[ Upstream commit 1992330d90 ]
Syzbot reported a KMSAN uninit-value issue in ovl_fill_real.
This iusse's call chain is:
__do_sys_getdents64()
-> iterate_dir()
...
-> ext4_readdir()
-> fscrypt_fname_alloc_buffer() // alloc
-> fscrypt_fname_disk_to_usr // write without tail '\0'
-> dir_emit()
-> ovl_fill_real() // read by strcmp()
The string is used to store the decrypted directory entry name for an
encrypted inode. As shown in the call chain, fscrypt_fname_disk_to_usr()
write it without null-terminate. However, ovl_fill_real() uses strcmp() to
compare the name against "..", which assumes a null-terminated string and
may trigger a KMSAN uninit-value warning when the buffer tail contains
uninit data.
Reported-by: syzbot+d130f98b2c265fae5297@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=d130f98b2c265fae5297
Fixes: 4edb83bb10 ("ovl: constant d_ino for non-merge dirs")
Signed-off-by: Qing Wang <wangqing7171@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://patch.msgid.link/20260128132406.23768-2-amir73il@gmail.com
Acked-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Eric Biggers <ebiggers@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8a39f1c870 ]
In ovl_path_type() and ovl_is_metacopy_dentry() GCC notices that it is
possible for OVL_E() to return NULL (which implies that d_inode(dentry)
may be NULL). This would result in out of bounds reads via container_of(),
seen with GCC 15's -Warray-bounds -fdiagnostics-details. For example:
In file included from arch/x86/include/generated/asm/rwonce.h:1,
from include/linux/compiler.h:339,
from include/linux/export.h:5,
from include/linux/linkage.h:7,
from include/linux/fs.h:5,
from fs/overlayfs/util.c:7:
In function 'ovl_upperdentry_dereference',
inlined from 'ovl_dentry_upper' at ../fs/overlayfs/util.c:305:9,
inlined from 'ovl_path_type' at ../fs/overlayfs/util.c:216:6:
include/asm-generic/rwonce.h:44:26: error: array subscript 0 is outside array bounds of 'struct inode[7486503276667837]' [-Werror=array-bounds=]
44 | #define __READ_ONCE(x) (*(const volatile __unqual_scalar_typeof(x) *)&(x))
| ~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
include/asm-generic/rwonce.h:50:9: note: in expansion of macro '__READ_ONCE'
50 | __READ_ONCE(x); \
| ^~~~~~~~~~~
fs/overlayfs/ovl_entry.h:195:16: note: in expansion of macro 'READ_ONCE'
195 | return READ_ONCE(oi->__upperdentry);
| ^~~~~~~~~
'ovl_path_type': event 1
185 | return inode ? OVL_I(inode)->oe : NULL;
'ovl_path_type': event 2
Avoid this by allowing ovl_dentry_upper() to return NULL if d_inode() is
NULL, as that means the problematic dereferencing can never be reached.
Note that this fixes the over-eager compiler warning in an effort to
being able to enable -Warray-bounds globally. There is no known
behavioral bug here.
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Kees Cook <kees@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 924577e4f6 upstream.
When the lowerdir of an overlayfs is a merged directory of another
overlayfs, ovl_open_realfile() will fail to open the real file and point
to a lower dentry copy, without the proper parent path. After this,
d_path() will then display the path incorrectly as if the file is placed
in the root directory.
This bug can be triggered with the following setup:
mkdir -p ovl-A/lower ovl-A/upper ovl-A/merge ovl-A/work
mkdir -p ovl-B/upper ovl-B/merge ovl-B/work
cp /bin/cat ovl-A/lower/
mount -t overlay overlay -o \
lowerdir=ovl-A/lower,upperdir=ovl-A/upper,workdir=ovl-A/work \
ovl-A/merge
mount -t overlay overlay -o \
lowerdir=ovl-A/merge,upperdir=ovl-B/upper,workdir=ovl-B/work \
ovl-B/merge
ovl-A/merge/cat /proc/self/maps | grep --color cat
ovl-B/merge/cat /proc/self/maps | grep --color cat
The first cat will correctly show `/ovl-A/merge/cat`, while the second
one shows just `/cat`.
To fix that, uses file_user_path() inside of backing_file_open() to get
the correct file path for the dentry.
Co-developed-by: John Schoenick <johns@valvesoftware.com>
Signed-off-by: John Schoenick <johns@valvesoftware.com>
Signed-off-by: André Almeida <andrealmeid@igalia.com>
Fixes: def3ae83da ("fs: store real path instead of fake path in backing file f_path")
Cc: <stable@vger.kernel.org> # v6.7
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit eb3a04a851 upstream.
