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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull overlayfs updates from Christian Brauner:
"This lets the merged overlayfs mount itself be idmapped through
mount_setattr(MOUNT_ATTR_IDMAP), in addition to the already supported
idmapped lower and upper layers. The same overlay tree can then be
exposed under a different ownership view.
Overlayfs already normalizes every underlying id through the relevant
layer idmap when ovl_copyattr() copies attributes into the overlay
inode. So the overlay inode's i_uid and i_gid are overlay-final ids.
The overlay mount idmap composes on top of that and is applied at the
overlay-inode boundary only while the underlying layers keep being
accessed with the mounter's credentials through their own (possibly
idmapped) mounts.
So this only changes how the caller sees the overlay inode and never
widens the mounter's access to the layers. The second,
mounter-credential check in ovl_permission() against the real inode
stays on the layer idmap.
Most paths need no change because the VFS applies the mount idmap to
the overlay inode before overlayfs runs or after it returns at the
syscall boundary. Overlayfs only has to change where it bypasses the
generic path.
This also included is a fix for a double end_creating() on the
overlayfs casefold-mismatch path"
* tag 'vfs-7.3-rc1.ovl' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
ovl: fix double end_creating() on the casefold-mismatch path
ovl: document security.capability idmapping on the xattr forward paths
selftests/filesystems/overlayfs: test idmapped overlay mounts
selftests/filesystems/overlayfs: fix set_layers_via_fds link error
docs: document idmapped overlay mounts
ovl: allow idmapping overlay mounts
ovl: handle idmapped mounts in ovl_set_acl()
ovl: handle idmapped mounts in ovl_getattr()
ovl: handle idmapped mounts in ovl_setattr()
ovl: handle idmapped mounts in ovl_permission()
ovl: handle idmapped mounts in ovl_create_object() and ovl_tmpfile()
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Forgot to update the comment when we changed the locking order.
Fixes: 162d06444070c ("ovl: reorder ovl_want_write() after ovl_inode_lock()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20260609184656.1916631-1-amir73il@gmail.com
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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The two checks ovl_set_acl() performs on the overlay inode itself -
inode_owner_or_capable() and the setgid-stripping test - were done with
&nop_mnt_idmap. On an idmapped overlay mount this compares the overlay
inode's id space directly against the caller's: it denies the rightful
owner (as seen through the mount idmap) the right to set an ACL, and
evaluates the setgid-drop decision in the wrong id space, which can
mis-set the mode on the upper inode.
Use the struct mnt_idmap passed in by the VFS for both. Fold the
open-coded "caller not in group and not CAP_FSETID privileged" test
into in_group_or_capable() with i_gid_into_vfsgid(), the same
idmap-aware helpers used by setattr_should_drop_sgid().
The subsequent internal forced setgid-kill via ovl_setattr() stays on
&nop_mnt_idmap: it carries only ATTR_KILL_SGID with no uid/gid to
translate and is overlayfs' own mode change, not a user-driven
operation through the mount.
No functional change until FS_ALLOW_IDMAP is set on ovl_fs_type.
Link: https://patch.msgid.link/20260615-work-idmapped-overlayfs-v1-5-7381632aa402@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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ovl_getattr() fetches attributes from the real (upper or lower) path
via vfs_getattr(), so the returned stat->uid/stat->gid are already
mapped through the real layer idmap but not through the overlay mount
idmap. Unlike the generic path, the VFS does not re-apply the
accessing mount's idmap after ->getattr returns - generic_fillattr()
does it, but overlayfs bypasses it - so overlayfs has to do it itself.
Map stat->uid/stat->gid through the overlay mount idmap before
returning, mirroring generic_fillattr(). The owner reported through an
idmapped overlay mount is thus the overlay-final id translated by the
mount idmap.
No functional change until FS_ALLOW_IDMAP is set on ovl_fs_type; until
then make_vfsuid()/make_vfsgid() are the identity for &nop_mnt_idmap.
