diff --git a/fs/fuse/cuse.c b/fs/fuse/cuse.c
index eae2c11268bc..a10aca57bfe4 100644
--- a/fs/fuse/cuse.c
+++ b/fs/fuse/cuse.c
@@ -48,6 +48,7 @@
 #include <linux/stat.h>
 #include <linux/module.h>
 #include <linux/uio.h>
+#include <linux/user_namespace.h>
 
 #include "fuse_i.h"
 
@@ -498,7 +499,7 @@ static int cuse_channel_open(struct inode *inode, struct file *file)
 	if (!cc)
 		return -ENOMEM;
 
-	fuse_conn_init(&cc->fc);
+	fuse_conn_init(&cc->fc, current_user_ns());
 
 	fud = fuse_dev_alloc(&cc->fc);
 	if (!fud) {
diff --git a/fs/fuse/dev.c b/fs/fuse/dev.c
index a4f6f30d6d86..11b4cb0a0e2f 100644
--- a/fs/fuse/dev.c
+++ b/fs/fuse/dev.c
@@ -127,8 +127,8 @@ static void __fuse_put_request(struct fuse_req *req)
 
 static void fuse_req_init_context(struct fuse_conn *fc, struct fuse_req *req)
 {
-	req->in.h.uid = from_kuid_munged(&init_user_ns, current_fsuid());
-	req->in.h.gid = from_kgid_munged(&init_user_ns, current_fsgid());
+	req->in.h.uid = from_kuid(fc->user_ns, current_fsuid());
+	req->in.h.gid = from_kgid(fc->user_ns, current_fsgid());
 	req->in.h.pid = pid_nr_ns(task_pid(current), fc->pid_ns);
 }
 
@@ -186,7 +186,8 @@ static struct fuse_req *__fuse_get_req(struct fuse_conn *fc, unsigned npages,
 	__set_bit(FR_WAITING, &req->flags);
 	if (for_background)
 		__set_bit(FR_BACKGROUND, &req->flags);
-	if (req->in.h.pid == 0) {
+	if (req->in.h.pid == 0 || req->in.h.uid == (uid_t)-1 ||
+	    req->in.h.gid == (gid_t)-1) {
 		fuse_put_request(fc, req);
 		return ERR_PTR(-EOVERFLOW);
 	}
@@ -1248,7 +1249,8 @@ static ssize_t fuse_dev_do_read(struct fuse_dev *fud, struct file *file,
 	struct fuse_in *in;
 	unsigned reqsize;
 
-	if (task_active_pid_ns(current) != fc->pid_ns)
+	if (task_active_pid_ns(current) != fc->pid_ns ||
+	    current_user_ns() != fc->user_ns)
 		return -EIO;
 
  restart:
@@ -1880,7 +1882,8 @@ static ssize_t fuse_dev_do_write(struct fuse_dev *fud,
 	struct fuse_req *req;
 	struct fuse_out_header oh;
 
-	if (task_active_pid_ns(current) != fc->pid_ns)
+	if (task_active_pid_ns(current) != fc->pid_ns ||
+	    current_user_ns() != fc->user_ns)
 		return -EIO;
 
 	if (nbytes < sizeof(struct fuse_out_header))
diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c
index 5e2e08712d3b..f67f4dd86b36 100644
--- a/fs/fuse/dir.c
+++ b/fs/fuse/dir.c
@@ -243,9 +243,12 @@ static int fuse_dentry_revalidate(struct dentry *entry, unsigned int flags)
 		if (ret || (outarg.attr.mode ^ inode->i_mode) & S_IFMT)
 			goto invalid;
 
-		fuse_change_attributes(inode, &outarg.attr,
-				       entry_attr_timeout(&outarg),
-				       attr_version);
+		ret = fuse_change_attributes(inode, &outarg.attr,
+					     entry_attr_timeout(&outarg),
+					     attr_version);
+		if (ret)
+			goto invalid;
+
 		fuse_change_entry_timeout(entry, &outarg);
 	} else if (inode) {
 		fi = get_fuse_inode(inode);
@@ -319,8 +322,9 @@ int fuse_lookup_name(struct super_block *sb, u64 nodeid, struct qstr *name,
 	*inode = fuse_iget(sb, outarg->nodeid, outarg->generation,
 			   &outarg->attr, entry_attr_timeout(outarg),
 			   attr_version);
-	err = -ENOMEM;
-	if (!*inode) {
+	if (IS_ERR(*inode)) {
+		err = PTR_ERR(*inode);
+		*inode = NULL;
 		fuse_queue_forget(fc, forget, outarg->nodeid, 1);
 		goto out;
 	}
@@ -441,11 +445,11 @@ static int fuse_create_open(struct inode *dir, struct dentry *entry,
 	ff->open_flags = outopen.open_flags;
 	inode = fuse_iget(dir->i_sb, outentry.nodeid, outentry.generation,
 			  &outentry.attr, entry_attr_timeout(&outentry), 0);
-	if (!inode) {
+	if (IS_ERR(inode)) {
 		flags &= ~(O_CREAT | O_EXCL | O_TRUNC);
 		fuse_sync_release(ff, flags);
 		fuse_queue_forget(fc, forget, outentry.nodeid, 1);
-		err = -ENOMEM;
+		err = PTR_ERR(inode);
 		goto out_err;
 	}
 	kfree(forget);
@@ -547,9 +551,9 @@ static int create_new_entry(struct fuse_conn *fc, struct fuse_args *args,
 
