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commit dd524b7f317de8d31d638cbfdc7be4cf9b770e42 upstream.
Some code paths cannot guarantee the inode have any dentry alias. So
WARN_ON() all !dentry may flood the kernel logs.
For example, when an overlayfs inode is watched by inotifywait (1), and
someone is trying to read the /proc/$(pidof inotifywait)/fdinfo/INOTIFY_FD,
at that time if the dentry has been reclaimed by kernel (such as
echo 2 > /proc/sys/vm/drop_caches), there will be a WARN_ON(). The
printed call stack would be like:
? show_mark_fhandle+0xf0/0xf0
show_mark_fhandle+0x4a/0xf0
? show_mark_fhandle+0xf0/0xf0
? seq_vprintf+0x30/0x50
? seq_printf+0x53/0x70
? show_mark_fhandle+0xf0/0xf0
inotify_fdinfo+0x70/0x90
show_fdinfo.isra.4+0x53/0x70
seq_show+0x130/0x170
seq_read+0x153/0x440
vfs_read+0x94/0x150
ksys_read+0x5f/0xe0
do_syscall_64+0x59/0x1e0
entry_SYSCALL_64_after_hwframe+0x44/0xa9
So let's drop WARN_ON() to avoid kernel log flooding.
Reported-by: Hongbo Yin <yinhongbo@bytedance.com>
Signed-off-by: Jiachen Zhang <zhangjiachen.jaycee@bytedance.com>
Signed-off-by: Tianci Zhang <zhangtianci.1997@bytedance.com>
Fixes: 8ed5eec9d6c4 ("ovl: encode pure upper file handles")
Cc: <stable@vger.kernel.org> # v4.16
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 1f5573cfe7a7056e80a92c7a037a3e69f3a13d1c upstream.
Syzbot triggered the following warning in ovl_workdir_create() ->
ovl_create_real():
if (!err && WARN_ON(!newdentry->d_inode)) {
The reason is that the cgroup2 filesystem returns from mkdir without
instantiating the new dentry.
Weird filesystems such as this will be rejected by overlayfs at a later
stage during setup, but to prevent such a warning, call ovl_mkdir_real()
directly from ovl_workdir_create() and reject this case early.
Reported-and-tested-by: syzbot+75eab84fd0af9e8bf66b@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 52d5a0c6bd8a89f460243ed937856354f8f253a3 upstream.
If function ovl_instantiate() returns an error, ovl_cleanup will be called
and try to remove newdentry from wdir, but the newdentry has been moved to
udir at this time. This will causes BUG_ON(victim->d_parent->d_inode !=
dir) in fs/namei.c:may_delete.
Signed-off-by: chenying <chenying.kernel@bytedance.com>
Fixes: 01b39dcc9568 ("ovl: use inode_insert5() to hash a newly created inode")
Link: https://lore.kernel.org/linux-unionfs/e6496a94-a161-dc04-c38a-d2544633acb4@bytedance.com/
Cc: <stable@vger.kernel.org> # v4.18
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 7b279bbfd2b230c7a210ff8f405799c7e46bbf48 upstream.
Smatch complains about missing that the ovl_override_creds() doesn't
have a matching revert_creds() if the dentry is disconnected. Fix this
by moving the ovl_override_creds() until after the disconnected check.
Fixes: aa3ff3c152ff ("ovl: copy up of disconnected dentries")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 708fa01597fa002599756bf56a96d0de1677375c upstream.
Commit 146d62e5a586 ("ovl: detect overlapping layers") made sure we don't
have overlapping layers, but it also broke the arguably valid use case of
mount -olowerdir=/,upperdir=/subdir,..
where upperdir overlaps lowerdir on the same filesystem. This has been
causing regressions.
Revert the check, but only for the specific case where upperdir and/or
workdir are subdirectories of lowerdir. Any other overlap (e.g. lowerdir
is subdirectory of upperdir, etc) case is crazy, so leave the check in
place for those.
Overlaps are detected at lookup time too, so reverting the mount time check
should be safe.
Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
Cc: <stable@vger.kernel.org> # v5.2
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit cef4cbff06fbc3be54d6d79ee139edecc2ee8598 upstream.
There was a syzbot report with this warning but insufficient information...