In theory overlayfs could support upper layer directly referring to a data
layer, but there's no current use case for this.
Originally, when data-only layers were introduced, this wasn't allowed,
only introduced by the "datadir+" feature, but without actually handling
this case, resulting in an Oops.
Fix by disallowing datadir without lowerdir.
Reported-by: Giuseppe Scrivano <gscrivan@redhat.com>
Fixes: 24e16e385f ("ovl: add support for appending lowerdirs one by one")
Cc: <stable@vger.kernel.org> # v6.7
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 974e3fe0ac upstream.
Encoding file handles is usually performed by a filesystem >encode_fh()
method that may fail for various reasons.
The legacy users of exportfs_encode_fh(), namely, nfsd and
name_to_handle_at(2) syscall are ready to cope with the possibility
of failure to encode a file handle.
There are a few other users of exportfs_encode_{fh,fid}() that
currently have a WARN_ON() assertion when ->encode_fh() fails.
Relax those assertions because they are wrong.
The second linked bug report states commit 16aac5ad1f ("ovl: support
encoding non-decodable file handles") in v6.6 as the regressing commit,
but this is not accurate.
The aforementioned commit only increases the chances of the assertion
and allows triggering the assertion with the reproducer using overlayfs,
inotify and drop_caches.
Triggering this assertion was always possible with other filesystems and
other reasons of ->encode_fh() failures and more particularly, it was
also possible with the exact same reproducer using overlayfs that is
mounted with options index=on,nfs_export=on also on kernels < v6.6.
Therefore, I am not listing the aforementioned commit as a Fixes commit.
Backport hint: this patch will have a trivial conflict applying to
v6.6.y, and other trivial conflicts applying to stable kernels < v6.6.
Reported-by: syzbot+ec07f6f5ce62b858579f@syzkaller.appspotmail.com
Tested-by: syzbot+ec07f6f5ce62b858579f@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/linux-unionfs/671fd40c.050a0220.4735a.024f.GAE@google.com/
Reported-by: Dmitry Safonov <dima@arista.com>
Closes: https://lore.kernel.org/linux-fsdevel/CAGrbwDTLt6drB9eaUagnQVgdPBmhLfqqxAf3F+Juqy_o6oP8uw@mail.gmail.com/
Cc: stable@vger.kernel.org
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20241219115301.465396-1-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit c45beebfde ]
Dmitry Safonov reported that a WARN_ON() assertion can be trigered by
userspace when calling inotify_show_fdinfo() for an overlayfs watched
inode, whose dentry aliases were discarded with drop_caches.
The WARN_ON() assertion in inotify_show_fdinfo() was removed, because
it is possible for encoding file handle to fail for other reason, but
the impact of failing to encode an overlayfs file handle goes beyond
this assertion.
As shown in the LTP test case mentioned in the link below, failure to
encode an overlayfs file handle from a non-aliased inode also leads to
failure to report an fid with FAN_DELETE_SELF fanotify events.
As Dmitry notes in his analyzis of the problem, ovl_encode_fh() fails
if it cannot find an alias for the inode, but this failure can be fixed.
ovl_encode_fh() seldom uses the alias and in the case of non-decodable
file handles, as is often the case with fanotify fid info,
ovl_encode_fh() never needs to use the alias to encode a file handle.
Defer finding an alias until it is actually needed so ovl_encode_fh()
will not fail in the common case of FAN_DELETE_SELF fanotify events.
Fixes: 16aac5ad1f ("ovl: support encoding non-decodable file handles")
Reported-by: Dmitry Safonov <dima@arista.com>
Closes: https://lore.kernel.org/linux-fsdevel/CAOQ4uxiie81voLZZi2zXS1BziXZCM24nXqPAxbu8kxXCUWdwOg@mail.gmail.com/
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20250105162404.357058-3-amir73il@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 3b6b99ef15 upstream.
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: 72db82115d ("ovl: copy up sync/noatime fileattr flags")
Cc: stable@vger.kernel.org # v5.15+
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull 'struct fd' updates from Al Viro:
"Just the 'struct fd' layout change, with conversion to accessor
helpers"
* tag 'pull-stable-struct_fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
add struct fd constructors, get rid of __to_fd()
struct fd: representation change
introduce fd_file(), convert all accessors to it.
Pull overlayfs updates from Amir Goldstein:
- Increase robustness of overlayfs to crashes in the case of underlying
filesystems that to not guarantee metadata ordering to persistent
storage (problem was reported with ubifs).
- Deny mount inside container with features that require root
privileges to work properly, instead of failing operations later.
- Some clarifications to overlayfs documentation.