 	inode = fuse_iget(dir->i_sb, outarg.nodeid, outarg.generation,
 			  &outarg.attr, entry_attr_timeout(&outarg), 0);
-	if (!inode) {
+	if (IS_ERR(inode)) {
 		fuse_queue_forget(fc, forget, outarg.nodeid, 1);
-		return -ENOMEM;
+		return PTR_ERR(inode);
 	}
 	kfree(forget);
 
@@ -841,8 +845,8 @@ static void fuse_fillattr(struct inode *inode, struct fuse_attr *attr,
 	stat->ino = attr->ino;
 	stat->mode = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 	stat->nlink = attr->nlink;
-	stat->uid = make_kuid(&init_user_ns, attr->uid);
-	stat->gid = make_kgid(&init_user_ns, attr->gid);
+	stat->uid = inode->i_uid;
+	stat->gid = inode->i_gid;
 	stat->rdev = inode->i_rdev;
 	stat->atime.tv_sec = attr->atime;
 	stat->atime.tv_nsec = attr->atimensec;
@@ -896,10 +900,10 @@ static int fuse_do_getattr(struct inode *inode, struct kstat *stat,
 			make_bad_inode(inode);
 			err = -EIO;
 		} else {
-			fuse_change_attributes(inode, &outarg.attr,
-					       attr_timeout(&outarg),
-					       attr_version);
-			if (stat)
+			err = fuse_change_attributes(inode, &outarg.attr,
+						     attr_timeout(&outarg),
+						     attr_version);
+			if (!err && stat)
 				fuse_fillattr(inode, &outarg.attr, stat);
 		}
 	}
@@ -1221,9 +1225,11 @@ static int fuse_direntplus_link(struct file *file,
 			fi->nlookup++;
 			spin_unlock(&fc->lock);
 
-			fuse_change_attributes(inode, &o->attr,
-					       entry_attr_timeout(o),
-					       attr_version);
+			err = fuse_change_attributes(inode, &o->attr,
+						     entry_attr_timeout(o),
+						     attr_version);
+			if (err)
+				goto out;
 
 			/*
 			 * The other branch to 'found' comes via fuse_iget()
@@ -1241,8 +1247,10 @@ static int fuse_direntplus_link(struct file *file,
 
 	inode = fuse_iget(dir->i_sb, o->nodeid, o->generation,
 			  &o->attr, entry_attr_timeout(o), attr_version);
-	if (!inode)
+	if (IS_ERR(inode)) {
+		err = PTR_ERR(inode);
 		goto out;
+	}
 
 	alias = d_splice_alias(inode, dentry);
 	err = PTR_ERR(alias);
@@ -1455,17 +1463,25 @@ static bool update_mtime(unsigned ivalid, bool trust_local_mtime)
 	return true;
 }
 
-static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg,
-			   bool trust_local_cmtime)
+static int iattr_to_fattr(struct fuse_conn *fc, struct iattr *iattr,
+			   struct fuse_setattr_in *arg, bool trust_local_cmtime)
 {
 	unsigned ivalid = iattr->ia_valid;
 
