Amir Goldstein 7e63c87fc2 ovl: fix lookup failure on multi lower squashfs ... In the past, overlayfs required that lower fs have non null uuid in order to support nfs export and decode copy up origin file handles. Commit 9df085f3c9 ("ovl: relax requirement for non null uuid of lower fs") relaxed this requirement for nfs export support, as long as uuid (even if null) is unique among all lower fs. However, said commit unintentionally also relaxed the non null uuid requirement for decoding copy up origin file handles, regardless of the unique uuid requirement. Amend this mistake by disabling decoding of copy up origin file handle from lower fs with a conflicting uuid. We still encode copy up origin file handles from those fs, because file handles like those already exist in the wild and because they might provide useful information in the future. There is an unhandled corner case described by Miklos this way: - two filesystems, A and B, both have null uuid - upper layer is on A - lower layer 1 is also on A - lower layer 2 is on B In this case bad_uuid won't be set for B, because the check only involves the list of lower fs. Hence we'll try to decode a layer 2 origin on layer 1 and fail. We will deal with this corner case later. Reported-by: Colin Ian King <colin.king@canonical.com> Tested-by: Colin Ian King <colin.king@canonical.com> Link: https://lore.kernel.org/lkml/20191106234301.283006-1-colin.king@canonical.com/ Fixes: 9df085f3c9 ("ovl: relax requirement for non null uuid ...") Cc: stable@vger.kernel.org # v4.20+ Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>		2019-12-10 16:00:55 +01:00
..
copy_up.c	SPDX update for 5.2-rc6	2019-06-21 09:58:42 -07:00
dir.c	SPDX update for 5.2-rc6	2019-06-21 09:58:42 -07:00
export.c	ovl: Fix dereferencing possible ERR_PTR()	2019-09-11 16:11:45 +02:00
file.c	SPDX update for 5.2-rc6	2019-06-21 09:58:42 -07:00
inode.c	ovl: filter of trusted xattr results in audit	2019-09-11 16:11:45 +02:00
Kconfig	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
Makefile	treewide: Add SPDX license identifier - Makefile/Kconfig	2019-05-21 10:50:46 +02:00
namei.c	ovl: fix lookup failure on multi lower squashfs	2019-12-10 16:00:55 +01:00
overlayfs.h	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
ovl_entry.h	ovl: fix lookup failure on multi lower squashfs	2019-12-10 16:00:55 +01:00
readdir.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00
super.c	ovl: fix lookup failure on multi lower squashfs	2019-12-10 16:00:55 +01:00
util.c	treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 500	2019-06-19 17:09:55 +02:00