From 0f5d220b42fba0ab17a7353787be3c29bea92e30 Mon Sep 17 00:00:00 2001 From: Christian Brauner Date: Thu, 21 Jan 2021 14:19:40 +0100 Subject: ioctl: handle idmapped mounts Enable generic ioctls to handle idmapped mounts by passing down the mount's user namespace. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Link: https://lore.kernel.org/r/20210121131959.646623-22-christian.brauner@ubuntu.com Cc: Christoph Hellwig Cc: David Howells Cc: Al Viro Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig Reviewed-by: James Morris Signed-off-by: Christian Brauner --- fs/remap_range.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'fs/remap_range.c') diff --git a/fs/remap_range.c b/fs/remap_range.c index 29a4a4dbfe12..e4a5fdd7ad7b 100644 --- a/fs/remap_range.c +++ b/fs/remap_range.c @@ -432,13 +432,16 @@ EXPORT_SYMBOL(vfs_clone_file_range); /* Check whether we are allowed to dedupe the destination file */ static bool allow_file_dedupe(struct file *file) { + struct user_namespace *mnt_userns = file_mnt_user_ns(file); + struct inode *inode = file_inode(file); + if (capable(CAP_SYS_ADMIN)) return true; if (file->f_mode & FMODE_WRITE) return true; - if (uid_eq(current_fsuid(), file_inode(file)->i_uid)) + if (uid_eq(current_fsuid(), i_uid_into_mnt(mnt_userns, inode))) return true; - if (!inode_permission(&init_user_ns, file_inode(file), MAY_WRITE)) + if (!inode_permission(mnt_userns, inode, MAY_WRITE)) return true; return false; } -- cgit 1.4.1