Zheng Liang 1caaa82091 ovl: fix missing negative dentry check in ovl_rename() ... commit a295aef603 upstream. The following reproducer mkdir lower upper work merge touch lower/old touch lower/new mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merge rm merge/new mv merge/old merge/new & unlink upper/new may result in this race: PROCESS A: rename("merge/old", "merge/new"); overwrite=true,ovl_lower_positive(old)=true, ovl_dentry_is_whiteout(new)=true -> flags |= RENAME_EXCHANGE PROCESS B: unlink("upper/new"); PROCESS A: lookup newdentry in new_upperdir call vfs_rename() with negative newdentry and RENAME_EXCHANGE Fix by adding the missing check for negative newdentry. Signed-off-by: Zheng Liang <zhengliang6@huawei.com> Fixes: e9be9d5e76 ("overlay filesystem") Cc: <stable@vger.kernel.org> # v3.18 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2021-10-17 10:08:32 +02:00
..
copy_up.c	ovl: skip getxattr of security labels	2021-02-23 14:00:31 +01:00
dir.c	ovl: fix missing negative dentry check in ovl_rename()	2021-10-17 10:08:32 +02:00
inode.c	ovl: perform vfs_getxattr() with mounter creds	2021-02-23 14:00:31 +01:00
Kconfig	ovl: introduce the inodes index dir feature	2017-07-04 22:03:17 +02:00
Makefile	ovl: split super.c	2016-12-16 11:02:56 +01:00
namei.c	ovl: fix error handling in ovl_verify_set_fh()	2018-11-21 09:24:04 +01:00
overlayfs.h	ovl: fix format of setxattr debug	2018-10-10 08:54:27 +02:00
ovl_entry.h	locking/barriers: Convert users of lockless_dereference() to READ_ONCE()	2017-12-25 14:26:21 +01:00
readdir.c	ovl: fix wrong use of impure dir cache in ovl_iterate()	2018-09-09 19:55:58 +02:00
super.c	ovl: Sync upper dirty data when syncing overlayfs	2018-08-03 07:50:43 +02:00
util.c	ovl: fix memory leak on unlink of indexed file	2018-10-10 08:54:27 +02:00