* tag 'ovl-update-6.12' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: fail if trusted xattrs are needed but caller lacks permission
overlayfs.rst: update metacopy section in overlayfs documentation
ovl: fsync after metadata copy-up
ovl: don't set the superblock's errseq_t manually
Pull lsm updates from Paul Moore:
- Move the LSM framework to static calls
This transitions the vast majority of the LSM callbacks into static
calls. Those callbacks which haven't been converted were left as-is
due to the general ugliness of the changes required to support the
static call conversion; we can revisit those callbacks at a future
date.
- Add the Integrity Policy Enforcement (IPE) LSM
This adds a new LSM, Integrity Policy Enforcement (IPE). There is
plenty of documentation about IPE in this patches, so I'll refrain
from going into too much detail here, but the basic motivation behind
IPE is to provide a mechanism such that administrators can restrict
execution to only those binaries which come from integrity protected
storage, e.g. a dm-verity protected filesystem. You will notice that
IPE requires additional LSM hooks in the initramfs, dm-verity, and
fs-verity code, with the associated patches carrying ACK/review tags
from the associated maintainers. We couldn't find an obvious
maintainer for the initramfs code, but the IPE patchset has been
widely posted over several years.
Both Deven Bowers and Fan Wu have contributed to IPE's development
over the past several years, with Fan Wu agreeing to serve as the IPE
maintainer moving forward. Once IPE is accepted into your tree, I'll
start working with Fan to ensure he has the necessary accounts, keys,
etc. so that he can start submitting IPE pull requests to you
directly during the next merge window.
- Move the lifecycle management of the LSM blobs to the LSM framework
Management of the LSM blobs (the LSM state buffers attached to
various kernel structs, typically via a void pointer named "security"
or similar) has been mixed, some blobs were allocated/managed by
individual LSMs, others were managed by the LSM framework itself.
Starting with this pull we move management of all the LSM blobs,
minus the XFRM blob, into the framework itself, improving consistency
across LSMs, and reducing the amount of duplicated code across LSMs.
Due to some additional work required to migrate the XFRM blob, it has
been left as a todo item for a later date; from a practical
standpoint this omission should have little impact as only SELinux
provides a XFRM LSM implementation.
- Fix problems with the LSM's handling of F_SETOWN
The LSM hook for the fcntl(F_SETOWN) operation had a couple of
problems: it was racy with itself, and it was disconnected from the
associated DAC related logic in such a way that the LSM state could
be updated in cases where the DAC state would not. We fix both of
these problems by moving the security_file_set_fowner() hook into the
same section of code where the DAC attributes are updated. Not only
does this resolve the DAC/LSM synchronization issue, but as that code
block is protected by a lock, it also resolve the race condition.
- Fix potential problems with the security_inode_free() LSM hook
Due to use of RCU to protect inodes and the placement of the LSM hook
associated with freeing the inode, there is a bit of a challenge when
it comes to managing any LSM state associated with an inode. The VFS
folks are not open to relocating the LSM hook so we have to get
creative when it comes to releasing an inode's LSM state.
Traditionally we have used a single LSM callback within the hook that
is triggered when the inode is "marked for death", but not actually
released due to RCU.
Unfortunately, this causes problems for LSMs which want to take an
action when the inode's associated LSM state is actually released; so
we add an additional LSM callback, inode_free_security_rcu(), that is
called when the inode's LSM state is released in the RCU free
callback.
- Refactor two LSM hooks to better fit the LSM return value patterns
The vast majority of the LSM hooks follow the "return 0 on success,
negative values on failure" pattern, however, there are a small
handful that have unique return value behaviors which has caused
confusion in the past and makes it difficult for the BPF verifier to
properly vet BPF LSM programs. This includes patches to
convert two of these"special" LSM hooks to the common 0/-ERRNO pattern.
- Various cleanups and improvements
A handful of patches to remove redundant code, better leverage the
IS_ERR_OR_NULL() helper, add missing "static" markings, and do some
minor style fixups.
* tag 'lsm-pr-20240911' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (40 commits)
security: Update file_set_fowner documentation
fs: Fix file_set_fowner LSM hook inconsistencies
lsm: Use IS_ERR_OR_NULL() helper function
lsm: remove LSM_COUNT and LSM_CONFIG_COUNT
ipe: Remove duplicated include in ipe.c
lsm: replace indirect LSM hook calls with static calls
lsm: count the LSMs enabled at compile time
kernel: Add helper macros for loop unrolling
init/main.c: Initialize early LSMs after arch code, static keys and calls.
