Merge tag 'ovl-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs

Pull overlayfs update from Miklos Szeredi:

 - Fix a couple of bugs found by syzbot

 - Don't ingore some open flags set by fcntl(F_SETFL)

 - Fix failure to create a hard link in certain cases

 - Use type safe helpers for some mnt_userns transformations

 - Improve performance of mount

 - Misc cleanups

* tag 'ovl-update-6.2' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs:
  ovl: Kconfig: Fix spelling mistake "undelying" -> "underlying"
  ovl: use inode instead of dentry where possible
  ovl: Add comment on upperredirect reassignment
  ovl: use plain list filler in indexdir and workdir cleanup
  ovl: do not reconnect upper index records in ovl_indexdir_cleanup()
  ovl: fix comment typos
  ovl: port to vfs{g,u}id_t and associated helpers
  ovl: Use ovl mounter's fsuid and fsgid in ovl_link()
  ovl: Use "buf" flexible array for memcpy() destination
  ovl: update ->f_iocb_flags when ovl_change_flags() modifies ->f_flags
  ovl: fix use inode directly in rcu-walk mode

1 files changed, 30 insertions, 16 deletions

diff --git a/fs/overlayfs/dir.c b/fs/overlayfs/dir.c
index cbb569d5d234..f61e37f4c8ff 100644
--- a/fs/overlayfs/dir.c
+++ b/fs/overlayfs/dir.c
@@ -576,28 +576,42 @@ static int ovl_create_or_link(struct dentry *dentry, struct inode *inode,
 			goto out_revert_creds;
 	}
 
-	err = -ENOMEM;
-	override_cred = prepare_creds();
-	if (override_cred) {
+	if (!attr->hardlink) {
+		err = -ENOMEM;
+		override_cred = prepare_creds();
+		if (!override_cred)
+			goto out_revert_creds;
+		/*
+		 * In the creation cases(create, mkdir, mknod, symlink),
+		 * ovl should transfer current's fs{u,g}id to underlying
+		 * fs. Because underlying fs want to initialize its new
+		 * inode owner using current's fs{u,g}id. And in this
+		 * case, the @inode is a new inode that is initialized
+		 * in inode_init_owner() to current's fs{u,g}id. So use
+		 * the inode's i_{u,g}id to override the cred's fs{u,g}id.
+		 *
+		 * But in the other hardlink case, ovl_link() does not
+		 * create a new inode, so just use the ovl mounter's
+		 * fs{u,g}id.
+		 */
 		override_cred->fsuid = inode->i_uid;
 		override_cred->fsgid = inode->i_gid;
-		if (!attr->hardlink) {
-			err = security_dentry_create_files_as(dentry,
-					attr->mode, &dentry->d_name, old_cred,
-					override_cred);
-			if (err) {
-				put_cred(override_cred);
-				goto out_revert_creds;
-			}
+		err = security_dentry_create_files_as(dentry,
+				attr->mode, &dentry->d_name, old_cred,
+				override_cred);
+		if (err) {
+			put_cred(override_cred);
+			goto out_revert_creds;
 		}
 		put_cred(override_creds(override_cred));
 		put_cred(override_cred);
-
-		if (!ovl_dentry_is_whiteout(dentry))
-			err = ovl_create_upper(dentry, inode, attr);
-		else
-			err = ovl_create_over_whiteout(dentry, inode, attr);
 	}
+
+	if (!ovl_dentry_is_whiteout(dentry))
+		err = ovl_create_upper(dentry, inode, attr);
+	else
+		err = ovl_create_over_whiteout(dentry, inode, attr);
+
 out_revert_creds:
 	revert_creds(old_cred);
 	return err;