1168 Commits

Author SHA1 Message Date
Christian Brauner
87c9e88ac4 ovl: pass original credentials, not mounter credentials during create
When creating new files the security layer expects the original
credentials to be passed.  When cleaning up the code this was accidently
changed to pass the mounter's credentials by relying on current->cred
which is already overriden at this point.  Pass the original credentials
directly.

Reported-by: Ondrej Mosnacek <omosnace@redhat.com>
Reported-by: Paul Moore <paul@paul-moore.com>
Fixes: e566bff963 ("ovl: port ovl_create_or_link() to new ovl_override_creator_creds")
Link: https://lore.kernel.org/CAFqZXNvL1ciLXMhHrnoyBmQu1PAApH41LkSWEhrcvzAAbFij8Q@mail.gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Tested-by: Ondrej Mosnacek <omosnace@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2025-12-05 16:16:20 -08:00
Linus Torvalds
4b6b432128 Merge tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse
Pull fuse updates from Miklos Szeredi:

 - Add mechanism for cleaning out unused, stale dentries; controlled via
   a module option (Luis Henriques)

 - Fix various bugs

 - Cleanups

* tag 'fuse-update-6.19' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse:
  fuse: Uninitialized variable in fuse_epoch_work()
  fuse: fix io-uring list corruption for terminated non-committed requests
  fuse: signal that a fuse inode should exhibit local fs behaviors
  fuse: Always flush the page cache before FOPEN_DIRECT_IO write
  fuse: Invalidate the page cache after FOPEN_DIRECT_IO write
  fuse: rename 'namelen' to 'namesize'
  fuse: use strscpy instead of strcpy
  fuse: refactor fuse_conn_put() to remove negative logic.
  fuse: new work queue to invalidate dentries from old epochs
  fuse: new work queue to periodically invalidate expired dentries
  dcache: export shrink_dentry_list() and add new helper d_dispose_if_unused()
  fuse: add WARN_ON and comment for RCU revalidate
  fuse: Fix whitespace for fuse_uring_args_to_ring() comment
  fuse: missing copy_finish in fuse-over-io-uring argument copies
  fuse: fix readahead reclaim deadlock
2025-12-05 15:25:13 -08:00
Linus Torvalds
d0deeb803c Merge tag 'vfs-6.19-rc1.ovl' of 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
  ...
2025-12-01 16:31:21 -08:00
Linus Torvalds
a8058f8442 Merge tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull directory locking updates from Christian Brauner:
 "This contains the work to add centralized APIs for directory locking
  operations.

  This series is part of a larger effort to change directory operation
  locking to allow multiple concurrent operations in a directory. The
  ultimate goal is to lock the target dentry(s) rather than the whole
  parent directory.

  To help with changing the locking protocol, this series centralizes
  locking and lookup in new helper functions. The helpers establish a
  pattern where it is the dentry that is being locked and unlocked
  (currently the lock is held on dentry->d_parent->d_inode, but that can
  change in the future).

  This also changes vfs_mkdir() to unlock the parent on failure, as well
  as dput()ing the dentry. This allows end_creating() to only require
  the target dentry (which may be IS_ERR() after vfs_mkdir()), not the
  parent"

* tag 'vfs-6.19-rc1.directory.locking' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  nfsd: fix end_creating() conversion
  VFS: introduce end_creating_keep()
  VFS: change vfs_mkdir() to unlock on failure.
  ecryptfs: use new start_creating/start_removing APIs
  Add start_renaming_two_dentries()
  VFS/ovl/smb: introduce start_renaming_dentry()
  VFS/nfsd/ovl: introduce start_renaming() and end_renaming()
  VFS: add start_creating_killable() and start_removing_killable()
  VFS: introduce start_removing_dentry()
  smb/server: use end_removing_noperm for for target of smb2_create_link()
  VFS: introduce start_creating_noperm() and start_removing_noperm()
  VFS/nfsd/cachefiles/ovl: introduce start_removing() and end_removing()
  VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating()
  VFS: tidy up do_unlinkat()
  VFS: introduce start_dirop() and end_dirop()
  debugfs: rename end_creating() to debugfs_end_creating()
2025-12-01 16:13:46 -08:00
Linus Torvalds
db74a7d02a Merge tag 'vfs-6.19-rc1.directory.delegations' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull directory delegations update from Christian Brauner:
 "This contains the work for recall-only directory delegations for
  knfsd.

  Add support for simple, recallable-only directory delegations. This
  was decided at the fall NFS Bakeathon where the NFS client and server
  maintainers discussed how to merge directory delegation support.

  The approach starts with recallable-only delegations for several reasons:

   1. RFC8881 has gaps that are being addressed in RFC8881bis. In
      particular, it requires directory position information for
      CB_NOTIFY callbacks, which is difficult to implement properly
      under Linux. The spec is being extended to allow that information
      to be omitted.