MAINTAINERS: add IPE entry with Fan Wu as maintainer
documentation: add IPE documentation
ipe: kunit test for parser
scripts: add boot policy generation program
ipe: enable support for fs-verity as a trust provider
fsverity: expose verified fsverity built-in signatures to LSMs
lsm: add security_inode_setintegrity() hook
ipe: add support for dm-verity as a trust provider
dm-verity: expose root hash digest and signature data to LSMs
block,lsm: add LSM blob and new LSM hooks for block devices
ipe: add permissive toggle
...
Some overlayfs features require permission to read/write trusted.*
xattrs. These include redirect_dir, verity, metacopy, and data-only
layers. This patch adds additional validations at mount time to stop
overlays from mounting in certain cases where the resulting mount would
not function according to the user's expectations because they lack
permission to access trusted.* xattrs (for example, not global root.)
Similar checks in ovl_make_workdir() that disable features instead of
failing are still relevant and used in cases where the resulting mount
can still work "reasonably well." Generally, if the feature was enabled
through kernel config or module option, any mount that worked before
will still work the same; this applies to redirect_dir and metacopy. The
user must explicitly request these features in order to generate a mount
failure. Verity and data-only layers on the other hand must be explictly
requested and have no "reasonable" disabled or degraded alternative, so
mounts attempting either always fail.
"lower data-only dirs require metacopy support" moved down in case
userxattr is set, which disables metacopy.
Cc: stable@vger.kernel.org # v6.6+
Signed-off-by: Mike Baynton <mike@mbaynton.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
For upper filesystems which do not use strict ordering of persisting
metadata changes (e.g. ubifs), when overlayfs file is modified for
the first time, copy up will create a copy of the lower file and
its parent directories in the upper layer. Permission lost of the
new upper parent directory was observed during power-cut stress test.
Fix by moving the fsync call to after metadata copy to make sure that the
metadata copied up directory and files persists to disk before renaming
from tmp to final destination.
With metacopy enabled, this change will hurt performance of workloads
such as chown -R, so we keep the legacy behavior of fsync only on copyup
of data.
Link: https://lore.kernel.org/linux-unionfs/CAOQ4uxj-pOvmw1-uXR3qVdqtLjSkwcR9nVKcNU_vC10Zyf2miQ@mail.gmail.com/
Reported-and-tested-by: Fei Lv <feilv@asrmicro.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Since commit 5679897eb1 ("vfs: make sync_filesystem return errors from
->sync_fs"), the return value from sync_fs callback can be seen in
sync_filesystem(). Thus the errseq_set opreation can be removed here.
Depends-on: commit 5679897eb1 ("vfs: make sync_filesystem return errors from ->sync_fs")
Signed-off-by: Haifeng Xu <haifeng.xu@shopee.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
The max count of lowerdir is OVL_MAX_STACK[500], which is broken by
commit 37f32f526438("ovl: fix memory leak in ovl_parse_param()") for
parameter Opt_lowerdir. Since commit 819829f0319a("ovl: refactor layer
parsing helpers") and commit 24e16e385f22("ovl: add support for
appending lowerdirs one by one") added check ovl_mount_dir_check() in
function ovl_parse_param_lowerdir(), the 'ctx->nr' should be smaller
than OVL_MAX_STACK, after commit 37f32f526438("ovl: fix memory leak in
ovl_parse_param()") is applied, the 'ctx->nr' is updated before the
check ovl_mount_dir_check(), which leads the max count of lowerdir
to become 499 for parameter Opt_lowerdir.
Fix it by replacing lower layers parsing code with the existing helper
function ovl_parse_layer().
Fixes: 37f32f5264 ("ovl: fix memory leak in ovl_parse_param()")
Signed-off-by: Zhihao Cheng <chengzhihao1@huawei.com>
Link: https://lore.kernel.org/r/20240705011510.794025-3-chengzhihao1@huawei.com
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
We want the compiler to see that fdput() on empty instance
is a no-op. The emptiness check is that file reference is NULL,
while fdput() is "fput() if FDPUT_FPUT is present in flags".
The reason why fdput() on empty instance is a no-op is something
compiler can't see - it's that we never generate instances with
NULL file reference combined with non-zero flags.
It's not that hard to deal with - the real primitives behind
fdget() et.al. are returning an unsigned long value, unpacked by (inlined)
__to_fd() into the current struct file * + int. The lower bits are
used to store flags, while the rest encodes the pointer. Linus suggested
that keeping this unsigned long around with the extractions done by inlined
accessors should generate a sane code and that turns out to be the case.
Namely, turning struct fd into a struct-wrapped unsinged long, with
fd_empty(f) => unlikely(f.word == 0)
fd_file(f) => (struct file *)(f.word & ~3)
fdput(f) => if (f.word & 1) fput(fd_file(f))
ends up with compiler doing the right thing. The cost is the patch
footprint, of course - we need to switch f.file to fd_file(f) all over
the tree, and it's not doable with simple search and replace; there are
false positives, etc.