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 03fedf93593c82538b18476d8c4f0e8f8435ea70 ]
When inode has no listxattr op of its own (e.g. squashfs) vfs_listxattr
calls the LSM inode_listsecurity hooks to list the xattrs that LSMs will
intercept in inode_getxattr hooks.
When selinux LSM is installed but not initialized, it will list the
security.selinux xattr in inode_listsecurity, but will not intercept it
in inode_getxattr. This results in -ENODATA for a getxattr call for an
xattr returned by listxattr.
This situation was manifested as overlayfs failure to copy up lower
files from squashfs when selinux is built-in but not initialized,
because ovl_copy_xattr() iterates the lower inode xattrs by
vfs_listxattr() and vfs_getxattr().
ovl_copy_xattr() skips copy up of security labels that are indentified by
inode_copy_up_xattr LSM hooks, but it does that after vfs_getxattr().
Since we are not going to copy them, skip vfs_getxattr() of the security
labels.
Reported-by: Michael Labriola <michael.d.labriola@gmail.com>
Tested-by: Michael Labriola <michael.d.labriola@gmail.com>
Link: https://lore.kernel.org/linux-unionfs/2nv9d47zt7.fsf@aldarion.sourceruckus.org/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 554677b97257b0b69378bd74e521edb7e94769ff ]
The vfs_getxattr() in ovl_xattr_set() is used to check whether an xattr
exist on a lower layer file that is to be removed. If the xattr does not
exist, then no need to copy up the file.
This call of vfs_getxattr() wasn't wrapped in credential override, and this
is probably okay. But for consitency wrap this instance as well.
Reported-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 81a33c1ee941c3bb9ffc6bac8f676be13351344e upstream.
The check if user has changed the overlay file was wrong, causing unneeded
call to ovl_change_flags() including taking f_lock on every file access.
Fixes: d989903058a8 ("ovl: do not generate duplicate fsnotify events for "fake" path")
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 124c2de2c0aee96271e4ddab190083d8aa7aa71a upstream.
Decoding a lower directory file handle to overlay path with cold
inode/dentry cache may go as follows:
1. Decode real lower file handle to lower dir path
2. Check if lower dir is indexed (was copied up)
3. If indexed, get the upper dir path from index
4. Lookup upper dir path in overlay
5. If overlay path found, verify that overlay lower is the lower dir
from step 1
On failure to verify step 5 above, user will get an ESTALE error and a
WARN_ON will be printed.
A mismatch in step 5 could be a result of lower directory that was renamed
while overlay was offline, after that lower directory has been copied up
and indexed.
This is a scripted reproducer based on xfstest overlay/052:
# Create lower subdir
create_dirs
create_test_files $lower/lowertestdir/subdir
mount_dirs
# Copy up lower dir and encode lower subdir file handle
touch $SCRATCH_MNT/lowertestdir
test_file_handles $SCRATCH_MNT/lowertestdir/subdir -p -o $tmp.fhandle
# Rename lower dir offline
unmount_dirs
mv $lower/lowertestdir $lower/lowertestdir.new/
mount_dirs
# Attempt to decode lower subdir file handle
test_file_handles $SCRATCH_MNT -p -i $tmp.fhandle
Since this WARN_ON() can be triggered by user we need to relax it.
Fixes: 4b91c30a5a19 ("ovl: lookup connected ancestor of dir in inode cache")
Cc: <stable@vger.kernel.org> # v4.16+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 520da69d265a91c6536c63851cbb8a53946974f0 upstream.
In ovl_copy_xattr, if all the xattrs to be copied are overlayfs private
xattrs, the copy loop will terminate without assigning anything to the
error variable, thus returning an uninitialized value.
If ovl_copy_xattr is called from ovl_clear_empty, this uninitialized error
value is put into a pointer by ERR_PTR(), causing potential invalid memory
accesses down the line.
This commit initialize error with 0. This is the correct value because when
there's no xattr to copy, because all xattrs are private, ovl_copy_xattr
should succeed.
This bug is discovered with the help of INIT_STACK_ALL and clang.
Signed-off-by: Yuxuan Shui <yshuiv7@gmail.com>
Link: https://bugs.chromium.org/p/chromium/issues/detail?id=1050405
Fixes: 0956254a2d5b ("ovl: don't copy up opaqueness")
Cc: stable@vger.kernel.org # v4.8
Signed-off-by: Alexander Potapenko <glider@google.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 300b124fcf6ad2cd99a7b721e0f096785e0a3134 upstream.
