1 files changed, 172 insertions, 40 deletions

diff --git a/fs/namespace.c b/fs/namespace.c
index 93c377816d75..6b0a17487d0f 100644
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -3901,7 +3901,7 @@ static struct mnt_namespace *alloc_mnt_ns(struct user_namespace *user_ns, bool a
 	}
 	new_ns->ns.ops = &mntns_operations;
 	if (!anon)
-		new_ns->seq = atomic64_add_return(1, &mnt_ns_seq);
+		new_ns->seq = atomic64_inc_return(&mnt_ns_seq);
 	refcount_set(&new_ns->ns.count, 1);
 	refcount_set(&new_ns->passive, 1);
 	new_ns->mounts = RB_ROOT;
@@ -3944,7 +3944,9 @@ struct mnt_namespace *copy_mnt_ns(unsigned long flags, struct mnt_namespace *ns,
 	new = copy_tree(old, old->mnt.mnt_root, copy_flags);
 	if (IS_ERR(new)) {
 		namespace_unlock();
-		free_mnt_ns(new_ns);
+		ns_free_inum(&new_ns->ns);
+		dec_mnt_namespaces(new_ns->ucounts);
+		mnt_ns_release(new_ns);
 		return ERR_CAST(new);
 	}
 	if (user_ns != ns->user_ns) {
@@ -4105,7 +4107,6 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags,
 	struct file *file;
 	struct path newmount;
 	struct mount *mnt;
-	struct fd f;
 	unsigned int mnt_flags = 0;
 	long ret;
 
@@ -4133,19 +4134,18 @@ SYSCALL_DEFINE3(fsmount, int, fs_fd, unsigned int, flags,
 		return -EINVAL;
 	}
 
-	f = fdget(fs_fd);
-	if (!fd_file(f))
+	CLASS(fd, f)(fs_fd);
+	if (fd_empty(f))
 		return -EBADF;
 
-	ret = -EINVAL;
 	if (fd_file(f)->f_op != &fscontext_fops)
-		goto err_fsfd;
+		return -EINVAL;
 
 	fc = fd_file(f)->private_data;
 
 	ret = mutex_lock_interruptible(&fc->uapi_mutex);
 	if (ret < 0)
-		goto err_fsfd;
+		return ret;
 
 	/* There must be a valid superblock or we can't mount it */
 	ret = -EINVAL;
@@ -4212,8 +4212,6 @@ err_path:
 	path_put(&newmount);
 err_unlock:
 	mutex_unlock(&fc->uapi_mutex);
-err_fsfd:
-	fdput(f);
 	return ret;
 }
 
@@ -4668,10 +4666,8 @@ out:
 static int build_mount_idmapped(const struct mount_attr *attr, size_t usize,
 				struct mount_kattr *kattr, unsigned int flags)
 {
-	int err = 0;
 	struct ns_common *ns;
 	struct user_namespace *mnt_userns;
-	struct fd f;
 
 	if (!((attr->attr_set | attr->attr_clr) & MOUNT_ATTR_IDMAP))
 		return 0;
@@ -4687,20 +4683,16 @@ static int build_mount_idmapped(const struct mount_attr *attr, size_t usize,
 	if (attr->userns_fd > INT_MAX)
 		return -EINVAL;
 
-	f = fdget(attr->userns_fd);
-	if (!fd_file(f))
+	CLASS(fd, f)(attr->userns_fd);
+	if (fd_empty(f))
 		return -EBADF;
 
-	if (!proc_ns_file(fd_file(f))) {
-		err = -EINVAL;
-		goto out_fput;
-	}
+	if (!proc_ns_file(fd_file(f)))
+		return -EINVAL;
 
 	ns = get_proc_ns(file_inode(fd_file(f)));
-	if (ns->ops->type != CLONE_NEWUSER) {
-		err = -EINVAL;
-		goto out_fput;
-	}
+	if (ns->ops->type != CLONE_NEWUSER)
+		return -EINVAL;
 
 	/*
 	 * The initial idmapping cannot be used to create an idmapped
@@ -4711,22 +4703,15 @@ static int build_mount_idmapped(const struct mount_attr *attr, size_t usize,
 	 * result.
 	 */
 	mnt_userns = container_of(ns, struct user_namespace, ns);
-	if (mnt_userns == &init_user_ns) {
-		err = -EPERM;
-		goto out_fput;
-	}
+	if (mnt_userns == &init_user_ns)
+		return -EPERM;
 