Note that the sole member of that structure is an opaque
unsigned long - all accesses should be done via wrappers and I don't
want to use a name that would invite manual casts to file pointers,
etc. The value of that member is equal either to (unsigned long)p | flags,
p being an address of some struct file instance, or to 0 for an empty fd.
For now the new predicate (fd_empty(f)) has no users; all the
existing checks have form (!fd_file(f)). We will convert to fd_empty()
use later; here we only define it (and tell the compiler that it's
unlikely to return true).
This commit only deals with representation change; there will
be followups.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
For any changes of struct fd representation we need to
turn existing accesses to fields into calls of wrappers.
Accesses to struct fd::flags are very few (3 in linux/file.h,
1 in net/socket.c, 3 in fs/overlayfs/file.c and 3 more in
explicit initializers).
Those can be dealt with in the commit converting to
new layout; accesses to struct fd::file are too many for that.
This commit converts (almost) all of f.file to
fd_file(f). It's not entirely mechanical ('file' is used as
a member name more than just in struct fd) and it does not
even attempt to distinguish the uses in pointer context from
those in boolean context; the latter will be eventually turned
into a separate helper (fd_empty()).
NOTE: mass conversion to fd_empty(), tempting as it
might be, is a bad idea; better do that piecewise in commit
that convert from fdget...() to CLASS(...).
[conflicts in fs/fhandle.c, kernel/bpf/syscall.c, mm/memcontrol.c
caught by git; fs/stat.c one got caught by git grep]
[fs/xattr.c conflict]
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
To be consistent with most LSM hooks, convert the return value of
hook inode_copy_up_xattr to 0 or a negative error code.
Before:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, 1 when
discarding xattr, -EOPNOTSUPP if it does not know xattr, or any
other negative error code otherwise.
After:
- Hook inode_copy_up_xattr returns 0 when accepting xattr, *-ECANCELED*
when discarding xattr, -EOPNOTSUPP if it does not know xattr, or
any other negative error code otherwise.
Signed-off-by: Xu Kuohai <xukuohai@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
ovl_check_encode_origin() should return a positive number if the lower
dentry is to be encoded, zero otherwise. If there's no upper layer at all
(read-only overlay), then it obviously needs to return positive.
This was broken by commit 16aac5ad1f ("ovl: support encoding
non-decodable file handles"), which didn't take the lower-only
configuration into account.
Fix by checking the no-upper-layer case up-front.
Reported-and-tested-by: Youzhong Yang <youzhong@gmail.com>
Closes: https://lore.kernel.org/all/CADpNCvaBimi+zCYfRJHvCOhMih8OU0rmZkwLuh24MKKroRuT8Q@mail.gmail.com/
Fixes: 16aac5ad1f ("ovl: support encoding non-decodable file handles")
Cc: <stable@vger.kernel.org> # v6.6
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Pull overlayfs updates from Miklos Szeredi:
- Add tmpfile support
- Clean up include
* tag 'ovl-update-6.10' of git://git.kernel.org/pub/scm/linux/kernel/git/overlayfs/vfs:
ovl: remove duplicate included header
ovl: remove upper umask handling from ovl_create_upper()
ovl: implement tmpfile
Pull misc vfs updates from Al Viro:
"Assorted commits that had missed the last merge window..."
* tag 'pull-misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
remove call_{read,write}_iter() functions
do_dentry_open(): kill inode argument
kernel_file_open(): get rid of inode argument
get_file_rcu(): no need to check for NULL separately
fd_is_open(): move to fs/file.c
close_on_exec(): pass files_struct instead of fdtable
Pull integrity updates from Mimi Zohar:
"Two IMA changes, one EVM change, a use after free bug fix, and a code
cleanup to address "-Wflex-array-member-not-at-end" warnings:
- The existing IMA {ascii, binary}_runtime_measurements lists include
a hard coded SHA1 hash. To address this limitation, define per TPM
enabled hash algorithm {ascii, binary}_runtime_measurements lists
- Close an IMA integrity init_module syscall measurement gap by
defining a new critical-data record
- Enable (partial) EVM support on stacked filesystems (overlayfs).