Link: https://patch.msgid.link/20260615-work-idmapped-overlayfs-v1-4-7381632aa402@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Pass the mount's struct mnt_idmap to setattr_prepare() so that the
permission checks for a chown/chmod performed through an idmapped
overlay mount are evaluated in the mount's id space.
The ownership requested in @attr is expressed relative to the overlay
mount idmap. Before forwarding the change to the upper layer via
ovl_do_notify_change() - whose notify_change() applies the upper layer
idmap in turn - rebase ia_vfsuid/ia_vfsgid into the overlay's own id
space, i.e. the same space as the overlay inode's i_{u,g}id established
by ovl_copyattr(). Without this rebase the upper layer would interpret
the caller's mount-relative id as an upper-relative one and store the
wrong owner on disk, or reject it with -EOVERFLOW.
from_vfsuid() returns INVALID_UID for an id that the overlay mount
idmap does not map; that invalid id is carried faithfully into the
forwarded iattr and rejected by the upper notify_change() via
vfsuid_has_fsmapping(), so no bogus owner can be written.
No functional change until FS_ALLOW_IDMAP is set on ovl_fs_type; until
then the overlay mount idmap is &nop_mnt_idmap and from_vfsuid() is the
identity.
Link: https://patch.msgid.link/20260615-work-idmapped-overlayfs-v1-3-7381632aa402@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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When the overlay mount is idmapped, the permission check on the overlay
inode must account for the mount's idmapping. Use the struct mnt_idmap
passed in by the VFS instead of the hardcoded &nop_mnt_idmap when
checking the overlay inode against the caller's credentials.
The second check, which verifies that the mounter may access the
underlying real inode, continues to use the real layer's idmap
mnt_idmap(realpath.mnt) under the mounter's credentials and is
deliberately left unchanged. The overlay mount idmap only affects how
the caller views the overlay inode, not the mounter's access to the
layers, so it cannot widen access to the real files.
No functional change until FS_ALLOW_IDMAP is set on ovl_fs_type; until
then the overlay mount idmap is always &nop_mnt_idmap.
Link: https://patch.msgid.link/20260615-work-idmapped-overlayfs-v1-2-7381632aa402@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>
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Currently file_update_time_flags unconditionally returns -EAGAIN if any
timestamp needs to be updated and IOCB_NOWAIT is passed. This makes
non-blocking direct writes impossible on file systems with granular
enough timestamps.
Pass IOCB_NOWAIT to ->update_time and return -EAGAIN if it could block.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260108141934.2052404-9-hch@lst.de
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Pass the type of update (atime vs c/mtime plus version) as an enum
instead of a set of flags that caused all kinds of confusion.
Because inode_update_timestamps now can't return a modified version
of those flags, return the I_DIRTY_* flags needed to persist the
update, which is what the main caller in generic_update_time wants
anyway, and which is suitable for the other callers that only want
to know if an update happened.
The whole update_time path keeps the flags argument, which will be used
to support non-blocking updates soon even if it is unused, and (the
slightly renamed) inode_update_time also gains the possibility to return
a negative errno to support this.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20260108141934.2052404-6-hch@lst.de
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull overlayfs cred guard conversion from Christian Brauner:
"This converts all of overlayfs to use credential guards, eliminating
manual credential management throughout the filesystem.
Credential guard conversion:
- Convert all of overlayfs to use credential guards, replacing the
manual ovl_override_creds()/ovl_revert_creds() pattern with scoped
guards.
This makes credential handling visually explicit and eliminates a
class of potential bugs from mismatched override/revert calls.
(1) Basic credential guard (with_ovl_creds)
(2) Creator credential guard (ovl_override_creator_creds):
Introduced a specialized guard for file creation operations
that handles the two-phase credential override (mounter
credentials, then fs{g,u}id override). The new pattern is much
clearer:
with_ovl_creds(dentry->d_sb) {
scoped_class(prepare_creds_ovl, cred, dentry, inode, mode) {
if (IS_ERR(cred))
return PTR_ERR(cred);
/* creation operations */
}
}
(3) Copy-up credential guard (ovl_cu_creds):
Introduced a specialized guard for copy-up operations,
simplifying the previous struct ovl_cu_creds helper and
associated functions.