Commit 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more
cases"), relaxed the condition nfs_export=on in order to set the value of
i_ino to xino map of real ino.
Specifically, it also relaxed the pre-condition that index=on for
consistent i_ino. This opened the corner case of lower hardlink in
ovl_get_inode(), which calls ovl_fill_inode() with ino=0 and then
ovl_init_inode() is called to set i_ino to lower real ino without the xino
mapping.
Pass the correct values of ino;fsid in this case to ovl_fill_inode(), so it
can initialize i_ino correctly.
Fixes: 6dde1e42f497 ("ovl: make i_ino consistent with st_ino in more ...")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 4c37e71b713ecffe81f8e6273c6835e54306d412 upstream.
The WARN_ON() that child entry is always on overlay st_dev became wrong
when we allowed this function to update d_ino in non-samefs setup with xino
enabled.
It is not true in case of xino bits overflow on a non-dir inode. Leave the
WARN_ON() only for directories, where assertion is still true.
Fixes: adbf4f7ea834 ("ovl: consistent d_ino for non-samefs with xino")
Cc: <stable@vger.kernel.org> # v4.17+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit a4ac9d45c0cd14a2adc872186431c79804b77dbf ]
ovl_lseek() is using ssize_t to return the value from vfs_llseek(). On a
32-bit kernel ssize_t is a 32-bit signed int, which overflows above 2 GB.
Assign the return value of vfs_llseek() to loff_t to fix this.
Reported-by: Boris Gjenero <boris.gjenero@gmail.com>
Fixes: 9e46b840c705 ("ovl: support stacked SEEK_HOLE/SEEK_DATA")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 6889ee5a53b8d969aa542047f5ac8acdc0e79a91 upstream.
In ovl_rename(), if new upper is hardlinked to old upper underneath
overlayfs before upper dirs are locked, user will get an ESTALE error
and a WARN_ON will be printed.
Changes to underlying layers while overlayfs is mounted may result in
unexpected behavior, but it shouldn't crash the kernel and it shouldn't
trigger WARN_ON() either, so relax this WARN_ON().
Reported-by: syzbot+bb1836a212e69f8e201a@syzkaller.appspotmail.com
Fixes: 804032fabb3b ("ovl: don't check rename to self")
Cc: <stable@vger.kernel.org> # v4.9+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 9c6d8f13e9da10a26ad7f0a020ef86e8ef142835 upstream.
On non-samefs overlay without xino, non pure upper inodes should use a
pseudo_dev assigned to each unique lower fs and pure upper inodes use the
real upper st_dev.
It is fine for an overlay pure upper inode to use the same st_dev;st_ino
values as the real upper inode, because the content of those two different
filesystem objects is always the same.
In this case, however:
- two filesystems, A and B
- upper layer is on A
- lower layer 1 is also on A
- lower layer 2 is on B
Non pure upper overlay inode, whose origin is in layer 1 will have the same
st_dev;st_ino values as the real lower inode. This may result with a false
positive results of 'diff' between the real lower and copied up overlay
inode.
Fix this by using the upper st_dev;st_ino values in this case. This breaks
the property of constant st_dev;st_ino across copy up of this case. This
breakage will be fixed by a later patch.
Fixes: 5148626b806a ("ovl: allocate anon bdev per unique lower fs")
Cc: stable@vger.kernel.org # v4.17+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5c2e9f346b815841f9bed6029ebcb06415caf640 upstream.
When filtering xattr list for reading, presence of trusted xattr
results in a security audit log. However, if there is other content
no errno will be set, and if there isn't, the errno will be -ENODATA
and not -EPERM as is usually associated with a lack of capability.
The check does not block the request to list the xattrs present.
Switch to ns_capable_noaudit to reflect a more appropriate check.
Signed-off-by: Mark Salyzyn <salyzyn@android.com>
Cc: linux-security-module@vger.kernel.org
Cc: kernel-team@android.com
Cc: stable@vger.kernel.org # v3.18+
Fixes: a082c6f680da ("ovl: filter trusted xattr for non-admin")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 97f024b9171e74c4443bbe8a8dce31b917f97ac5 upstream.
if ovl_encode_real_fh() fails, no memory was allocated
and the error in the error-valued pointer should be returned.