 	if (ivalid & ATTR_MODE)
 		arg->valid |= FATTR_MODE,   arg->mode = iattr->ia_mode;
-	if (ivalid & ATTR_UID)
-		arg->valid |= FATTR_UID,    arg->uid = from_kuid(&init_user_ns, iattr->ia_uid);
-	if (ivalid & ATTR_GID)
-		arg->valid |= FATTR_GID,    arg->gid = from_kgid(&init_user_ns, iattr->ia_gid);
+	if (ivalid & ATTR_UID) {
+		arg->uid = from_kuid(fc->user_ns, iattr->ia_uid);
+		if (arg->uid == (uid_t)-1)
+			return -EINVAL;
+		arg->valid |= FATTR_UID;
+	}
+	if (ivalid & ATTR_GID) {
+		arg->gid = from_kgid(fc->user_ns, iattr->ia_gid);
+		if (arg->gid == (gid_t)-1)
+			return -EINVAL;
+		arg->valid |= FATTR_GID;
+	}
 	if (ivalid & ATTR_SIZE)
 		arg->valid |= FATTR_SIZE,   arg->size = iattr->ia_size;
 	if (ivalid & ATTR_ATIME) {
@@ -1487,6 +1503,8 @@ static void iattr_to_fattr(struct iattr *iattr, struct fuse_setattr_in *arg,
 		arg->ctime = iattr->ia_ctime.tv_sec;
 		arg->ctimensec = iattr->ia_ctime.tv_nsec;
 	}
+
+	return 0;
 }
 
 /*
@@ -1625,7 +1643,9 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 
 	memset(&inarg, 0, sizeof(inarg));
 	memset(&outarg, 0, sizeof(outarg));
-	iattr_to_fattr(attr, &inarg, trust_local_cmtime);
+	err = iattr_to_fattr(fc, attr, &inarg, trust_local_cmtime);
+	if (err)
+		goto error;
 	if (file) {
 		struct fuse_file *ff = file->private_data;
 		inarg.valid |= FATTR_FH;
@@ -1660,8 +1680,13 @@ int fuse_do_setattr(struct inode *inode, struct iattr *attr,
 		/* FIXME: clear I_DIRTY_SYNC? */
 	}
 
-	fuse_change_attributes_common(inode, &outarg.attr,
-				      attr_timeout(&outarg));
+	err = fuse_change_attributes_common(inode, &outarg.attr,
+				            attr_timeout(&outarg));
+	if (err) {
+		spin_unlock(&fc->lock);
+		goto error;
+	}
+
 	oldsize = inode->i_size;
 	/* see the comment in fuse_change_attributes() */
 	if (!is_wb || is_truncate || !S_ISREG(inode->i_mode))
diff --git a/fs/fuse/fuse_i.h b/fs/fuse/fuse_i.h
index 143b595197b6..98c669ccfe7f 100644
--- a/fs/fuse/fuse_i.h
+++ b/fs/fuse/fuse_i.h
@@ -23,6 +23,7 @@
 #include <linux/poll.h>
 #include <linux/workqueue.h>
 #include <linux/pid_namespace.h>
+#include <linux/user_namespace.h>
 
 /** Max number of pages that can be used in a single read request */
 #define FUSE_MAX_PAGES_PER_REQ 32
@@ -460,6 +461,9 @@ struct fuse_conn {
 	/** The pid namespace for this mount */
 	struct pid_namespace *pid_ns;
 
+	/** The user namespace for this mount */
+	struct user_namespace *user_ns;
+
 	/** The fuse mount flags for this mount */
 	unsigned flags;
 
@@ -761,11 +765,11 @@ void fuse_init_symlink(struct inode *inode);
 /**
  * Change attributes of an inode
  */
-void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
-			    u64 attr_valid, u64 attr_version);
+int fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
+			   u64 attr_valid, u64 attr_version);
 
-void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
-				   u64 attr_valid);
+int fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
+				  u64 attr_valid);
 
 /**
  * Initialize the client device
@@ -855,7 +859,7 @@ struct fuse_conn *fuse_conn_get(struct fuse_conn *fc);
 /**
  * Initialize fuse_conn
  */
-void fuse_conn_init(struct fuse_conn *fc);
+void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns);
 
 /**
  * Release reference to fuse_conn
diff --git a/fs/fuse/inode.c b/fs/fuse/inode.c
index 2f31874ea9db..ea61a7639a8e 100644
--- a/fs/fuse/inode.c
+++ b/fs/fuse/inode.c
@@ -155,11 +155,22 @@ static ino_t fuse_squash_ino(u64 ino64)
 	return ino;
 }
 