Ported ovl_copy_up_workdir() and ovl_copy_up_tmpfile() to this
pattern.
Cleanups:
- Remove ovl_revert_creds() after all callers converted to guards
- Remove struct ovl_cu_creds and associated functions
- Drop ovl_setup_cred_for_create() after conversion
- Refactor ovl_fill_super(), ovl_lookup(), ovl_iterate(),
ovl_rename() for cleaner credential guard scope
- Introduce struct ovl_renamedata to simplify rename handling
- Don't override credentials for ovl_check_whiteouts() (unnecessary)
- Remove unneeded semicolon"
* tag 'vfs-6.19-rc1.ovl' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (54 commits)
ovl: remove unneeded semicolon
ovl: remove struct ovl_cu_creds and associated functions
ovl: port ovl_copy_up_tmpfile() to cred guard
ovl: mark *_cu_creds() as unused temporarily
ovl: port ovl_copy_up_workdir() to cred guard
ovl: add copy up credential guard
ovl: drop ovl_setup_cred_for_create()
ovl: port ovl_create_or_link() to new ovl_override_creator_creds cleanup guard
ovl: mark ovl_setup_cred_for_create() as unused temporarily
ovl: reflow ovl_create_or_link()
ovl: port ovl_create_tmpfile() to new ovl_override_creator_creds cleanup guard
ovl: add ovl_override_creator_creds cred guard
ovl: remove ovl_revert_creds()
ovl: port ovl_fill_super() to cred guard
ovl: refactor ovl_fill_super()
ovl: port ovl_lower_positive() to cred guard
ovl: port ovl_lookup() to cred guard
ovl: refactor ovl_lookup()
ovl: port ovl_copyfile() to cred guard
ovl: port ovl_rename() to cred guard
...
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git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs inode updates from Christian Brauner:
"Features:
- Hide inode->i_state behind accessors. Open-coded accesses prevent
asserting they are done correctly. One obvious aspect is locking,
but significantly more can be checked. For example it can be
detected when the code is clearing flags which are already missing,
or is setting flags when it is illegal (e.g., I_FREEING when
->i_count > 0)
- Provide accessors for ->i_state, converts all filesystems using
coccinelle and manual conversions (btrfs, ceph, smb, f2fs, gfs2,
overlayfs, nilfs2, xfs), and makes plain ->i_state access fail to
compile
- Rework I_NEW handling to operate without fences, simplifying the
code after the accessor infrastructure is in place
Cleanups:
- Move wait_on_inode() from writeback.h to fs.h
- Spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
for clarity
- Cosmetic fixes to LRU handling
- Push list presence check into inode_io_list_del()
- Touch up predicts in __d_lookup_rcu()
- ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
- Assert on ->i_count in iput_final()
- Assert ->i_lock held in __iget()
Fixes:
- Add missing fences to I_NEW handling"
* tag 'vfs-6.19-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (22 commits)
dcache: touch up predicts in __d_lookup_rcu()
fs: push list presence check into inode_io_list_del()
fs: cosmetic fixes to lru handling
fs: rework I_NEW handling to operate without fences
fs: make plain ->i_state access fail to compile
xfs: use the new ->i_state accessors
nilfs2: use the new ->i_state accessors
overlayfs: use the new ->i_state accessors
gfs2: use the new ->i_state accessors
f2fs: use the new ->i_state accessors
smb: use the new ->i_state accessors
ceph: use the new ->i_state accessors
btrfs: use the new ->i_state accessors
Manual conversion to use ->i_state accessors of all places not covered by coccinelle
Coccinelle-based conversion to use ->i_state accessors
fs: provide accessors for ->i_state
fs: spell out fenced ->i_state accesses with explicit smp_wmb/smp_rmb
fs: move wait_on_inode() from writeback.h to fs.h
fs: add missing fences to I_NEW handling
ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage
...