Fixes: 9b6faee07470 ("ovl: check ERR_PTR() return value from ovl_encode_fh()")
Signed-off-by: Ding Xiang <dingxiang@cmss.chinamobile.com>
Cc: <stable@vger.kernel.org> # v4.16+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 0be0bfd2de9dfdd2098a9c5b14bdd8f739c9165d upstream.
Once upon a time, commit 2cac0c00a6cd ("ovl: get exclusive ownership on
upper/work dirs") in v4.13 added some sanity checks on overlayfs layers.
This change caused a docker regression. The root cause was mount leaks
by docker, which as far as I know, still exist.
To mitigate the regression, commit 85fdee1eef1a ("ovl: fix regression
caused by exclusive upper/work dir protection") in v4.14 turned the
mount errors into warnings for the default index=off configuration.
Recently, commit 146d62e5a586 ("ovl: detect overlapping layers") in
v5.2, re-introduced exclusive upper/work dir checks regardless of
index=off configuration.
This changes the status quo and mount leak related bug reports have
started to re-surface. Restore the status quo to fix the regressions.
To clarify, index=off does NOT relax overlapping layers check for this
ovelayfs mount. index=off only relaxes exclusive upper/work dir checks
with another overlayfs mount.
To cover the part of overlapping layers detection that used the
exclusive upper/work dir checks to detect overlap with self upper/work
dir, add a trap also on the work base dir.
Link: https://github.com/moby/moby/issues/34672
Link: https://lore.kernel.org/linux-fsdevel/20171006121405.GA32700@veci.piliscsaba.szeredi.hu/
Link: https://github.com/containers/libpod/issues/3540
Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Tested-by: Colin Walters <walters@verbum.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 1dac6f5b0ed2601be21bb4e27a44b0c3e667b7f4 ]
gcc gets a bit confused by the logic in ovl_setup_trap() and
can't figure out whether the local 'trap' variable in the caller
was initialized or not:
fs/overlayfs/super.c: In function 'ovl_fill_super':
fs/overlayfs/super.c:1333:4: error: 'trap' may be used uninitialized in this function [-Werror=maybe-uninitialized]
iput(trap);
^~~~~~~~~~
fs/overlayfs/super.c:1312:17: note: 'trap' was declared here
Reword slightly to make it easier for the compiler to understand.
Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9179c21dc6ed1c993caa5fe4da876a6765c26af7 ]
NFS mounts can be disconnected from fs root. Don't fail the overlapping
layer check because of this.
The check is not authoritative anyway, since topology can change during or
after the check.
Reported-by: Antti Antinoja <antti@fennosys.fi>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 146d62e5a586 ("ovl: detect overlapping layers")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 146d62e5a5867fbf84490d82455718bfb10fe824 ]
Overlapping overlay layers are not supported and can cause unexpected
behavior, but overlayfs does not currently check or warn about these
configurations.
User is not supposed to specify the same directory for upper and
lower dirs or for different lower layers and user is not supposed to
specify directories that are descendants of each other for overlay
layers, but that is exactly what this zysbot repro did:
https://syzkaller.appspot.com/x/repro.syz?x=12c7a94f400000
Moving layer root directories into other layers while overlayfs
is mounted could also result in unexpected behavior.
This commit places "traps" in the overlay inode hash table.
Those traps are dummy overlay inodes that are hashed by the layers
root inodes.
On mount, the hash table trap entries are used to verify that overlay
layers are not overlapping. While at it, we also verify that overlay
layers are not overlapping with directories "in-use" by other overlay
instances as upperdir/workdir.
On lookup, the trap entries are used to verify that overlay layers
root inodes have not been moved into other layers after mount.
Some examples:
$ ./run --ov --samefs -s
...
( mkdir -p base/upper/0/u base/upper/0/w base/lower lower upper mnt
mount -o bind base/lower lower
mount -o bind base/upper upper
mount -t overlay none mnt ...
-o lowerdir=lower,upperdir=upper/0/u,workdir=upper/0/w)
$ umount mnt
$ mount -t overlay none mnt ...
-o lowerdir=base,upperdir=upper/0/u,workdir=upper/0/w
[ 94.434900] overlayfs: overlapping upperdir path
mount: mount overlay on mnt failed: Too many levels of symbolic links
$ mount -t overlay none mnt ...