Only EVM portable & immutable file signatures are copied up, since
they do not contain filesystem specific metadata"
* tag 'integrity-v6.10' of ssh://ra.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
ima: add crypto agility support for template-hash algorithm
evm: Rename is_unsupported_fs to is_unsupported_hmac_fs
fs: Rename SB_I_EVM_UNSUPPORTED to SB_I_EVM_HMAC_UNSUPPORTED
evm: Enforce signatures on unsupported filesystem for EVM_INIT_X509
ima: re-evaluate file integrity on file metadata change
evm: Store and detect metadata inode attributes changes
ima: Move file-change detection variables into new structure
evm: Use the metadata inode to calculate metadata hash
evm: Implement per signature type decision in security_inode_copy_up_xattr
security: allow finer granularity in permitting copy-up of security xattrs
ima: Rename backing_inode to real_inode
integrity: Avoid -Wflex-array-member-not-at-end warnings
ima: define an init_module critical data record
ima: Fix use-after-free on a dentry's dname.name
This is already done by vfs_prepare_mode() when creating the upper object
by vfs_create(), vfs_mkdir() and vfs_mknod().
No regressions have been observed in xfstests run with posix acls turned
off for the upper filesystem.
Fixes: 1639a49ccd ("fs: move S_ISGID stripping into the vfs_*() helpers")
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Combine inode creation with opening a file.
There are six separate objects that are being set up: the backing inode,
dentry and file, and the overlay inode, dentry and file. Cleanup in case
of an error is a bit of a challenge and is difficult to test, so careful
review is needed.
All tmpfile testcases except generic/509 now run/pass, and no regressions
are observed with full xfstests.
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
always equal to ->dentry->d_inode of the path argument these
days.
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Now that EVM supports RSA signatures for previously completely
unsupported filesystems rename the flag SB_I_EVM_UNSUPPORTED to
SB_I_EVM_HMAC_UNSUPPORTED to reflect that only HMAC is not supported.
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Copying up xattrs is solely based on the security xattr name. For finer
granularity add a dentry parameter to the security_inode_copy_up_xattr
hook definition, allowing decisions to be based on the xattr content as
well.
Co-developed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Paul Moore <paul@paul-moore.com> (LSM,SELinux)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
syzbot hit an assertion in copy up data loop which looks like it is
the result of a lower file whose size is being changed underneath
overlayfs.
This type of use case is documented to cause undefined behavior, so
returning EIO error for the copy up makes sense, but it should not be
causing a WARN_ON assertion.
Reported-and-tested-by: syzbot+3abd99031b42acf367ef@syzkaller.appspotmail.com
Fixes: ca7ab48240 ("ovl: add permission hooks outside of do_splice_direct()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Yes, yes, I know the slab people were planning on going slow and letting
every subsystem fight this thing on their own. But let's just rip off
the band-aid and get it over and done with. I don't want to see a
number of unnecessary pull requests just to get rid of a flag that no
longer has any meaning.
This was mainly done with a couple of 'sed' scripts and then some manual
cleanup of the end result.
Link: https://lore.kernel.org/all/CAHk-=wji0u+OOtmAOD-5JV3SXcRJF___k_+8XNKmak0yd5vW1Q@mail.gmail.com/
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Pull vfs uuid updates from Christian Brauner:
"This adds two new ioctl()s for getting the filesystem uuid and
retrieving the sysfs path based on the path of a mounted filesystem.
Getting the filesystem uuid has been implemented in filesystem
specific code for a while it's now lifted as a generic ioctl"
* tag 'vfs-6.9.uuid' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
xfs: add support for FS_IOC_GETFSSYSFSPATH
fs: add FS_IOC_GETFSSYSFSPATH
fat: Hook up sb->s_uuid
fs: FS_IOC_GETUUID
ovl: convert to super_set_uuid()
fs: super_set_uuid()
Pull misc vfs updates from Christian Brauner:
"Misc features, cleanups, and fixes for vfs and individual filesystems.
Features:
- Support idmapped mounts for hugetlbfs.
- Add RWF_NOAPPEND flag for pwritev2(). This allows us to fix a bug
where the passed offset is ignored if the file is O_APPEND. The new
flag allows a caller to enforce that the offset is honored to
conform to posix even if the file was opened in append mode.
- Move i_mmap_rwsem in struct address_space to avoid false sharing
between i_mmap and i_mmap_rwsem.
- Convert efs, qnx4, and coda to use the new mount api.
- Add a generic is_dot_dotdot() helper that's used by various
filesystems and the VFS code instead of open-coding it multiple
times.
- Recently we've added stable offsets which allows stable ordering
when iterating directories exported through NFS on e.g., tmpfs
filesystems. Originally an xarray was used for the offset map but
that caused slab fragmentation issues over time. This switches the
offset map to the maple tree which has a dense mode that handles
this scenario a lot better. Includes tests.
- Finally merge the case-insensitive improvement series Gabriel has
been working on for a long time. This cleanly propagates case
insensitive operations through ->s_d_op which in turn allows us to
remove the quite ugly generic_set_encrypted_ci_d_ops() operations.
It also improves performance by trying a case-sensitive comparison
first and then fallback to case-insensitive lookup if that fails.