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-21-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-20-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-19-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-18-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-17-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-16-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-15-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-14-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the scoped ovl cred guard.
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-13-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Change generated with coccinelle and fixed up by hand as appropriate.
Signed-off-by: Mateusz Guzik <mjguzik@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This reverts commit 474b155adf3927d2c944423045757b54aa1ca4de.
This patch caused regression in ioctl_setflags(). Underlying filesystems
use EOPNOTSUPP to indicate that flag is not supported. This error is
also gets converted in ioctl_setflags(). Therefore, for unsupported
flags error changed from EOPNOSUPP to ENOIOCTLCMD.
Link: https://lore.kernel.org/linux-xfs/a622643f-1585-40b0-9441-cf7ece176e83@kernel.org/
Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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To keep ovl's inodes consistent with their real inodes, create a new
mask for inode file attributes that needs to be copied. Add the
S_CASEFOLD flag as part of the flags that need to be copied along with
the other file attributes.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: André Almeida <andrealmeid@igalia.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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Now that we expose struct file_attr as our uapi struct rename all the
internal struct to struct file_kattr to clearly communicate that it is a
kernel internal struct. This is similar to struct mount_{k}attr and
others.
Link: https://lore.kernel.org/20250703-restlaufzeit-baurecht-9ed44552b481@brauner
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Future patches will add new syscalls which use these functions. As
this interface won't be used for ioctls only, the EOPNOSUPP is more
appropriate return code.
This patch converts return code from ENOIOCTLCMD to EOPNOSUPP for
vfs_fileattr_get and vfs_fileattr_set. To save old behavior translate
EOPNOSUPP back for current users - overlayfs, encryptfs and fs/ioctl.c.
Signed-off-by: Andrey Albershteyn <aalbersh@kernel.org>
Link: https://lore.kernel.org/20250630-xattrat-syscall-v6-4-c4e3bc35227b@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs updates from Amir Goldstein:
- Fix a syzbot reported NULL pointer deref with bfs lower layers
- Fix a copy up failure of large file from lower fuse fs
- Followup cleanup of backing_file API from Miklos
- Introduction and use of revert/override_creds_light() helpers, that
were suggested by Christian as a mitigation to cache line bouncing
and false sharing of fields in overlayfs creator_cred long lived
struct cred copy.
- Store up to two backing file references (upper and lower) in an
ovl_file container instead of storing a single backing file in
file->private_data.
This is used to avoid the practice of opening a short lived backing
file for the duration of some file operations and to avoid the
specialized use of FDPUT_FPUT in such occasions, that was getting in
the way of Al's fd_file() conversions.
* tag 'ovl-update-6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: Filter invalid inodes with missing lookup function
ovl: convert ovl_real_fdget() callers to ovl_real_file()
ovl: convert ovl_real_fdget_path() callers to ovl_real_file_path()
ovl: store upper real file in ovl_file struct
ovl: allocate a container struct ovl_file for ovl private context
ovl: do not open non-data lower file for fsync
ovl: Optimize override/revert creds
ovl: pass an explicit reference of creators creds to callers
ovl: use wrapper ovl_revert_creds()
fs/backing-file: Convert to revert/override_creds_light()
cred: Add a light version of override/revert_creds()
backing-file: clean up the API
ovl: properly handle large files in ovl_security_fileattr
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Commit 8a924db2d7b5 ("fs: Pass AT_GETATTR_NOSEC flag to getattr interface
function")' introduced the AT_GETATTR_NOSEC flag to ensure that the
call paths only call vfs_getattr_nosec if it is set instead of vfs_getattr.
Now, simplify the getattr interface functions of filesystems where the flag
AT_GETATTR_NOSEC is checked.
There is only a single caller of inode_operations getattr function and it
is located in fs/stat.c in vfs_getattr_nosec. The caller there is the only
one from which the AT_GETATTR_NOSEC flag is passed from.
