Fuse mounts without "allow_other" are off-limits to all non-owners. Yet it
makes sense to allow querying st_dev on the root, since this value is
provided by the kernel, not the userspace filesystem.
Allow statx(2) with a zero request mask to succeed on a fuse mounts for all
users.
Reported-by: Nikolaus Rath <Nikolaus@rath.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
struct inode *inode = d_inode(path->dentry);
struct fuse_conn *fc = get_fuse_conn(inode);
- if (!fuse_allow_current_process(fc))
+ if (!fuse_allow_current_process(fc)) {
+ if (!request_mask) {
+ /*
+ * If user explicitly requested *nothing* then don't
+ * error out, but return st_dev only.
+ */
+ stat->result_mask = 0;
+ stat->dev = inode->i_sb->s_dev;
+ return 0;
+ }
return -EACCES;
+ }
return fuse_update_get_attr(inode, NULL, stat, request_mask, flags);
}