 	/* We're not controlling the target namespace. */
-	if (!ns_capable(mnt_userns, CAP_SYS_ADMIN)) {
-		err = -EPERM;
-		goto out_fput;
-	}
+	if (!ns_capable(mnt_userns, CAP_SYS_ADMIN))
+		return -EPERM;
 
 	kattr->mnt_userns = get_user_ns(mnt_userns);
-
-out_fput:
-	fdput(f);
-	return err;
+	return 0;
 }
 
 static int build_mount_kattr(const struct mount_attr *attr, size_t usize,
@@ -5004,6 +4989,40 @@ static int statmount_fs_type(struct kstatmount *s, struct seq_file *seq)
 	return 0;
 }
 
+static void statmount_fs_subtype(struct kstatmount *s, struct seq_file *seq)
+{
+	struct super_block *sb = s->mnt->mnt_sb;
+
+	if (sb->s_subtype)
+		seq_puts(seq, sb->s_subtype);
+}
+
+static int statmount_sb_source(struct kstatmount *s, struct seq_file *seq)
+{
+	struct super_block *sb = s->mnt->mnt_sb;
+	struct mount *r = real_mount(s->mnt);
+
+	if (sb->s_op->show_devname) {
+		size_t start = seq->count;
+		int ret;
+
+		ret = sb->s_op->show_devname(seq, s->mnt->mnt_root);
+		if (ret)
+			return ret;
+
+		if (unlikely(seq_has_overflowed(seq)))
+			return -EAGAIN;
+
+		/* Unescape the result */
+		seq->buf[seq->count] = '\0';
+		seq->count = start;
+		seq_commit(seq, string_unescape_inplace(seq->buf + start, UNESCAPE_OCTAL));
+	} else if (r->mnt_devname) {
+		seq_puts(seq, r->mnt_devname);
+	}
+	return 0;
+}
+
 static void statmount_mnt_ns_id(struct kstatmount *s, struct mnt_namespace *ns)
 {
 	s->sm.mask |= STATMOUNT_MNT_NS_ID;
@@ -5038,35 +5057,134 @@ static int statmount_mnt_opts(struct kstatmount *s, struct seq_file *seq)
 	return 0;
 }
 
+static inline int statmount_opt_unescape(struct seq_file *seq, char *buf_start)
+{
+	char *buf_end, *opt_start, *opt_end;
+	int count = 0;
+
+	buf_end = seq->buf + seq->count;
+	*buf_end = '\0';
+	for (opt_start = buf_start + 1; opt_start < buf_end; opt_start = opt_end + 1) {
+		opt_end = strchrnul(opt_start, ',');
+		*opt_end = '\0';
+		buf_start += string_unescape(opt_start, buf_start, 0, UNESCAPE_OCTAL) + 1;
+		if (WARN_ON_ONCE(++count == INT_MAX))
+			return -EOVERFLOW;
+	}
+	seq->count = buf_start - 1 - seq->buf;
+	return count;
+}
+
+static int statmount_opt_array(struct kstatmount *s, struct seq_file *seq)
+{
+	struct vfsmount *mnt = s->mnt;
+	struct super_block *sb = mnt->mnt_sb;
+	size_t start = seq->count;
+	char *buf_start;
+	int err;
+
+	if (!sb->s_op->show_options)
+		return 0;
+
+	buf_start = seq->buf + start;
+	err = sb->s_op->show_options(seq, mnt->mnt_root);
+	if (err)
+		return err;
+
+	if (unlikely(seq_has_overflowed(seq)))
+		return -EAGAIN;
+
+	if (seq->count == start)
+		return 0;
+
+	err = statmount_opt_unescape(seq, buf_start);
+	if (err < 0)
+		return err;
+
+	s->sm.opt_num = err;
+	return 0;
+}
+
+static int statmount_opt_sec_array(struct kstatmount *s, struct seq_file *seq)
+{
+	struct vfsmount *mnt = s->mnt;
+	struct super_block *sb = mnt->mnt_sb;
+	size_t start = seq->count;
+	char *buf_start;
+	int err;
+
+	buf_start = seq->buf + start;
+
+	err = security_sb_show_options(seq, sb);
+	if (!err)
+		return err;
+
+	if (unlikely(seq_has_overflowed(seq)))
+		return -EAGAIN;
+
+	if (seq->count == start)
+		return 0;
+
+	err = statmount_opt_unescape(seq, buf_start);
+	if (err < 0)
+		return err;
+
+	s->sm.opt_sec_num = err;
+	return 0;
+}
+
 static int statmount_string(struct kstatmount *s, u64 flag)
 {
-	int ret;
+	int ret = 0;
 	size_t kbufsize;
 	struct seq_file *seq = &s->seq;
 	struct statmount *sm = &s->sm;
+	u32 start = seq->count;
 