-void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
-				   u64 attr_valid)
+int fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
+				  u64 attr_valid)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_inode *fi = get_fuse_inode(inode);
+	kuid_t uid;
+	kgid_t gid;
+
+	uid = make_kuid(fc->user_ns, attr->uid);
+	gid = make_kgid(fc->user_ns, attr->gid);
+	if (!uid_valid(uid) || !gid_valid(gid)) {
+		make_bad_inode(inode);
+		return -EIO;
+	}
+	inode->i_uid = uid;
+	inode->i_gid = gid;
 
 	fi->attr_version = ++fc->attr_version;
 	fi->i_time = attr_valid;
@@ -167,8 +178,6 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 	inode->i_ino     = fuse_squash_ino(attr->ino);
 	inode->i_mode    = (inode->i_mode & S_IFMT) | (attr->mode & 07777);
 	set_nlink(inode, attr->nlink);
-	inode->i_uid     = make_kuid(&init_user_ns, attr->uid);
-	inode->i_gid     = make_kgid(&init_user_ns, attr->gid);
 	inode->i_blocks  = attr->blocks;
 	inode->i_atime.tv_sec   = attr->atime;
 	inode->i_atime.tv_nsec  = attr->atimensec;
@@ -195,26 +204,32 @@ void fuse_change_attributes_common(struct inode *inode, struct fuse_attr *attr,
 		inode->i_mode &= ~S_ISVTX;
 
 	fi->orig_ino = attr->ino;
+	return 0;
 }
 
-void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
-			    u64 attr_valid, u64 attr_version)
+int fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
+			   u64 attr_valid, u64 attr_version)
 {
 	struct fuse_conn *fc = get_fuse_conn(inode);
 	struct fuse_inode *fi = get_fuse_inode(inode);
 	bool is_wb = fc->writeback_cache;
 	loff_t oldsize;
 	struct timespec old_mtime;
+	int err;
 
 	spin_lock(&fc->lock);
 	if ((attr_version != 0 && fi->attr_version > attr_version) ||
 	    test_bit(FUSE_I_SIZE_UNSTABLE, &fi->state)) {
 		spin_unlock(&fc->lock);
-		return;
+		return 0;
 	}
 
 	old_mtime = inode->i_mtime;
-	fuse_change_attributes_common(inode, attr, attr_valid);
+	err = fuse_change_attributes_common(inode, attr, attr_valid);
+	if (err) {
+		spin_unlock(&fc->lock);
+		return err;
+	}
 
 	oldsize = inode->i_size;
 	/*
@@ -249,6 +264,8 @@ void fuse_change_attributes(struct inode *inode, struct fuse_attr *attr,
 		if (inval)
 			invalidate_inode_pages2(inode->i_mapping);
 	}
+
+	return 0;
 }
 
 static void fuse_init_inode(struct inode *inode, struct fuse_attr *attr)
@@ -302,7 +319,7 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
  retry:
 	inode = iget5_locked(sb, nodeid, fuse_inode_eq, fuse_inode_set, &nodeid);
 	if (!inode)
-		return NULL;
+		return ERR_PTR(-ENOMEM);
 
 	if ((inode->i_state & I_NEW)) {
 		inode->i_flags |= S_NOATIME;
@@ -318,11 +335,23 @@ struct inode *fuse_iget(struct super_block *sb, u64 nodeid,
 		goto retry;
 	}
 
+	/*
+	 * Must do this before incrementing nlookup, as the caller will
+	 * send a forget for the node if this function fails.
+	 */
+	if (fuse_change_attributes(inode, attr, attr_valid, attr_version)) {
+		/*
+		 * inode_make_bad() already called by
+		 * fuse_change_attributes()
+		 */
+		iput(inode);
+		return ERR_PTR(-EIO);
+	}
+
 	fi = get_fuse_inode(inode);
 	spin_lock(&fc->lock);
 	fi->nlookup++;
 	spin_unlock(&fc->lock);
-	fuse_change_attributes(inode, attr, attr_valid, attr_version);
 
 	return inode;
 }
@@ -467,12 +496,15 @@ static int fuse_match_uint(substring_t *s, unsigned int *res)
 	return err;
 }
 
-static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
+static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev,
+			  struct user_namespace *user_ns)
 {
 	char *p;
 	memset(d, 0, sizeof(struct fuse_mount_data));
 	d->max_read = ~0;
 	d->blksize = FUSE_DEFAULT_BLKSIZE;
+	d->user_id = make_kuid(user_ns, 0);
+	d->group_id = make_kgid(user_ns, 0);
 