This also fixes a bug where overlayfs would be able to be mounted
over a case insensitive directory which would lead to all sort of
odd behaviors.
Cleanups:
- Make file_dentry() a simple accessor now that ->d_real() is
simplified because of the backing file work we did the last two
cycles.
- Use the dedicated file_mnt_idmap helper in ntfs3.
- Use smp_load_acquire/store_release() in the i_size_read/write
helpers and thus remove the hack to handle i_size reads in the
filemap code.
- The SLAB_MEM_SPREAD is a nop now. Remove it from various places in
fs/
- It's no longer necessary to perform a second built-in initramfs
unpack call because we retain the contents of the previous
extraction. Remove it.
- Now that we have removed various allocators kfree_rcu() always
works with kmem caches and kmalloc(). So simplify various places
that only use an rcu callback in order to handle the kmem cache
case.
- Convert the pipe code to use a lockdep comparison function instead
of open-coding the nesting making lockdep validation easier.
- Move code into fs-writeback.c that was located in a header but can
be made static as it's only used in that one file.
- Rewrite the alignment checking iterators for iovec and bvec to be
easier to read, and also significantly more compact in terms of
generated code. This saves 270 bytes of text on x86-64 (with
clang-18) and 224 bytes on arm64 (with gcc-13). In profiles it also
saves a bit of time for the same workload.
- Switch various places to use KMEM_CACHE instead of
kmem_cache_create().
- Use inode_set_ctime_to_ts() in inode_set_ctime_current()
- Use kzalloc() in name_to_handle_at() to avoid kernel infoleak.
- Various smaller cleanups for eventfds.
Fixes:
- Fix various comments and typos, and unneeded initializations.
- Fix stack allocation hack for clang in the select code.
- Improve dump_mapping() debug code on a best-effort basis.
- Fix build errors in various selftests.
- Avoid wrap-around instrumentation in various places.
- Don't allow user namespaces without an idmapping to be used for
idmapped mounts.
- Fix sysv sb_read() call.
- Fix fallback implementation of the get_name() export operation"
* tag 'vfs-6.9.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (70 commits)
hugetlbfs: support idmapped mounts
qnx4: convert qnx4 to use the new mount api
fs: use inode_set_ctime_to_ts to set inode ctime to current time
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
efs: remove SLAB_MEM_SPREAD flag usage
jfs: remove SLAB_MEM_SPREAD flag usage
minix: remove SLAB_MEM_SPREAD flag usage
openpromfs: remove SLAB_MEM_SPREAD flag usage
proc: remove SLAB_MEM_SPREAD flag usage
qnx6: remove SLAB_MEM_SPREAD flag usage
...
Merge case-insensitive updates from Gabriel Krisman Bertazi:
- Patch case-insensitive lookup by trying the case-exact comparison
first, before falling back to costly utf8 casefolded comparison.
- Fix to forbid using a case-insensitive directory as part of an
overlayfs mount.
- Patchset to ensure d_op are set at d_alloc time for fscrypt and
casefold volumes, ensuring filesystem dentries will all have the
correct ops, whether they come from a lookup or not.
* tag 'for-next-6.9' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/krisman/unicode:
libfs: Drop generic_set_encrypted_ci_d_ops
ubifs: Configure dentry operations at dentry-creation time
f2fs: Configure dentry operations at dentry-creation time
ext4: Configure dentry operations at dentry-creation time
libfs: Add helper to choose dentry operations at mount-time
libfs: Merge encrypted_ci_dentry_ops and ci_dentry_ops
fscrypt: Drop d_revalidate once the key is added
fscrypt: Drop d_revalidate for valid dentries during lookup
fscrypt: Factor out a helper to configure the lookup dentry
ovl: Always reject mounting over case-insensitive directories
libfs: Attempt exact-match comparison first during casefolded lookup
Signed-off-by: Christian Brauner <brauner@kernel.org>
overlayfs relies on the filesystem setting DCACHE_OP_HASH or
DCACHE_OP_COMPARE to reject mounting over case-insensitive directories.
Since commit bb9cd9106b ("fscrypt: Have filesystems handle their
d_ops"), we set ->d_op through a hook in ->d_lookup, which
means the root dentry won't have them, causing the mount to accidentally
succeed.
In v6.7-rc7, the following sequence will succeed to mount, but any
dentry other than the root dentry will be a "weird" dentry to ovl and
fail with EREMOTE.
mkfs.ext4 -O casefold lower.img
mount -O loop lower.img lower
mount -t overlay -o lowerdir=lower,upperdir=upper,workdir=work ovl /mnt
Mounting on a subdirectory fails, as expected, because DCACHE_OP_HASH
and DCACHE_OP_COMPARE are properly set by ->lookup.
