1 files changed, 70 insertions, 34 deletions

diff --git a/fs/nfs/idmap.c b/fs/nfs/idmap.c
index 27dde503a6b6..675b389cba5b 100644
--- a/fs/nfs/idmap.c
+++ b/fs/nfs/idmap.c
@@ -55,18 +55,19 @@
 static const struct cred *id_resolver_cache;
 static struct key_type key_type_id_resolver_legacy;
 
-struct idmap {
-	struct rpc_pipe		*idmap_pipe;
-	struct key_construction	*idmap_key_cons;
-	struct mutex		idmap_mutex;
-};
-
 struct idmap_legacy_upcalldata {
 	struct rpc_pipe_msg pipe_msg;
 	struct idmap_msg idmap_msg;
+	struct key_construction	*key_cons;
 	struct idmap *idmap;
 };
 
+struct idmap {
+	struct rpc_pipe		*idmap_pipe;
+	struct idmap_legacy_upcalldata *idmap_upcall_data;
+	struct mutex		idmap_mutex;
+};
+
 /**
  * nfs_fattr_init_names - initialise the nfs_fattr owner_name/group_name fields
  * @fattr: fully initialised struct nfs_fattr
@@ -330,7 +331,6 @@ static ssize_t nfs_idmap_get_key(const char *name, size_t namelen,
 		ret = nfs_idmap_request_key(&key_type_id_resolver_legacy,
 					    name, namelen, type, data,
 					    data_size, idmap);
-		idmap->idmap_key_cons = NULL;
 		mutex_unlock(&idmap->idmap_mutex);
 	}
 	return ret;
@@ -465,8 +465,6 @@ nfs_idmap_new(struct nfs_client *clp)
 	struct rpc_pipe *pipe;
 	int error;
 
-	BUG_ON(clp->cl_idmap != NULL);
-
 	idmap = kzalloc(sizeof(*idmap), GFP_KERNEL);
 	if (idmap == NULL)
 		return -ENOMEM;
@@ -510,7 +508,6 @@ static int __rpc_pipefs_event(struct nfs_client *clp, unsigned long event,
 
 	switch (event) {
 	case RPC_PIPEFS_MOUNT:
-		BUG_ON(clp->cl_rpcclient->cl_dentry == NULL);
 		err = __nfs_idmap_register(clp->cl_rpcclient->cl_dentry,
 						clp->cl_idmap,
 						clp->cl_idmap->idmap_pipe);
@@ -662,6 +659,35 @@ out:
 	return ret;
 }
 
+static bool
+nfs_idmap_prepare_pipe_upcall(struct idmap *idmap,
+		struct idmap_legacy_upcalldata *data)
+{
+	if (idmap->idmap_upcall_data != NULL) {
+		WARN_ON_ONCE(1);
+		return false;
+	}
+	idmap->idmap_upcall_data = data;
+	return true;
+}
+
+static void
+nfs_idmap_complete_pipe_upcall_locked(struct idmap *idmap, 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);
+}
+
+static void
+nfs_idmap_abort_pipe_upcall(struct idmap *idmap, int ret)
+{
+	if (idmap->idmap_upcall_data != NULL)
+		nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+}
+
 static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 				   const char *op,
 				   void *aux)
@@ -686,17 +712,15 @@ static int nfs_idmap_legacy_upcall(struct key_construction *cons,
 	if (ret < 0)
 		goto out2;
 
-	BUG_ON(idmap->idmap_key_cons != NULL);
-	idmap->idmap_key_cons = cons;
+	ret = -EAGAIN;
+	if (!nfs_idmap_prepare_pipe_upcall(idmap, data))
+		goto out2;
 
 	ret = rpc_queue_upcall(idmap->idmap_pipe, msg);
 	if (ret < 0)
-		goto out3;
+		nfs_idmap_abort_pipe_upcall(idmap, ret);
 
 	return ret;
-
-out3:
-	idmap->idmap_key_cons = NULL;
 out2:
 	kfree(data);
 out1:
@@ -711,21 +735,32 @@ static int nfs_idmap_instantiate(struct key *key, struct key *authkey, char *dat
 					authkey);
 }
 
