linux-toradex.git/fs/overlayfs, branch v4.4.151

ovl: filter trusted xattr for non-admin

2018-04-13T17:50:14+00:00

[ 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: fix failure to fsync lower dir

2018-02-16T19:09:47+00:00

commit d796e77f1dd541fe34481af2eee6454688d13982 upstream.

As a writable mount, it is not expected for overlayfs to return
EINVAL/EROFS for fsync, even if dir/file is not changed.

This commit fixes the case of fsync of directory, which is easier to
address, because overlayfs already implements fsync file operation for
directories.

The problem reported by Raphael is that new PostgreSQL 10.0 with a
database in overlayfs where lower layer in squashfs fails to start.
The failure is due to fsync error, when PostgreSQL does fsync on all
existing db directories on startup and a specific directory exists
lower layer with no changes.

Reported-by: Raphael Hertzog 
Signed-off-by: Amir Goldstein 
Tested-by: Raphaël Hertzog 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

ovl: fsync after copy-up

2016-11-10T15:36:34+00:00

commit 641089c1549d8d3df0b047b5de7e9a111362cdce upstream.

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 
Signed-off-by: Greg Kroah-Hartman

ovl: copy_up_xattr(): use strnlen

2016-10-28T07:01:30+00:00

commit 8b326c61de08f5ca4bc454a168f19e7e43c4cc2a upstream.

Be defensive about what underlying fs provides us in the returned xattr
list buffer.  strlen() may overrun the buffer, so use strnlen() and WARN if
the contents are not properly null terminated.

Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman

ovl: Fix info leak in ovl_lookup_temp()

2016-10-28T07:01:30+00:00

commit 6a45b3628ce4dcf7498b39c87d475bab6e2a9b24 upstream.

The function uses the memory address of a struct dentry as unique id.
While the address-based directory entry is only visible to root it is IMHO
still worth fixing since the temporary name does not have to be a kernel
address.  It can be any unique number.  Replace it by an atomic integer
which is allowed to wrap around.

Signed-off-by: Richard Weinberger 
Reviewed-by: Kees Cook 
Signed-off-by: Miklos Szeredi 
Fixes: e9be9d5e76e3 ("overlay filesystem")
Signed-off-by: Greg Kroah-Hartman

ovl: fix workdir creation

2016-09-15T06:27:52+00:00

commit e1ff3dd1ae52cef5b5373c8cc4ad949c2c25a71c upstream.

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")
Signed-off-by: Greg Kroah-Hartman

ovl: listxattr: use strnlen()

2016-09-15T06:27:52+00:00

commit 7cb35119d067191ce9ebc380a599db0b03cbd9d9 upstream.

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 
Signed-off-by: Greg Kroah-Hartman

ovl: remove posix_acl_default from workdir

2016-09-15T06:27:52+00:00

commit c11b9fdd6a612f376a5e886505f1c54c16d8c380 upstream.

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 
Signed-off-by: Greg Kroah-Hartman

ovl: don't copy up opaqueness

2016-09-15T06:27:52+00:00

commit 0956254a2d5b9e2141385514553aeef694dfe3b5 upstream.

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 
Signed-off-by: Greg Kroah-Hartman

ovl: disallow overlayfs as upperdir

2016-08-20T16:09:19+00:00

commit 76bc8e2843b66f8205026365966b49ec6da39ae7 upstream.

This does not work and does not make sense.  So instead of fixing it
(probably not hard) just disallow.

Reported-by: Andrei Vagin 
Signed-off-by: Miklos Szeredi 
Signed-off-by: Greg Kroah-Hartman