Two filesystems are checking this flag in .getattr and the flag is always
passed to them unconditionally from only vfs_getattr_nosec:
- ecryptfs: Simplify by always calling vfs_getattr_nosec in
ecryptfs_getattr. From there the flag is passed to no other
function and this function is not called otherwise.
- overlayfs: Simplify by always calling vfs_getattr_nosec in
ovl_getattr. From there the flag is passed to no other
function and this function is not called otherwise.
The query_flags in vfs_getattr_nosec will mask-out AT_GETATTR_NOSEC from
any caller using AT_STATX_SYNC_TYPE as mask so that the flag is not
important inside this function. Also, since no filesystem is checking the
flag anymore, remove the flag entirely now, including the BUG_ON check that
never triggered.
The net change of the changes here combined with the original commit is
that ecryptfs and overlayfs do not call vfs_getattr but only
vfs_getattr_nosec.
Fixes: 8a924db2d7b5 ("fs: Pass AT_GETATTR_NOSEC flag to getattr interface function")
Reported-by: Al Viro <viro@zeniv.linux.org.uk>
Closes: https://lore.kernel.org/linux-fsdevel/20241101011724.GN1350452@ZenIV/T/#u
Cc: Tyler Hicks <code@tyhicks.com>
Cc: ecryptfs@vger.kernel.org
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: linux-unionfs@vger.kernel.org
Cc: Christian Brauner <brauner@kernel.org>
Cc: linux-fsdevel@vger.kernel.org
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Introduce ovl_revert_creds() wrapper of revert_creds() to
match callers of ovl_override_creds().
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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dentry_open in ovl_security_fileattr fails for any file
larger than 2GB if open method of the underlying filesystem
calls generic_file_open (e.g. fusefs).
The issue can be reproduce using the following script:
(passthrough_ll is an example app from libfuse).
$ D=/opt/test/mnt
$ mkdir -p ${D}/{source,base,top/uppr,top/work,ovlfs}
$ dd if=/dev/zero of=${D}/source/zero.bin bs=1G count=2
$ passthrough_ll -o source=${D}/source ${D}/base
$ mount -t overlay overlay \
-olowerdir=${D}/base,upperdir=${D}/top/uppr,workdir=${D}/top/work \
${D}/ovlfs
$ chmod 0777 ${D}/mnt/ovlfs/zero.bin
Running this script results in "Value too large for defined data type"
error message from chmod.
Signed-off-by: Oleksandr Tymoshenko <ovt@google.com>
Fixes: 72db82115d2b ("ovl: copy up sync/noatime fileattr flags")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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Remove duplicate included header file linux/posix_acl.h
Signed-off-by: Thorsten Blum <thorsten.blum@toblux.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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When vfs_getattr_nosec() calls a filesystem's getattr interface function
then the 'nosec' should propagate into this function so that
vfs_getattr_nosec() can again be called from the filesystem's gettattr
rather than vfs_getattr(). The latter would add unnecessary security
checks that the initial vfs_getattr_nosec() call wanted to avoid.
Therefore, introduce the getattr flag GETATTR_NOSEC and allow to pass
with the new getattr_flags parameter to the getattr interface function.
In overlayfs and ecryptfs use this flag to determine which one of the
two functions to call.
In a recent code change introduced to IMA vfs_getattr_nosec() ended up
calling vfs_getattr() in overlayfs, which in turn called
security_inode_getattr() on an exiting process that did not have
current->fs set anymore, which then caused a kernel NULL pointer
dereference. With this change the call to security_inode_getattr() can
be avoided, thus avoiding the NULL pointer dereference.
Reported-by: <syzbot+a67fc5321ffb4b311c98@syzkaller.appspotmail.com>
Fixes: db1d1e8b9867 ("IMA: use vfs_getattr_nosec to get the i_version")
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Amir Goldstein <amir73il@gmail.com>
Cc: Tyler Hicks <code@tyhicks.com>
Cc: Mimi Zohar <zohar@linux.ibm.com>
Suggested-by: Christian Brauner <brauner@kernel.org>
Co-developed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Link: https://lore.kernel.org/r/20231002125733.1251467-1-stefanb@linux.vnet.ibm.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This moves the code from super.c and inode.c, and makes ovl_xattr_get/set()
static.