   2. Client-side support for CB_NOTIFY still lags. The client side
      involves heuristics about when to request a delegation.

   3. Early indication shows simple, recallable-only delegations can
      help performance. Anna Schumaker mentioned seeing a multi-minute
      speedup in xfstests runs with them enabled.

  With these changes, userspace can also request a read lease on a
  directory that will be recalled on conflicting accesses. This may be
  useful for applications like Samba. Users can disable leases
  altogether via the fs.leases-enable sysctl if needed.

  VFS changes:

   - Dedicated Type for Delegations

     Introduce struct delegated_inode to track inodes that may have
     delegations that need to be broken. This replaces the previous
     approach of passing raw inode pointers through the delegation
     breaking code paths, providing better type safety and clearer
     semantics for the delegation machinery.

   - Break parent directory delegations in open(..., O_CREAT) codepath

   - Allow mkdir to wait for delegation break on parent

   - Allow rmdir to wait for delegation break on parent

   - Add try_break_deleg calls for parents to vfs_link(), vfs_rename(),
     and vfs_unlink()

   - Make vfs_create(), vfs_mknod(), and vfs_symlink() break delegations
     on parent directory

   - Clean up argument list for vfs_create()

   - Expose delegation support to userland

  Filelock changes:

   - Make lease_alloc() take a flags argument

   - Rework the __break_lease API to use flags

   - Add struct delegated_inode

   - Push the S_ISREG check down to ->setlease handlers

   - Lift the ban on directory leases in generic_setlease

  NFSD changes:

   - Allow filecache to hold S_IFDIR files

   - Allow DELEGRETURN on directories

   - Wire up GET_DIR_DELEGATION handling

  Fixes:

   - Fix kernel-doc warnings in __fcntl_getlease

   - Add needed headers for new struct delegation definition"

* tag 'vfs-6.19-rc1.directory.delegations' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  vfs: add needed headers for new struct delegation definition
  filelock: __fcntl_getlease: fix kernel-doc warnings
  vfs: expose delegation support to userland
  nfsd: wire up GET_DIR_DELEGATION handling
  nfsd: allow DELEGRETURN on directories
  nfsd: allow filecache to hold S_IFDIR files
  filelock: lift the ban on directory leases in generic_setlease
  vfs: make vfs_symlink break delegations on parent dir
  vfs: make vfs_mknod break delegations on parent directory
  vfs: make vfs_create break delegations on parent directory
  vfs: clean up argument list for vfs_create()
  vfs: break parent dir delegations in open(..., O_CREAT) codepath
  vfs: allow rmdir to wait for delegation break on parent
  vfs: allow mkdir to wait for delegation break on parent
  vfs: add try_break_deleg calls for parents to vfs_{link,rename,unlink}
  filelock: push the S_ISREG check down to ->setlease handlers
  filelock: add struct delegated_inode
  filelock: rework the __break_lease API to use flags
  filelock: make lease_alloc() take a flags argument
2025-12-01 15:34:41 -08:00
Linus Torvalds
9368f0f941 Merge tag 'vfs-6.19-rc1.inode' of 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
  ...
2025-12-01 09:02:34 -08:00
Chen Ni
2579e21be5 ovl: remove unneeded semicolon
Remove unnecessary semicolons reported by Coccinelle/coccicheck and the
semantic patch at scripts/coccinelle/misc/semicolon.cocci.

Signed-off-by: Chen Ni <nichen@iscas.ac.cn>
Fixed: 7ab96df840 ("VFS/nfsd/cachefiles/ovl: add start_creating() and end_creating()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-28 11:05:52 +01:00
NeilBrown
e9c70084a6 ovl: fail ovl_lock_rename_workdir() if either target is unhashed
As well as checking that the parent hasn't changed after getting the
lock we need to check that the dentry hasn't been unhashed.
Otherwise we might try to rename something that has been removed.

Reported-by: syzbot+bfc9a0ccf0de47d04e8c@syzkaller.appspotmail.com
Fixes: d2c995581c ("ovl: Call ovl_create_temp() without lock held.")
Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/176429295510.634289.1552337113663461690@noble.neil.brown.name
Tested-by: syzbot+bfc9a0ccf0de47d04e8c@syzkaller.appspotmail.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-28 10:42:32 +01:00
Christian Brauner
2c42b6ce4a ovl: remove struct ovl_cu_creds and associated functions
Now that we have this all ported to a cred guard remove the struct and
the associated helpers.

Link: https://patch.msgid.link/20251114-work-ovl-cred-guard-copyup-v1-5-ea3fb15cf427@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:27 +01:00
Christian Brauner
72f098f0dd ovl: port ovl_copy_up_tmpfile() to cred guard
Remove the complicated struct ovl_cu_creds dance and use our new copy up
cred guard.