-o lowerdir=upper/0/u,upperdir=upper/0/u,workdir=upper/0/w
[ 151.350132] overlayfs: conflicting lowerdir path
mount: none is already mounted or mnt busy
$ mount -t overlay none mnt ...
-o lowerdir=lower:lower/a,upperdir=upper/0/u,workdir=upper/0/w
[ 201.205045] overlayfs: overlapping lowerdir path
mount: mount overlay on mnt failed: Too many levels of symbolic links
$ mount -t overlay none mnt ...
-o lowerdir=lower,upperdir=upper/0/u,workdir=upper/0/w
$ mv base/upper/0/ base/lower/
$ find mnt/0
mnt/0
mnt/0/w
find: 'mnt/0/w/work': Too many levels of symbolic links
find: 'mnt/0/u': Too many levels of symbolic links
Reported-by: syzbot+9c69c282adc4edd2b540@syzkaller.appspotmail.com
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 6dde1e42f497b2d4e22466f23019016775607947 ]
Relax the condition that overlayfs supports nfs export, to require
that i_ino is consistent with st_ino/d_ino.
It is enough to require that st_ino and d_ino are consistent.
This fixes the failure of xfstest generic/504, due to mismatch of
st_ino to inode number in the output of /proc/locks.
Fixes: 12574a9f4c9c ("ovl: consistent i_ino for non-samefs with xino")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 941d935ac7636911a3fd8fa80e758e52b0b11e20 ]
The ioctl argument was parsed as the wrong type.
Fixes: b21d9c435f93 ("ovl: support the FS_IOC_FS[SG]ETXATTR ioctls")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b21d9c435f935014d3e3fa6914f2e4fbabb0e94d ]
They are the extended version of FS_IOC_FS[SG]ETFLAGS ioctls.
xfs_io -c "chattr <flags>" uses the new ioctls for setting flags.
This used to work in kernel pre v4.19, before stacked file ops
introduced the ovl_ioctl whitelist.
Reported-by: Dave Chinner <david@fromorbit.com>
Fixes: d1d04ef8572b ("ovl: stack file ops")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 9e46b840c7053b5f7a245e98cd239b60d189a96c upstream.
Overlay file f_pos is the master copy that is preserved
through copy up and modified on read/write, but only real
fs knows how to SEEK_HOLE/SEEK_DATA and real fs may impose
limitations that are more strict than ->s_maxbytes for specific
files, so we use the real file to perform seeks.
We do not call real fs for SEEK_CUR:0 query and for SEEK_SET:0
requests.
Fixes: d1d04ef8572b ("ovl: stack file ops")
Reported-by: Eddie Horng <eddiehorng.tw@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 98487de318a6f33312471ae1e2afa16fbf8361fe upstream.
We found that it return success when we set IMMUTABLE_FL flag to a file in
docker even though the docker didn't have the capability
CAP_LINUX_IMMUTABLE.
The commit d1d04ef8572b ("ovl: stack file ops") and dab5ca8fd9dd ("ovl: add
lsattr/chattr support") implemented chattr operations on a regular overlay
file. ovl_real_ioctl() overridden the current process's subjective
credentials with ofs->creator_cred which have the capability
CAP_LINUX_IMMUTABLE so that it will return success in
vfs_ioctl()->cap_capable().
Fix this by checking the capability before cred overridden. And here we
only care about APPEND_FL and IMMUTABLE_FL, so get these information from
inode.
[SzM: move check and call to underlying fs inside inode locked region to
prevent two such calls from racing with each other]
Signed-off-by: Jiufei Xue <jiufei.xue@linux.alibaba.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit d989903058a83e8536cc7aadf9256a47d5c173fe ]
Overlayfs "fake" path is used for stacked file operations on underlying
files. Operations on files with "fake" path must not generate fsnotify
events with path data, because those events have already been generated at
overlayfs layer and because the reported event->fd for fanotify marks on
underlying inode/filesystem will have the wrong path (the overlayfs path).
Link: https://lore.kernel.org/linux-fsdevel/20190423065024.12695-1-jencce.kernel@gmail.com/
Reported-by: Murphy Zhou <jencce.kernel@gmail.com>
Fixes: d1d04ef8572b ("ovl: stack file ops")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit acf3062a7e1ccf67c6f7e7c28671a6708fde63b0 upstream.