This is in preparation for doing more work on xattrs support.
Signed-off-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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Make the locking order of ovl_inode_lock() strictly between the two
vfs stacked layers, i.e.:
- ovl vfs locks: sb_writers, inode_lock, ...
- ovl_inode_lock
- upper vfs locks: sb_writers, inode_lock, ...
To that effect, move ovl_want_write() into the helpers ovl_nlink_start()
and ovl_copy_up_start which currently take the ovl_inode_lock() after
ovl_want_write().
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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Convert to using the new inode timestamp accessor functions.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://lore.kernel.org/r/20231004185347.80880-58-jlayton@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
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git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs
Pull overlayfs updates from Amir Goldstein:
- add verification feature needed by composefs (Alexander Larsson)
- improve integration of overlayfs and fanotify (Amir Goldstein)
- fortify some overlayfs code (Andrea Righi)
* tag 'ovl-update-6.6' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: validate superblock in OVL_FS()
ovl: make consistent use of OVL_FS()
ovl: Kconfig: introduce CONFIG_OVERLAY_FS_DEBUG
ovl: auto generate uuid for new overlay filesystems
ovl: store persistent uuid/fsid with uuid=on
ovl: add support for unique fsid per instance
ovl: support encoding non-decodable file handles
ovl: Handle verity during copy-up
ovl: Validate verity xattr when resolving lowerdata
ovl: Add versioned header for overlay.metacopy xattr
ovl: Add framework for verity support
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Always use OVL_FS() to retrieve the corresponding struct ovl_fs from a
struct super_block.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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When all layers support file handles, we support encoding non-decodable
file handles (a.k.a. fid) even with nfs_export=off.
When file handles do not need to be decoded, we do not need to copy up
redirected lower directories on encode, and we encode also non-indexed
upper with lower file handle, so fid will not change on copy up.
This enables reporting fanotify events with file handles on overlayfs
with default config/mount options.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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Now that all of the update_time operations are prepared for it, we can
drop the timespec64 argument from the update_time operation. Do that and
remove it from some associated functions like inode_update_time and
inode_needs_update_time.
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-Id: <20230807-mgctime-v7-8-d1dec143a704@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Internal ovl methods should use ovl_fs and not sb as much as
possible.
Use a constant_table to translate from enum xino mode to string
in preperation for new mount api option parsing.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
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Make the code handle the case of numlower > 1 and missing lowerdata
dentry gracefully.
Missing lowerdata dentry is an indication for lazy lookup of lowerdata
and in that case the lowerdata_redirect path is stored in ovl_inode.
Following commits will defer lookup and perform the lazy lookup on
access.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Prepare to allow ovl_lookup() to leave the last entry in a non-dir
lowerstack empty to signify lazy lowerdata lookup.
In this case, ovl_lookup() stores the redirect path from metacopy to
lowerdata in ovl_inode, which is going to be used later to perform the
lazy lowerdata lookup.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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The ovl_inode contains a copy of lowerdata in lowerstack[], so the
lowerdata inode member can be removed.
Use accessors ovl_lowerdata*() to get the lowerdata whereever the member
was accessed directly.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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The ovl_inode contains a copy of lowerpath in lowerstack[0], so the
lowerpath member can be removed.
Use accessor ovl_lowerpath() to get the lowerpath whereever the member
was accessed directly.
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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The lower stacks of all the ovl inode aliases should be identical
and there is redundant information in ovl_entry and ovl_inode.
Move lowerstack into ovl_inode and keep only the OVL_E_FLAGS
per overlay dentry.
Following patches will deduplicate redundant ovl_inode fields.
Note that for pure upper and negative dentries, OVL_E(dentry) may be
NULL now, so it is imporatnt to use the ovl_numlower() accessor.
