->d_revalidate() often needs to access dentry parent and name; that has
to be done carefully, since the locking environment varies from caller
to caller. We are not guaranteed that dentry in question will not be
moved right under us - not unless the filesystem is such that nothing
on it ever gets renamed.
It can be dealt with, but that results in boilerplate code that isn't
even needed - the callers normally have just found the dentry via dcache
lookup and want to verify that it's in the right place; they already
have the values of ->d_parent and ->d_name stable. There is a couple
of exceptions (overlayfs and, to less extent, ecryptfs), but for the
majority of calls that song and dance is not needed at all.
It's easier to make ecryptfs and overlayfs find and pass those values if
there's a ->d_revalidate() instance to be called, rather than doing that
in the instances.
This commit only changes the calling conventions; making use of supplied
values is left to followups.
NOTE: some instances need more than just the parent - things like CIFS
may need to build an entire path from filesystem root, so they need
more precautions than the usual boilerplate. This series doesn't
do anything to that need - these filesystems have to keep their locking
mechanisms (rename_lock loops, use of dentry_path_raw(), private rwsem
a-la v9fs).
One thing to keep in mind when using name is that name->name will normally
point into the pathname being resolved; the filename in question occupies
name->len bytes starting at name->name, and there is NUL somewhere after it,
but it the next byte might very well be '/' rather than '\0'. Do not
ignore name->len.
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Gabriel Krisman Bertazi <gabriel@krisman.be>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Pull ecryptfs mount api conversion from Christian Brauner:
"Convert ecryptfs to the new mount api"
* tag 'vfs-6.13.ecryptfs.mount.api' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
ecryptfs: Fix spelling mistake "validationg" -> "validating"
ecryptfs: Convert ecryptfs to use the new mount API
ecryptfs: Factor out mount option validation
Pull statx updates from Al Viro:
"Sanitize struct filename and lookup flags handling in statx and
friends"
* tag 'pull-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
libfs: kill empty_dir_getattr()
fs: Simplify getattr interface function checking AT_GETATTR_NOSEC flag
fs/stat.c: switch to CLASS(fd_raw)
kill getname_statx_lookup_flags()
io_statx_prep(): use getname_uflags()
Under the new mount API, mount options are parsed one at a time.
Any validation that examines multiple options must be done after parsing
is complete, so factor out a ecryptfs_validate_options() which can be
called separately.
To facilitate this, temporarily move the local variables that tracked
whether various options have been set in the parsing function, into the
ecryptfs_mount_crypt_stat structure so that they can be examined later.
These will be moved to a more ephemeral struct in the mount api conversion
patch to follow.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Link: https://lore.kernel.org/r/20241028143359.605061-2-sandeen@redhat.com
Acked-by: Tyler Hicks <code@tyhicks.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Commit 8a924db2d7 ("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: 8a924db2d7 ("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>
Remove the conversion to a struct page. Removes a few hidden calls to
compound_head(). Use 'err' instead of 'rc' for clarity.
Also remove the unnecessary call to ClearPageUptodate(); the uptodate
flag is already clear if this function is being called. That lets us
switch to folio_end_read() which does one atomic flag operation instead
of two.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20241025190822.1319162-3-willy@infradead.org
Signed-off-by: Christian Brauner <brauner@kernel.org>
asm/unaligned.h is always an include of asm-generic/unaligned.h;
might as well move that thing to linux/unaligned.h and include
that - there's nothing arch-specific in that header.
auto-generated by the following:
for i in `git grep -l -w asm/unaligned.h`; do
sed -i -e "s/asm\/unaligned.h/linux\/unaligned.h/" $i
done
for i in `git grep -l -w asm-generic/unaligned.h`; do
sed -i -e "s/asm-generic\/unaligned.h/linux\/unaligned.h/" $i
done
git mv include/asm-generic/unaligned.h include/linux/unaligned.h
git mv tools/include/asm-generic/unaligned.h tools/include/linux/unaligned.h
sed -i -e "/unaligned.h/d" include/asm-generic/Kbuild
sed -i -e "s/__ASM_GENERIC/__LINUX/" include/linux/unaligned.h tools/include/linux/unaligned.h
Convert all callers from working on a page to working on one page
of a folio (support for working on an entire folio can come later).
Removes a lot of folio->page->folio conversions.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Most callers have a folio, and most implementations operate on a folio,
so remove the conversion from folio->page->folio to fit through this
interface.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Use __filemap_get_folio() instead of grab_cache_page_write_begin()
and use the folio throughout. No attempt is made here to support
large folios, simply converting this function to use folio APIs is
the goal. Saves many hidden calls to compound_head().
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Convert the passed page to a folio and operate on that.
Replaces four calls to compound_head() with one.
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Pull hardening updates from Kees Cook:
"The bulk of the changes here are related to refactoring and expanding
the KUnit tests for string helper and fortify behavior.
Some trivial strncpy replacements in fs/ were carried in my tree. Also
some fixes to SCSI string handling were carried in my tree since the
helper for those was introduce here. Beyond that, just little fixes
all around: objtool getting confused about LKDTM+KCFI, preparing for
future refactors (constification of sysctl tables, additional
__counted_by annotations), a Clang UBSAN+i386 crash fix, and adding
more options in the hardening.config Kconfig fragment.
Summary:
- selftests: Add str*cmp tests (Ivan Orlov)
- __counted_by: provide UAPI for _le/_be variants (Erick Archer)
- Various strncpy deprecation refactors (Justin Stitt)
- stackleak: Use a copy of soon-to-be-const sysctl table (Thomas
Weißschuh)
- UBSAN: Work around i386 -regparm=3 bug with Clang prior to
version 19
- Provide helper to deal with non-NUL-terminated string copying
- SCSI: Fix older string copying bugs (with new helper)
- selftests: Consolidate string helper behavioral tests
- selftests: add memcpy() fortify tests
- string: Add additional __realloc_size() annotations for "dup"
helpers
- LKDTM: Fix KCFI+rodata+objtool confusion
- hardening.config: Enable KCFI"
* tag 'hardening-6.10-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: (29 commits)
uapi: stddef.h: Provide UAPI macros for __counted_by_{le, be}
stackleak: Use a copy of the ctl_table argument
string: Add additional __realloc_size() annotations for "dup" helpers
kunit/fortify: Fix replaced failure path to unbreak __alloc_size
hardening: Enable KCFI and some other options
lkdtm: Disable CFI checking for perms functions
kunit/fortify: Add memcpy() tests
kunit/fortify: Do not spam logs with fortify WARNs
kunit/fortify: Rename tests to use recommended conventions
init: replace deprecated strncpy with strscpy_pad
kunit/fortify: Fix mismatched kvalloc()/vfree() usage
scsi: qla2xxx: Avoid possible run-time warning with long model_num
scsi: mpi3mr: Avoid possible run-time warning with long manufacturer strings
scsi: mptfusion: Avoid possible run-time warning with long manufacturer strings
fs: ecryptfs: replace deprecated strncpy with strscpy
hfsplus: refactor copy_name to not use strncpy
reiserfs: replace deprecated strncpy with scnprintf
virt: acrn: replace deprecated strncpy with strscpy
ubsan: Avoid i386 UBSAN handler crashes with Clang
ubsan: Remove 1-element array usage in debug reporting
...