This nasty little syzbot repro:
https://syzkaller.appspot.com/x/repro.syz?x=12c7a94f400000
Creates overlay mounts where the same directory is both in upper and lower
layers. Simplified example:
mkdir foo work
mount -t overlay none foo -o"lowerdir=.,upperdir=foo,workdir=work"
The repro runs several threads in parallel that attempt to chdir into foo
and attempt to symlink/rename/exec/mkdir the file bar.
The repro hits a WARN_ON() I placed in ovl_instantiate(), which suggests
that an overlay inode already exists in cache and is hashed by the pointer
of the real upper dentry that ovl_create_real() has just created. At the
point of the WARN_ON(), for overlay dir inode lock is held and upper dir
inode lock, so at first, I did not see how this was possible.
On a closer look, I see that after ovl_create_real(), because of the
overlapping upper and lower layers, a lookup by another thread can find the
file foo/bar that was just created in upper layer, at overlay path
foo/foo/bar and hash the an overlay inode with the new real dentry as lower
dentry. This is possible because the overlay directory foo/foo is not
locked and the upper dentry foo/bar is in dcache, so ovl_lookup() can find
it without taking upper dir inode shared lock.
Overlapping layers is considered a wrong setup which would result in
unexpected behavior, but it shouldn't crash the kernel and it shouldn't
trigger WARN_ON() either, so relax this WARN_ON() and leave a pr_warn()
instead to cover all cases of failure to get an overlay inode.
The error returned from failure to insert new inode to cache with
inode_insert5() was changed to -EEXIST, to distinguish from the error
-ENOMEM returned on failure to get/allocate inode with iget5_locked().
Reported-by: syzbot+9c69c282adc4edd2b540@syzkaller.appspotmail.com
Fixes: 01b39dcc9568 ("ovl: use inode_insert5() to hash a newly...")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 3428030da004a1128cbdcf93dc03e16f184d845b upstream.
Generalize the helper ovl_open_maybe_copy_up() and use it to copy up file
with data before FS_IOC_SETFLAGS ioctl.
The FS_IOC_SETFLAGS ioctl is a bit of an odd ball in vfs, which probably
caused the confusion. File may be open O_RDONLY, but ioctl modifies the
file. VFS does not call mnt_want_write_file() nor lock inode mutex, but
fs-specific code for FS_IOC_SETFLAGS does. So ovl_ioctl() calls
mnt_want_write_file() for the overlay file, and fs-specific code calls
mnt_want_write_file() for upper fs file, but there was no call for
ovl_want_write() for copy up duration which prevents overlayfs from copying
up on a frozen upper fs.
Fixes: dab5ca8fd9dd ("ovl: add lsattr/chattr support")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 993a0b2aec52754f0897b1dab4c453be8217cae5 upstream.
If a file has been copied up metadata only, and later data is copied up,
upper loses any security.capability xattr it has (underlying filesystem
clears it as upon file write).
From a user's point of view, this is just a file copy-up and that should
not result in losing security.capability xattr. Hence, before data copy
up, save security.capability xattr (if any) and restore it on upper after
data copy up is complete.
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Fixes: 0c2888749363 ("ovl: A new xattr OVL_XATTR_METACOPY for file on upper")
Cc: <stable@vger.kernel.org> # v4.19+
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5f32879ea35523b9842bdbdc0065e13635caada2 upstream.
If a file with capability set (and hence security.capability xattr) is
written kernel clears security.capability xattr. For overlay, during file
copy up if xattrs are copied up first and then data is, copied up. This
means data copy up will result in clearing of security.capability xattr
file on lower has. And this can result into surprises. If a lower file has
CAP_SETUID, then it should not be cleared over copy up (if nothing was
actually written to file).
This also creates problems with chown logic where it first copies up file
and then tries to clear setuid bit. But by that time security.capability
xattr is already gone (due to data copy up), and caller gets -ENODATA.
This has been reported by Giuseppe here.
https://github.com/containers/libpod/issues/2015#issuecomment-447824842
Fix this by copying up data first and then metadta. This is a regression
which has been introduced by my commit as part of metadata only copy up
patches.
TODO: There will be some corner cases where a file is copied up metadata
only and later data copy up happens and that will clear security.capability
xattr. Something needs to be done about that too.
Fixes: bd64e57586d3 ("ovl: During copy up, first copy up metadata and then data")
Cc: <stable@vger.kernel.org> # v4.19+
Reported-by: Giuseppe Scrivano <gscrivan@redhat.com>
Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 91ff20f34e94424e586f57f4f593beae16504f86 upstream.
