
-	pipe->dentry = dentry;
-	return 0;
+	return rpc_mkpipe_dentry(dir, "idmap", idmap, idmap->idmap_pipe);
 }
 
 static const struct rpc_pipe_dir_object_ops nfs_idmap_pipe_dir_object_ops = {
@@ -451,6 +449,9 @@ nfs_idmap_new(struct nfs_client *clp)
 	if (idmap == NULL)
 		return -ENOMEM;
 
+	mutex_init(&idmap->idmap_mutex);
+	idmap->user_ns = get_user_ns(clp->cl_rpcclient->cl_cred->user_ns);
+
 	rpc_init_pipe_dir_object(&idmap->idmap_pdo,
 			&nfs_idmap_pipe_dir_object_ops,
 			idmap);
@@ -461,7 +462,6 @@ nfs_idmap_new(struct nfs_client *clp)
 		goto err;
 	}
 	idmap->idmap_pipe = pipe;
-	mutex_init(&idmap->idmap_mutex);
 
 	error = rpc_add_pipe_dir_object(clp->cl_net,
 			&clp->cl_rpcclient->cl_pipedir_objects,
@@ -474,6 +474,7 @@ nfs_idmap_new(struct nfs_client *clp)
 err_destroy_pipe:
 	rpc_destroy_pipe_data(idmap->idmap_pipe);
 err:
+	put_user_ns(idmap->user_ns);
 	kfree(idmap);
 	return error;
 }
@@ -490,6 +491,7 @@ nfs_idmap_delete(struct nfs_client *clp)
 			&clp->cl_rpcclient->cl_pipedir_objects,
 			&idmap->idmap_pdo);
 	rpc_destroy_pipe_data(idmap->idmap_pipe);
+	put_user_ns(idmap->user_ns);
 	kfree(idmap);
 }
 
@@ -506,7 +508,7 @@ static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 	switch (token) {
 	case Opt_find_uid:
 		im->im_type = IDMAP_TYPE_USER;
-		/* Fall through */
+		fallthrough;
 	case Opt_find_gid:
 		im->im_conv = IDMAP_CONV_NAMETOID;
 		ret = match_strlcpy(im->im_name, &substr, IDMAP_NAMESZ);
@@ -514,7 +516,7 @@ static int nfs_idmap_prepare_message(char *desc, struct idmap *idmap,
 
 	case Opt_find_user:
 		im->im_type = IDMAP_TYPE_USER;
-		/* Fall through */
+		fallthrough;
 	case Opt_find_group:
 		im->im_conv = IDMAP_CONV_IDTONAME;
 		ret = match_int(&substr, &im->im_id);
@@ -546,32 +548,30 @@ nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
 	return true;
 }
 
-static void
-nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, int ret)
+static void nfs_idmap_complete_pipe_upcall(struct idmap_legacy_upcalldata *data,
+					   int ret)
 {
-	struct key_construction *cons = idmap->idmap_upcall_data->key_cons;
-
-	kfree(idmap->idmap_upcall_data);
-	idmap->idmap_upcall_data = NULL;
-	complete_request_key(cons, ret);
+	complete_request_key(data->authkey, ret);
+	key_put(data->authkey);
+	kfree(data);
 }
 
-static void
-nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
+static void nfs_idmap_abort_pipe_upcall(struct idmap *idmap,
+					struct idmap_legacy_upcalldata *data,
+					int ret)
 {
-	if (idmap->idmap_upcall_data != NULL)
-		nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+	if (cmpxchg(&idmap->idmap_upcall_data, data, NULL) == data)
+		nfs_idmap_complete_pipe_upcall(data, ret);
 }
 
-static int nfs_idmap_legacy_upcall(struct key_construction *cons,
-				   const char *op,
-				   void *aux)
+static int nfs_idmap_legacy_upcall(struct key *authkey, void *aux)
 {
 	struct idmap_legacy_upcalldata *data;
+	struct request_key_auth *rka = get_request_key_auth(authkey);
 	struct rpc_pipe_msg *msg;
 	struct idmap_msg *im;
-	struct idmap *idmap = (struct idmap *)aux;
-	struct key *key = cons->key;
+	struct idmap *idmap = aux;
+	struct key *key = rka->target_key;
 	int ret = -ENOKEY;
 
 	if (!aux)
@@ -586,7 +586,7 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 	msg = &data->pipe_msg;
 	im = &data->idmap_msg;
 	data->idmap = idmap;
-	data->key_cons = cons;
+	data->authkey = key_get(authkey);
 
 	ret = nfs_idmap_prepare_message(key->description, idmap, im, msg);
 	if (ret < 0)
@@ -598,13 +598,13 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 
 	ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 	if (ret < 0)
-		nfs_idmap_abort_pipe_upcall(idmap, ret);
+		nfs_idmap_abort_pipe_upcall(idmap, data, ret);
 
 	return ret;
 out2:
 	kfree(data);
 out1:
-	complete_request_key(cons, ret);
+	complete_request_key(authkey, ret);
 	return ret;
 }
 
