kernel.git/fs/overlayfs, branch linux-3.18.y

ovl: fix open in stacked overlay

2018-11-10T15:39:20Z

[ Upstream commit 1c8a47df36d72ace8cf78eb6c228aa0f8027d3c2 ] If two overlayfs filesystems are stacked on top of each other, then we need recursion in ovl_d_select_inode(). I guess d_backing_inode() is supposed to do that. But currently it doesn't and that functionality is open coded in vfs_open(). This is now copied into ovl_d_select_inode() to fix this regression. Reported-by: Alban Crequy Signed-off-by: Miklos Szeredi Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay...") Cc: David Howells Cc: # v4.2+ Signed-off-by: Sasha Levin

ovl: filter trusted xattr for non-admin

2018-04-13T17:52:16Z

[ Upstream commit a082c6f680da298cf075886ff032f32ccb7c5e1a ] Filesystems filter out extended attributes in the "trusted." domain for unprivlieged callers. Overlay calls underlying filesystem's method with elevated privs, so need to do the filtering in overlayfs too. Signed-off-by: Miklos Szeredi Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman

ovl: fsync after copy-up

2016-11-24T04:09:18Z

[ Upstream commit 641089c1549d8d3df0b047b5de7e9a111362cdce ] Make sure the copied up file hits the disk before renaming to the final destination. If this is not done then the copy-up may corrupt the data in the file in case of a crash. Signed-off-by: Miklos Szeredi Cc: Signed-off-by: Sasha Levin

ovl: fix workdir creation

2016-09-22T17:25:10Z

[ Upstream commit e1ff3dd1ae52cef5b5373c8cc4ad949c2c25a71c ] Workdir creation fails in latest kernel. Fix by allowing EOPNOTSUPP as a valid return value from vfs_removexattr(XATTR_NAME_POSIX_ACL_*). Upper filesystem may not support ACL and still be perfectly able to support overlayfs. Reported-by: Martin Ziegler Signed-off-by: Miklos Szeredi Fixes: c11b9fdd6a61 ("ovl: remove posix_acl_default from workdir") Cc: Signed-off-by: Sasha Levin

ovl: listxattr: use strnlen()

2016-09-15T22:54:06Z

[ Upstream commit 7cb35119d067191ce9ebc380a599db0b03cbd9d9 ] Be defensive about what underlying fs provides us in the returned xattr list buffer. If it's not properly null terminated, bail out with a warning insead of BUG. Signed-off-by: Miklos Szeredi Cc: Signed-off-by: Sasha Levin

ovl: remove posix_acl_default from workdir

2016-09-15T22:54:06Z

[ Upstream commit c11b9fdd6a612f376a5e886505f1c54c16d8c380 ] Clear out posix acl xattrs on workdir and also reset the mode after creation so that an inherited sgid bit is cleared. Signed-off-by: Miklos Szeredi Cc: Signed-off-by: Sasha Levin

ovl: don't copy up opaqueness

2016-09-12T18:53:02Z

[ Upstream commit 0956254a2d5b9e2141385514553aeef694dfe3b5 ] When a copy up of a directory occurs which has the opaque xattr set, the xattr remains in the upper directory. The immediate behavior with overlayfs is that the upper directory is not treated as opaque, however after a remount the opaque flag is used and upper directory is treated as opaque. This causes files created in the lower layer to be hidden when using multiple lower directories. Fix by not copying up the opaque flag. To reproduce: ----8<---------8<---------8<---------8<---------8<---------8<---- mkdir -p l/d/s u v w mnt mount -t overlay overlay -olowerdir=l,upperdir=u,workdir=w mnt rm -rf mnt/d/ mkdir -p mnt/d/n umount mnt mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt touch mnt/d/foo umount mnt mount -t overlay overlay -olowerdir=u:l,upperdir=v,workdir=w mnt ls mnt/d ----8<---------8<---------8<---------8<---------8<---------8<---- output should be: "foo n" Reported-by: Derek McGowan Link: https://bugzilla.kernel.org/show_bug.cgi?id=151291 Signed-off-by: Miklos Szeredi Cc: Signed-off-by: Sasha Levin

ovl: verify upper dentry in ovl_remove_and_whiteout()

2016-08-08T01:59:02Z

[ Upstream commit cfc9fde0b07c3b44b570057c5f93dda59dca1c94 ] The upper dentry may become stale before we call ovl_lock_rename_workdir. For example, someone could (mistakenly or maliciously) manually unlink(2) it directly from upperdir. To ensure it is not stale, let's lookup it after ovl_lock_rename_workdir and and check if it matches the upper dentry. Essentially, it is the same problem and similar solution as in commit 11f3710417d0 ("ovl: verify upper dentry before unlink and rename"). Signed-off-by: Maxim Patlasov Signed-off-by: Miklos Szeredi Cc: Signed-off-by: Sasha Levin

ovl: Copy up underlying inode's ->i_mode to overlay inode

2016-08-08T01:44:56Z

[ Upstream commit 07a2daab49c549a37b5b744cbebb6e3f445f12bc ] Right now when a new overlay inode is created, we initialize overlay inode's ->i_mode from underlying inode ->i_mode but we retain only file type bits (S_IFMT) and discard permission bits. This patch changes it and retains permission bits too. This should allow overlay to do permission checks on overlay inode itself in task context. [SzM] It also fixes clearing suid/sgid bits on write. Signed-off-by: Vivek Goyal Reported-by: Eryu Guan Signed-off-by: Miklos Szeredi Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Cc: Signed-off-by: Sasha Levin

ovl: handle ATTR_KILL*

2016-08-08T01:44:50Z

[ Upstream commit b99c2d913810e56682a538c9f2394d76fca808f8 ] Before 4bacc9c9234c ("overlayfs: Make f_path...") file->f_path pointed to the underlying file, hence suid/sgid removal on write worked fine. After that patch file->f_path pointed to the overlay file, and the file mode bits weren't copied to overlay_inode->i_mode. So the suid/sgid removal simply stopped working. The fix is to copy the mode bits, but then ovl_setattr() needs to clear ATTR_MODE to avoid the BUG() in notify_change(). So do this first, then in the next patch copy the mode. Reported-by: Eryu Guan Signed-off-by: Miklos Szeredi Fixes: 4bacc9c9234c ("overlayfs: Make f_path always point to the overlay and f_inode to the underlay") Cc: Signed-off-by: Sasha Levin