Theodore Ts'o reported a v4.19 regression with docker-dropbox:
https://marc.info/?l=linux-fsdevel&m=154070089431116&w=2
"I was rebuilding my dropbox Docker container, and it failed in 4.19
with the following error:
...
dpkg: error: error creating new backup file \
'/var/lib/dpkg/status-old': Invalid cross-device link"
The problem did not reproduce with metacopy feature disabled.
The error was caused by insufficient credentials to set
"trusted.overlay.redirect" xattr on link of a metacopy file.
Reproducer:
echo Y > /sys/module/overlay/parameters/redirect_dir
echo Y > /sys/module/overlay/parameters/metacopy
cd /tmp
mkdir l u w m
chmod 777 l u
touch l/foo
ln l/foo l/link
chmod 666 l/foo
mount -t overlay none -olowerdir=l,upperdir=u,workdir=w m
su fsgqa
ln m/foo m/bar
[ 21.455823] overlayfs: failed to set redirect (-1)
ln: failed to create hard link 'm/bar' => 'm/foo':\
Invalid cross-device link
Reported-by: Theodore Y. Ts'o <tytso@mit.edu>
Reported-by: Maciej Zięba <maciekz82@gmail.com>
Fixes: 4120fe64dce4 ("ovl: Set redirect on upper inode when it is linked")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 155b8a0492a90a4c6e22f046a3568b92a6bc48da upstream.
When decoding a lower file handle, we first call ovl_check_origin_fh()
with connected=false to get any real lower dentry for overlay inode
cache lookup.
If the real dentry is a disconnected dir dentry, ovl_check_origin_fh()
is called again with connected=true to get a connected real dentry
and find the lower layer the real dentry belongs to.
If the first call returned a connected real dentry, we use it to
lookup an overlay connected dentry, but the first ovl_check_origin_fh()
call with connected=false did not check that the found dentry is under
the root of the layer (see ovl_acceptable()), it only checked that
the found dentry super block matches the uuid of the lower file handle.
In case there are multiple lower layers on the same fs and the found
dentry is not from the top most lower layer, using the layer index
returned from the first ovl_check_origin_fh() is wrong and we end
up failing to decode the file handle.
Fix this by always calling ovl_check_origin_fh() with connected=true
if we got a directory dentry in the first call.
Fixes: 8b58924ad55c ("ovl: lookup in inode cache first when decoding...")
Cc: <stable@vger.kernel.org> # v4.17
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit d47748e5ae5af6572e520cc9767bbe70c22ea498 upstream.
Current behavior is to automatically disable metacopy if redirect_dir is
not enabled and proceed with the mount.
If "metacopy=on" mount option was given, then this behavior can confuse the
user: no mount failure, yet metacopy is disabled.
This patch makes metacopy=on imply redirect_dir=on.
The converse is also true: turning off full redirect with redirect_dir=
{off|follow|nofollow} will disable metacopy.
If both metacopy=on and redirect_dir={off|follow|nofollow} is specified,
then mount will fail, since there's no way to correctly resolve the
conflict.
Reported-by: Daniel Walsh <dwalsh@redhat.com>
Fixes: d5791044d2e5 ("ovl: Provide a mount option metacopy=on/off...")
Cc: <stable@vger.kernel.org> # v4.19
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5e1275808630ea3b2c97c776f40e475017535f72 upstream.
Kaixuxia repors that it's possible to crash overlayfs by removing the
whiteout on the upper layer before creating a directory over it. This is a
reproducer:
mkdir lower upper work merge
touch lower/file
mount -t overlay overlay -olowerdir=lower,upperdir=upper,workdir=work merge
rm merge/file
ls -al merge/file
rm upper/file
ls -al merge/
mkdir merge/file
Before commencing with a vfs_rename(..., RENAME_EXCHANGE) verify that the
lookup of "upper" is positive and is a whiteout, and return ESTALE
otherwise.
Reported by: kaixuxia <xiakaixu1987@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: e9be9d5e76e3 ("overlay filesystem")
Cc: <stable@vger.kernel.org> # v3.18
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 6cd078702f2f33cb6b19a682de3e9184112f1a46 upstream.
linking a non-copied-up file into a non-copied-up parent results in a
nested call to mutex_lock_interruptible(&oi->lock). Fix this by copying up
target parent before ovl_nlink_start(), same as done in ovl_rename().