 	switch (flag) {
 	case STATMOUNT_FS_TYPE:
-		sm->fs_type = seq->count;
+		sm->fs_type = start;
 		ret = statmount_fs_type(s, seq);
 		break;
 	case STATMOUNT_MNT_ROOT:
-		sm->mnt_root = seq->count;
+		sm->mnt_root = start;
 		ret = statmount_mnt_root(s, seq);
 		break;
 	case STATMOUNT_MNT_POINT:
-		sm->mnt_point = seq->count;
+		sm->mnt_point = start;
 		ret = statmount_mnt_point(s, seq);
 		break;
 	case STATMOUNT_MNT_OPTS:
-		sm->mnt_opts = seq->count;
+		sm->mnt_opts = start;
 		ret = statmount_mnt_opts(s, seq);
 		break;
+	case STATMOUNT_OPT_ARRAY:
+		sm->opt_array = start;
+		ret = statmount_opt_array(s, seq);
+		break;
+	case STATMOUNT_OPT_SEC_ARRAY:
+		sm->opt_sec_array = start;
+		ret = statmount_opt_sec_array(s, seq);
+		break;
+	case STATMOUNT_FS_SUBTYPE:
+		sm->fs_subtype = start;
+		statmount_fs_subtype(s, seq);
+		break;
+	case STATMOUNT_SB_SOURCE:
+		sm->sb_source = start;
+		ret = statmount_sb_source(s, seq);
+		break;
 	default:
 		WARN_ON_ONCE(true);
 		return -EINVAL;
 	}
 
+	/*
+	 * If nothing was emitted, return to avoid setting the flag
+	 * and terminating the buffer.
+	 */
+	if (seq->count == start)
+		return ret;
 	if (unlikely(check_add_overflow(sizeof(*sm), seq->count, &kbufsize)))
 		return -EOVERFLOW;
 	if (kbufsize >= s->bufsize)
@@ -5201,6 +5319,18 @@ static int do_statmount(struct kstatmount *s, u64 mnt_id, u64 mnt_ns_id,
 	if (!err && s->mask & STATMOUNT_MNT_OPTS)
 		err = statmount_string(s, STATMOUNT_MNT_OPTS);
 
+	if (!err && s->mask & STATMOUNT_OPT_ARRAY)
+		err = statmount_string(s, STATMOUNT_OPT_ARRAY);
+
+	if (!err && s->mask & STATMOUNT_OPT_SEC_ARRAY)
+		err = statmount_string(s, STATMOUNT_OPT_SEC_ARRAY);
+
+	if (!err && s->mask & STATMOUNT_FS_SUBTYPE)
+		err = statmount_string(s, STATMOUNT_FS_SUBTYPE);
+
+	if (!err && s->mask & STATMOUNT_SB_SOURCE)
+		err = statmount_string(s, STATMOUNT_SB_SOURCE);
+
 	if (!err && s->mask & STATMOUNT_MNT_NS_ID)
 		statmount_mnt_ns_id(s, ns);
 
@@ -5222,7 +5352,9 @@ static inline bool retry_statmount(const long ret, size_t *seq_size)
 }
 
 #define STATMOUNT_STRING_REQ (STATMOUNT_MNT_ROOT | STATMOUNT_MNT_POINT | \
-			      STATMOUNT_FS_TYPE | STATMOUNT_MNT_OPTS)
+			      STATMOUNT_FS_TYPE | STATMOUNT_MNT_OPTS | \
+			      STATMOUNT_FS_SUBTYPE | STATMOUNT_SB_SOURCE | \
+			      STATMOUNT_OPT_ARRAY | STATMOUNT_OPT_SEC_ARRAY)
 
 static int prepare_kstatmount(struct kstatmount *ks, struct mnt_id_req *kreq,
 			      struct statmount __user *buf, size_t bufsize,