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Following process:
P1 P2
path_openat
link_path_walk
may_lookup
inode_permission(rcu)
ovl_permission
acl_permission_check
check_acl
get_cached_acl_rcu
ovl_get_inode_acl
realinode = ovl_inode_real(ovl_inode)
drop_cache
__dentry_kill(ovl_dentry)
iput(ovl_inode)
ovl_destroy_inode(ovl_inode)
dput(oi->__upperdentry)
dentry_kill(upperdentry)
dentry_unlink_inode
upperdentry->d_inode = NULL
ovl_inode_upper
upperdentry = ovl_i_dentry_upper(ovl_inode)
d_inode(upperdentry) // returns NULL
IS_POSIXACL(realinode) // NULL pointer dereference
, will trigger an null pointer dereference at realinode:
[ 205.472797] BUG: kernel NULL pointer dereference, address:
0000000000000028
[ 205.476701] CPU: 2 PID: 2713 Comm: ls Not tainted
6.3.0-12064-g2edfa098e750-dirty #1216
[ 205.478754] RIP: 0010:do_ovl_get_acl+0x5d/0x300
[ 205.489584] Call Trace:
[ 205.489812] <TASK>
[ 205.490014] ovl_get_inode_acl+0x26/0x30
[ 205.490466] get_cached_acl_rcu+0x61/0xa0
[ 205.490908] generic_permission+0x1bf/0x4e0
[ 205.491447] ovl_permission+0x79/0x1b0
[ 205.491917] inode_permission+0x15e/0x2c0
[ 205.492425] link_path_walk+0x115/0x550
[ 205.493311] path_lookupat.isra.0+0xb2/0x200
[ 205.493803] filename_lookup+0xda/0x240
[ 205.495747] vfs_fstatat+0x7b/0xb0
Fetch a reproducer in [Link].
Use the helper ovl_i_path_realinode() to get realinode and then do
non-nullptr checking.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217404
Fixes: 332f606b32b6 ("ovl: enable RCU'd ->get_acl()")
Cc: <stable@vger.kernel.org> # v5.15
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Suggested-by: Christian Brauner <brauner@kernel.org>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Following process:
P1 P2
path_lookupat
link_path_walk
inode_permission
ovl_permission
ovl_i_path_real(inode, &realpath)
path->dentry = ovl_i_dentry_upper(inode)
drop_cache
__dentry_kill(ovl_dentry)
iput(ovl_inode)
ovl_destroy_inode(ovl_inode)
dput(oi->__upperdentry)
dentry_kill(upperdentry)
dentry_unlink_inode
upperdentry->d_inode = NULL
realinode = d_inode(realpath.dentry) // return NULL
inode_permission(realinode)
inode->i_sb // NULL pointer dereference
, will trigger an null pointer dereference at realinode:
[ 335.664979] BUG: kernel NULL pointer dereference,
address: 0000000000000002
[ 335.668032] CPU: 0 PID: 2592 Comm: ls Not tainted 6.3.0
[ 335.669956] RIP: 0010:inode_permission+0x33/0x2c0
[ 335.678939] Call Trace:
[ 335.679165] <TASK>
[ 335.679371] ovl_permission+0xde/0x320
[ 335.679723] inode_permission+0x15e/0x2c0
[ 335.680090] link_path_walk+0x115/0x550
[ 335.680771] path_lookupat.isra.0+0xb2/0x200
[ 335.681170] filename_lookup+0xda/0x240
[ 335.681922] vfs_statx+0xa6/0x1f0
[ 335.682233] vfs_fstatat+0x7b/0xb0
Fetch a reproducer in [Link].
Use the helper ovl_i_path_realinode() to get realinode and then do
non-nullptr checking.
Link: https://bugzilla.kernel.org/show_bug.cgi?id=217405
Fixes: 4b7791b2e958 ("ovl: handle idmappings in ovl_permission()")
Cc: <stable@vger.kernel.org> # v5.19
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Suggested-by: Christian Brauner <brauner@kernel.org>
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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Convert to struct mnt_idmap.
Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.
Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.
Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.
Acked-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
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