@@ -651,9 +651,11 @@ out:
 static ssize_t
 idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 {
+	struct request_key_auth *rka;
 	struct rpc_inode *rpci = RPC_I(file_inode(filp));
 	struct idmap *idmap = (struct idmap *)rpci->private;
-	struct key_construction *cons;
+	struct idmap_legacy_upcalldata *data;
+	struct key *authkey;
 	struct idmap_msg im;
 	size_t namelen_in;
 	int ret = -ENOKEY;
@@ -662,10 +664,12 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	 * will have been woken up and someone else may now have used
 	 * idmap_key_cons - so after this point we may no longer touch it.
 	 */
-	if (idmap->idmap_upcall_data == NULL)
+	data = xchg(&idmap->idmap_upcall_data, NULL);
+	if (data == NULL)
 		goto out_noupcall;
 
-	cons = idmap->idmap_upcall_data->key_cons;
+	authkey = data->authkey;
+	rka = get_request_key_auth(authkey);
 
 	if (mlen != sizeof(im)) {
 		ret = -ENOSPC;
@@ -686,18 +690,17 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	if (namelen_in == 0 || namelen_in == IDMAP_NAMESZ) {
 		ret = -EINVAL;
 		goto out;
-}
+	}
 
-	ret = nfs_idmap_read_and_verify_message(&im,
-			&idmap->idmap_upcall_data->idmap_msg,
-			cons->key, cons->authkey);
+	ret = nfs_idmap_read_and_verify_message(&im, &data->idmap_msg,
+						rka->target_key, authkey);
 	if (ret >= 0) {
-		key_set_timeout(cons->key, nfs_idmap_cache_timeout);
+		key_set_timeout(rka->target_key, nfs_idmap_cache_timeout);
 		ret = mlen;
 	}
 
 out:
-	nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+	nfs_idmap_complete_pipe_upcall(data, ret);
 out_noupcall:
 	return ret;
 }
@@ -711,7 +714,7 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 	struct idmap *idmap = data->idmap;
 
 	if (msg->errno)
-		nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
+		nfs_idmap_abort_pipe_upcall(idmap, data, msg->errno);
 }
 
 static void
@@ -719,8 +722,11 @@ idmap_release_pipe(struct inode *inode)
 {
 	struct rpc_inode *rpci = RPC_I(inode);
 	struct idmap *idmap = (struct idmap *)rpci->private;
+	struct idmap_legacy_upcalldata *data;
 
-	nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
+	data = xchg(&idmap->idmap_upcall_data, NULL);
+	if (data)
+		nfs_idmap_complete_pipe_upcall(data, -EPIPE);
 }
 
 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, kuid_t *uid)
@@ -732,7 +738,7 @@ int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_
 	if (!nfs_map_string_to_numeric(name, namelen, &id))
 		ret = nfs_idmap_lookup_id(name, namelen, "uid", &id, idmap);
 	if (ret == 0) {
-		*uid = make_kuid(&init_user_ns, id);
+		*uid = make_kuid(idmap_userns(idmap), id);
 		if (!uid_valid(*uid))
 			ret = -ERANGE;
 	}
@@ -749,7 +755,7 @@ int nfs_map_group_to_gid(const struct nfs_server *server, const char *name, size
 	if (!nfs_map_string_to_numeric(name, namelen, &id))
 		ret = nfs_idmap_lookup_id(name, namelen, "gid", &id, idmap);
 	if (ret == 0) {
-		*gid = make_kgid(&init_user_ns, id);
+		*gid = make_kgid(idmap_userns(idmap), id);
 		if (!gid_valid(*gid))
 			ret = -ERANGE;
 	}
@@ -763,7 +769,7 @@ int nfs_map_uid_to_name(const struct nfs_server *server, kuid_t uid, char *buf,
 	int ret = -EINVAL;
 	__u32 id;
 
-	id = from_kuid(&init_user_ns, uid);
+	id = from_kuid_munged(idmap_userns(idmap), uid);
 	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 		ret = nfs_idmap_lookup_name(id, "user", buf, buflen, idmap);
 	if (ret < 0)
@@ -777,7 +783,7 @@ int nfs_map_gid_to_group(const struct nfs_server *server, kgid_t gid, char *buf,
 	int ret = -EINVAL;
 	__u32 id;
 
-	id = from_kgid(&init_user_ns, gid);
+	id = from_kgid_munged(idmap_userns(idmap), gid);
 	if (!(server->caps & NFS_CAP_UIDGID_NOMAP))
 		ret = nfs_idmap_lookup_name(id, "group", buf, buflen, idmap);
 	if (ret < 0)