-static int nfs_idmap_read_message(struct idmap_msg *im, struct key *key, struct key *authkey)
+static int nfs_idmap_read_and_verify_message(struct idmap_msg *im,
+		struct idmap_msg *upcall,
+		struct key *key, struct key *authkey)
 {
 	char id_str[NFS_UINT_MAXLEN];
-	int ret = -EINVAL;
+	int ret = -ENOKEY;
 
+	/* ret = -ENOKEY */
+	if (upcall->im_type != im->im_type || upcall->im_conv != im->im_conv)
+		goto out;
 	switch (im->im_conv) {
 	case IDMAP_CONV_NAMETOID:
+		if (strcmp(upcall->im_name, im->im_name) != 0)
+			break;
 		sprintf(id_str, "%d", im->im_id);
 		ret = nfs_idmap_instantiate(key, authkey, id_str);
 		break;
 	case IDMAP_CONV_IDTONAME:
+		if (upcall->im_id != im->im_id)
+			break;
 		ret = nfs_idmap_instantiate(key, authkey, im->im_name);
 		break;
+	default:
+		ret = -EINVAL;
 	}
-
+out:
 	return ret;
 }
 
@@ -737,14 +772,16 @@ idmap_pipe_downcall(struct file *filp, const char __user *src, size_t mlen)
 	struct key_construction *cons;
 	struct idmap_msg im;
 	size_t namelen_in;
-	int ret;
+	int ret = -ENOKEY;
 
 	/* If instantiation is successful, anyone waiting for key construction
 	 * 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.
 	 */
-	cons = ACCESS_ONCE(idmap->idmap_key_cons);
-	idmap->idmap_key_cons = NULL;
+	if (idmap->idmap_upcall_data == NULL)
+		goto out_noupcall;
+
+	cons = idmap->idmap_upcall_data->key_cons;
 
 	if (mlen != sizeof(im)) {
 		ret = -ENOSPC;
@@ -765,16 +802,19 @@ 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_message(&im, cons->key, cons->authkey);
+	ret = nfs_idmap_read_and_verify_message(&im,
+			&idmap->idmap_upcall_data->idmap_msg,
+			cons->key, cons->authkey);
 	if (ret >= 0) {
 		key_set_timeout(cons->key, nfs_idmap_cache_timeout);
 		ret = mlen;
 	}
 
 out:
-	complete_request_key(cons, ret);
+	nfs_idmap_complete_pipe_upcall_locked(idmap, ret);
+out_noupcall:
 	return ret;
 }
 
@@ -785,14 +825,9 @@ idmap_pipe_destroy_msg(struct rpc_pipe_msg *msg)
 			struct idmap_legacy_upcalldata,
 			pipe_msg);
 	struct idmap *idmap = data->idmap;
-	struct key_construction *cons;
-	if (msg->errno) {
-		cons = ACCESS_ONCE(idmap->idmap_key_cons);
-		idmap->idmap_key_cons = NULL;
-		complete_request_key(cons, msg->errno);
-	}
-	/* Free memory allocated in nfs_idmap_legacy_upcall() */
-	kfree(data);
+
+	if (msg->errno)
+		nfs_idmap_abort_pipe_upcall(idmap, msg->errno);
 }
 
 static void
@@ -800,7 +835,8 @@ idmap_release_pipe(struct inode *inode)
 {
 	struct rpc_inode *rpci = RPC_I(inode);
 	struct idmap *idmap = (struct idmap *)rpci->private;
-	idmap->idmap_key_cons = NULL;
+
+	nfs_idmap_abort_pipe_upcall(idmap, -EPIPE);
 }
 
 int nfs_map_name_to_uid(const struct nfs_server *server, const char *name, size_t namelen, __u32 *uid)