 	while ((p = strsep(&opt, ",")) != NULL) {
 		int token;
@@ -503,7 +535,7 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 		case OPT_USER_ID:
 			if (fuse_match_uint(&args[0], &uv))
 				return 0;
-			d->user_id = make_kuid(current_user_ns(), uv);
+			d->user_id = make_kuid(user_ns, uv);
 			if (!uid_valid(d->user_id))
 				return 0;
 			d->user_id_present = 1;
@@ -512,7 +544,7 @@ static int parse_fuse_opt(char *opt, struct fuse_mount_data *d, int is_bdev)
 		case OPT_GROUP_ID:
 			if (fuse_match_uint(&args[0], &uv))
 				return 0;
-			d->group_id = make_kgid(current_user_ns(), uv);
+			d->group_id = make_kgid(user_ns, uv);
 			if (!gid_valid(d->group_id))
 				return 0;
 			d->group_id_present = 1;
@@ -555,8 +587,10 @@ static int fuse_show_options(struct seq_file *m, struct dentry *root)
 	struct super_block *sb = root->d_sb;
 	struct fuse_conn *fc = get_fuse_conn_super(sb);
 
-	seq_printf(m, ",user_id=%u", from_kuid_munged(&init_user_ns, fc->user_id));
-	seq_printf(m, ",group_id=%u", from_kgid_munged(&init_user_ns, fc->group_id));
+	seq_printf(m, ",user_id=%u",
+		   from_kuid_munged(fc->user_ns, fc->user_id));
+	seq_printf(m, ",group_id=%u",
+		   from_kgid_munged(fc->user_ns, fc->group_id));
 	if (fc->flags & FUSE_DEFAULT_PERMISSIONS)
 		seq_puts(m, ",default_permissions");
 	if (fc->flags & FUSE_ALLOW_OTHER)
@@ -587,7 +621,7 @@ static void fuse_pqueue_init(struct fuse_pqueue *fpq)
 	fpq->connected = 1;
 }
 
-void fuse_conn_init(struct fuse_conn *fc)
+void fuse_conn_init(struct fuse_conn *fc, struct user_namespace *user_ns)
 {
 	memset(fc, 0, sizeof(*fc));
 	spin_lock_init(&fc->lock);
@@ -611,6 +645,7 @@ void fuse_conn_init(struct fuse_conn *fc)
 	fc->attr_version = 1;
 	get_random_bytes(&fc->scramble_key, sizeof(fc->scramble_key));
 	fc->pid_ns = get_pid_ns(task_active_pid_ns(current));
+	fc->user_ns = get_user_ns(user_ns);
 }
 EXPORT_SYMBOL_GPL(fuse_conn_init);
 
@@ -620,6 +655,7 @@ void fuse_conn_put(struct fuse_conn *fc)
 		if (fc->destroy_req)
 			fuse_request_free(fc->destroy_req);
 		put_pid_ns(fc->pid_ns);
+		put_user_ns(fc->user_ns);
 		fc->release(fc);
 	}
 }
@@ -635,12 +671,15 @@ EXPORT_SYMBOL_GPL(fuse_conn_get);
 static struct inode *fuse_get_root_inode(struct super_block *sb, unsigned mode)
 {
 	struct fuse_attr attr;
+	struct inode *inode;
+
 	memset(&attr, 0, sizeof(attr));
 
 	attr.mode = mode;
 	attr.ino = FUSE_ROOT_ID;
 	attr.nlink = 1;
-	return fuse_iget(sb, 1, 0, &attr, 0, 0);
+	inode = fuse_iget(sb, 1, 0, &attr, 0, 0);
+	return IS_ERR(inode) ? NULL : inode;
 }
 
 struct fuse_inode_handle {
@@ -1046,7 +1085,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 
 	sb->s_flags &= ~(MS_NOSEC | MS_I_VERSION);
 
-	if (!parse_fuse_opt(data, &d, is_bdev))
+	if (!parse_fuse_opt(data, &d, is_bdev, sb->s_user_ns))
 		goto err;
 
 	if (is_bdev) {
@@ -1070,8 +1109,12 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 	if (!file)
 		goto err;
 
-	if ((file->f_op != &fuse_dev_operations) ||
-	    (file->f_cred->user_ns != &init_user_ns))
+	/*
+	 * Require mount to happen from the same user namespace which
+	 * opened /dev/fuse to prevent potential attacks.
+	 */
+	if (file->f_op != &fuse_dev_operations ||
+	    file->f_cred->user_ns != sb->s_user_ns)
 		goto err_fput;
 
 	fc = kmalloc(sizeof(*fc), GFP_KERNEL);
@@ -1079,7 +1122,7 @@ static int fuse_fill_super(struct super_block *sb, void *data, int silent)
 	if (!fc)
 		goto err_fput;
 
-	fuse_conn_init(fc);
+	fuse_conn_init(fc, sb->s_user_ns);
 	fc->release = fuse_free_conn;
 
 	fud = fuse_dev_alloc(fc);