Link: https://patch.msgid.link/20251114-work-ovl-cred-guard-copyup-v1-4-ea3fb15cf427@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:27 +01:00
Christian Brauner
643b8a2c0a ovl: mark *_cu_creds() as unused temporarily
They will become unused in the next patch and we'll drop them after the
conversion is finished together with the struct. This keeps the changes
small and reviewable.

Link: https://patch.msgid.link/20251114-work-ovl-cred-guard-copyup-v1-3-ea3fb15cf427@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:27 +01:00
Christian Brauner
bdba9c79c8 ovl: port ovl_copy_up_workdir() to cred guard
Remove the complicated struct ovl_cu_creds dance and use our new copy up
cred guard.

Link: https://patch.msgid.link/20251114-work-ovl-cred-guard-copyup-v1-2-ea3fb15cf427@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:27 +01:00
Christian Brauner
81b77b5b0a ovl: add copy up credential guard
Add a credential guard for copy up. This will allows us to waste struct
struct ovl_cu_creds and simplify the code.

Link: https://patch.msgid.link/20251114-work-ovl-cred-guard-copyup-v1-1-ea3fb15cf427@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:27 +01:00
Christian Brauner
89a11f004f ovl: drop ovl_setup_cred_for_create()
It is now unused and can be removed.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-prepare-v2-6-bd1c97a36d7b@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:26 +01:00
Christian Brauner
e566bff963 ovl: port ovl_create_or_link() to new ovl_override_creator_creds cleanup guard
This clearly indicates the double-credential override and makes the code
a lot easier to grasp with one glance.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-prepare-v2-5-bd1c97a36d7b@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:26 +01:00
Christian Brauner
8a227c2766 ovl: mark ovl_setup_cred_for_create() as unused temporarily
The function will become unused in the next patch.
We'll remove it in later patches to keep the diff legible.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-prepare-v2-4-bd1c97a36d7b@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:26 +01:00
Christian Brauner
d6ef072d09 ovl: reflow ovl_create_or_link()
Reflow the creation routine in preparation of porting it to a guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-prepare-v2-3-bd1c97a36d7b@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:26 +01:00
Christian Brauner
8d7fc461e4 ovl: port ovl_create_tmpfile() to new ovl_override_creator_creds cleanup guard
This clearly indicates the double-credential override and makes the code
a lot easier to grasp with one glance.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-prepare-v2-2-bd1c97a36d7b@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:26 +01:00
Christian Brauner
f37b334728 ovl: add ovl_override_creator_creds cred guard
The current code to override credentials for creation operations is
pretty difficult to understand. We effectively override the credentials
twice:

(1) override with the mounter's credentials
(2) copy the mounts credentials and override the fs{g,u}id with the inode {u,g}id

And then we elide the revert because it would be an idempotent revert.
That elision doesn't buy us anything anymore though because I've made it
all work without any reference counting anyway. All it does is mix the
two credential overrides together.

We can use a cleanup guard to clarify the creation codepaths and make
them easier to understand.

This just introduces the cleanup guard keeping the patch reviewable.
We'll convert the caller in follow-up patches and then drop the
duplicated code.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-prepare-v2-1-bd1c97a36d7b@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:26 +01:00
Christian Brauner
850e32512a ovl: remove ovl_revert_creds()
The wrapper isn't needed anymore. Overlayfs completely relies on its
cleanup guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-42-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:25 +01:00
Christian Brauner
217e78d1b7 ovl: port ovl_fill_super() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-41-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:25 +01:00
Christian Brauner
fc95cda673 ovl: refactor ovl_fill_super()
Split the core into a separate helper in preparation of converting the
caller to the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-40-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:25 +01:00
Christian Brauner
db7cfe8783 ovl: port ovl_lower_positive() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-39-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:25 +01:00
Christian Brauner
6b6ef7d16f ovl: port ovl_lookup() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-38-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:25 +01:00
Christian Brauner
15da486ad3 ovl: refactor ovl_lookup()
Split the core into a separate helper in preparation of converting the
caller to the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-37-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:25 +01:00
Christian Brauner
14d35fda5b ovl: port ovl_copyfile() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-36-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:24 +01:00
Christian Brauner
ca0c657f25 ovl: port ovl_rename() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-35-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:24 +01:00
Christian Brauner
a1da840198 ovl: refactor ovl_rename()
Extract the code that runs under overridden credentials into a separate
ovl_rename_upper() helper function and the code that runs before/after to
ovl_rename_start/end(). Error handling is simplified.
The helpers returns errors directly instead of using goto labels.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-34-b31603935724@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:24 +01:00
Christian Brauner
fb9f31fe9f ovl: introduce struct ovl_renamedata
Add a struct ovl_renamedata to group rename-related state that was
previously stored in local variables. Embedd struct renamedata directly
aligning with the vfs.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-33-b31603935724@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:24 +01:00
Christian Brauner
0b5800172c ovl: port ovl_listxattr() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-32-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:24 +01:00
Christian Brauner
ae64b54185 ovl: port ovl_xattr_get() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-31-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:24 +01:00
Christian Brauner
d605301726 ovl: port ovl_xattr_set() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-30-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:24 +01:00
Christian Brauner
9e5ec68f3a ovl: port ovl_nlink_end() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-29-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:23 +01:00
Christian Brauner
062c5b48d2 ovl: port ovl_nlink_start() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-28-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:23 +01:00
Christian Brauner
67bc75e6f4 ovl: port ovl_check_empty_dir() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-27-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:23 +01:00
Christian Brauner
5517646e14 ovl: port ovl_dir_llseek() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-26-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:23 +01:00
Christian Brauner
d25e4b739f ovl: refactor ovl_iterate() and port to cred guard
factor out ovl_iterate_merged() and move some code into
ovl_iterate_real() for easier use of the scoped ovl cred guard.