~/unionmount-testsuite$ ./run --ov -s
~/unionmount-testsuite$ ln /mnt/a/foo100 /mnt/a/dir100/
WARNING: possible recursive locking detected
--------------------------------------------
ln/1545 is trying to acquire lock:
00000000bcce7c4c (&ovl_i_lock_key[depth]){+.+.}, at:
ovl_copy_up_start+0x28/0x7d
but task is already holding lock:
0000000026d73d5b (&ovl_i_lock_key[depth]){+.+.}, at:
ovl_nlink_start+0x3c/0xc1
[SzM: this seems to be a false positive, but doing the copy-up first is
harmless and removes the lockdep splat]
Reported-by: syzbot+3ef5c0d1a5cb0b21e6be@syzkaller.appspotmail.com
Fixes: 5f8415d6b87e ("ovl: persistent overlay inode nlink for...")
Cc: <stable@vger.kernel.org> # v4.13
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Format has a typo: it was meant to be "%.*s", not "%*s". But at some point
callers grew nonprintable values as well, so use "%*pE" instead with a
maximized length.
Reported-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 3a1e819b4e80 ("ovl: store file handle of lower inode on copy up")
Cc: <stable@vger.kernel.org> # v4.12
Fixes the following sparse warning:
fs/overlayfs/inode.c:507:39: warning:
symbol 'ovl_aops' was not declared. Should it be static?
Fixes: 5b910bd615ba ("ovl: fix GPF in swapfile_activate of file from overlayfs over xfs")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Commit 031a072a0b8a ("vfs: call vfs_clone_file_range() under freeze
protection") created a wrapper do_clone_file_range() around
vfs_clone_file_range() moving the freeze protection to former, so
overlayfs could call the latter.
The more common vfs practice is to call do_xxx helpers from vfs_xxx
helpers, where freeze protecction is taken in the vfs_xxx helper, so
this anomality could be a source of confusion.
It seems that commit 8ede205541ff ("ovl: add reflink/copyfile/dedup
support") may have fallen a victim to this confusion -
ovl_clone_file_range() calls the vfs_clone_file_range() helper in the
hope of getting freeze protection on upper fs, but in fact results in
overlayfs allowing to bypass upper fs freeze protection.
Swap the names of the two helpers to conform to common vfs practice
and call the correct helpers from overlayfs and nfsd.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested by doing clone on overlayfs while upper xfs+reflink is frozen:
xfs_io -f /ovl/y
fsfreeze -f /xfs
xfs_io> reflink /ovl/x
Before the fix xfs_io enters xfs_reflink_remap_range() and blocks
in xfs_trans_alloc(). After the fix, xfs_io blocks outside xfs code
in ovl_clone_file_range().
Fixes: 8ede205541ff ("ovl: add reflink/copyfile/dedup support")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Tested by re-writing to an open overlayfs file while upper ext4 is frozen:
xfs_io -f /ovl/x
xfs_io> pwrite 0 4096
fsfreeze -f /ext4
xfs_io> pwrite 0 4096
WARNING: CPU: 0 PID: 1492 at fs/ext4/ext4_jbd2.c:53 \
ext4_journal_check_start+0x48/0x82
After the fix, the second write blocks in ovl_write_iter() and avoids
hitting WARN_ON(sb->s_writers.frozen == SB_FREEZE_COMPLETE) in
ext4_journal_check_start().
Fixes: 2a92e07edc5e ("ovl: add ovl_write_iter()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
The memory leak was detected by kmemleak when running xfstests
overlay/051,053
Fixes: caf70cb2ba5d ("ovl: cleanup orphan index entries")
Cc: <stable@vger.kernel.org> # v4.13
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
ovl_free_fs() dereferences ofs->workbasedir and ofs->upper_mnt in cases when
those might not have been initialized yet.
Fix the initialization order for these fields.
Reported-by: syzbot+c75f181dc8429d2eb887@syzkaller.appspotmail.com
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Cc: <stable@vger.kernel.org> # v4.15
Fixes: 95e6d4177cb7 ("ovl: grab reference to workbasedir early")
Fixes: a9075cdb467d ("ovl: factor out ovl_free_fs() helper")