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-25-b31603935724@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:23 +01:00
Christian Brauner
198d182288 ovl: don't override credentials for ovl_check_whiteouts()
The function is only called when rdd->dentry is non-NULL:

if (!err && rdd->first_maybe_whiteout && rdd->dentry)
    err = ovl_check_whiteouts(realpath, rdd);

| Caller                        | Sets rdd->dentry? | Can call ovl_check_whiteouts()? |
|-------------------------------|-------------------|---------------------------------|
| ovl_dir_read_merged()         | ✓ Yes (line 430)  | ✓ YES                           |
| ovl_dir_read_impure()         | ✗ No              | ✗ NO                            |
| ovl_check_d_type_supported()  | ✗ No              | ✗ NO                            |
| ovl_workdir_cleanup_recurse() | ✗ No              | ✗ NO                            |
| ovl_indexdir_cleanup()        | ✗ No              | ✗ NO                            |

VFS layer (.iterate_shared file operation)
  → ovl_iterate()
      [CRED OVERRIDE]
      → ovl_cache_get()
          → ovl_dir_read_merged()
              → ovl_dir_read()
                  → ovl_check_whiteouts()
      [CRED REVERT]

ovl_unlink()
  → ovl_do_remove()
      → ovl_check_empty_dir()
          [CRED OVERRIDE]
          → ovl_dir_read_merged()
              → ovl_dir_read()
                  → ovl_check_whiteouts()
          [CRED REVERT]

ovl_rename()
  → ovl_check_empty_dir()
      [CRED OVERRIDE]
      → ovl_dir_read_merged()
          → ovl_dir_read()
              → ovl_check_whiteouts()
      [CRED REVERT]

All valid callchains already override credentials so drop the override.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-24-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:23 +01:00
Christian Brauner
cb3c8cbaed ovl: port ovl_maybe_lookup_lowerdata() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-23-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:23 +01:00
Christian Brauner
b1c47b3abc ovl: port ovl_maybe_validate_verity() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-22-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:22 +01:00
Christian Brauner
4975e683c2 ovl: port ovl_fileattr_get() to cred guard
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>
2025-11-19 21:58:22 +01:00
Christian Brauner
af1d5d62f3 ovl: port ovl_fileattr_set() to cred guard
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>
2025-11-19 21:58:22 +01:00
Christian Brauner
a3860a808f ovl: port ovl_fiemap() to cred guard
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>
2025-11-19 21:58:22 +01:00
Christian Brauner
8e9698d6e4 ovl: port ovl_set_or_remove_acl() to cred guard
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>
2025-11-19 21:58:22 +01:00
Christian Brauner
71ac28fbcd ovl: port do_ovl_get_acl() to cred guard
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>
2025-11-19 21:58:22 +01:00
Christian Brauner
47eba7f7fd ovl: port ovl_get_link() to cred guard
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>
2025-11-19 21:58:22 +01:00
Christian Brauner
d81999b40b ovl: port ovl_permission() to cred guard
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>
2025-11-19 21:58:21 +01:00
Christian Brauner
81707ae827 ovl: port ovl_getattr() to cred guard
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>
2025-11-19 21:58:21 +01:00
Christian Brauner
7aedfa5a52 ovl: port ovl_setattr() to cred guard
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>
2025-11-19 21:58:21 +01:00
Christian Brauner
9763970984 ovl: port ovl_flush() to cred guard
Use the scoped ovl cred guard.

Link: https://patch.msgid.link/20251117-work-ovl-cred-guard-v4-12-b31603935724@kernel.org
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2025-11-19 21:58:21 +01:00