Fix by explicitly rejecting superblocks that allow case-insensitive
dentries. Yes, this will be solved when we move d_op configuration back
to ->s_d_op. Yet, we better have an explicit fix to avoid messing up
again.
While there, re-sort the entries to have more descriptive error messages
first.
Fixes: bb9cd9106b ("fscrypt: Have filesystems handle their d_ops")
Acked-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eric Biggers <ebiggers@google.com>
Link: https://lore.kernel.org/r/20240221171412.10710-2-krisman@suse.de
Signed-off-by: Gabriel Krisman Bertazi <krisman@suse.de>
Pull vfs fixes from Christian Brauner:
- Fix performance regression introduced by moving the security
permission hook out of do_clone_file_range() and into its caller
vfs_clone_file_range().
This causes the security hook to be called in situation were it
wasn't called before as the fast permission checks were left in
do_clone_file_range().
Fix this by merging the two implementations back together and
restoring the old ordering: fast permission checks first, expensive
ones later.
- Tweak mount_setattr() permission checking so that mount properties on
the real rootfs can be changed.
When we added mount_setattr() we added additional checks compared to
legacy mount(2). If the mount had a parent then verify that the
caller and the mount namespace the mount is attached to match and if
not make sure that it's an anonymous mount.
But the real rootfs falls into neither category. It is neither an
anoymous mount because it is obviously attached to the initial mount
namespace but it also obviously doesn't have a parent mount. So that
means legacy mount(2) allows changing mount properties on the real
rootfs but mount_setattr(2) blocks this. This causes regressions (See
the commit for details).
Fix this by relaxing the check. If the mount has a parent or if it
isn't a detached mount, verify that the mount namespaces of the
caller and the mount are the same. Technically, we could probably
write this even simpler and check that the mount namespaces match if
it isn't a detached mount. But the slightly longer check makes it
clearer what conditions one needs to think about.
* tag 'vfs-6.8-rc5.fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
fs: relax mount_setattr() permission checks
remap_range: merge do_clone_file_range() into vfs_clone_file_range()
commit dfad37051a ("remap_range: move permission hooks out of
do_clone_file_range()") moved the permission hooks from
do_clone_file_range() out to its caller vfs_clone_file_range(),
but left all the fast sanity checks in do_clone_file_range().
This makes the expensive security hooks be called in situations
that they would not have been called before (e.g. fs does not support
clone).
The only reason for the do_clone_file_range() helper was that overlayfs
did not use to be able to call vfs_clone_file_range() from copy up
context with sb_writers lock held. However, since commit c63e56a4a6
("ovl: do not open/llseek lower file with upper sb_writers held"),
overlayfs just uses an open coded version of vfs_clone_file_range().
Merge_clone_file_range() into vfs_clone_file_range(), restoring the
original order of checks as it was before the regressing commit and adapt
the overlayfs code to call vfs_clone_file_range() before the permission
hooks that were added by commit ca7ab48240 ("ovl: add permission hooks
outside of do_splice_direct()").
Note that in the merge of do_clone_file_range(), the file_start_write()
context was reduced to cover ->remap_file_range() without holding it
over the permission hooks, which was the reason for doing the regressing
commit in the first place.
Reported-and-tested-by: kernel test robot <oliver.sang@intel.com>
Closes: https://lore.kernel.org/oe-lkp/202401312229.eddeb9a6-oliver.sang@intel.com
Fixes: dfad37051a ("remap_range: move permission hooks out of do_clone_file_range()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20240202102258.1582671-1-amir73il@gmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
The only remaining user of ->d_real() method is d_real_inode(), which
passed NULL inode argument to get the real data dentry.
There are no longer any users that call ->d_real() with a non-NULL
inode argument for getting a detry from a specific underlying layer.
Remove the inode argument of the method and replace it with an integer
'type' argument, to allow callers to request the real metadata dentry
instead of the real data dentry.
All the current users of d_real_inode() (e.g. uprobe) continue to get
the real data inode. Caller that need to get the real metadata inode
(e.g. IMA/EVM) can use d_inode(d_real(dentry, D_REAL_METADATA)).
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/r/20240202110132.1584111-3-amir73il@gmail.com
Tested-by: Stefan Berger <stefanb@linux.ibm.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Christian Brauner <brauner@kernel.org>
An opaque directory cannot have xwhiteouts, so instead of marking an
xwhiteouts directory with a new xattr, overload overlay.opaque xattr
for marking both opaque dir ('y') and xwhiteouts dir ('x').
This is more efficient as the overlay.opaque xattr is checked during
lookup of directory anyway.
This also prevents unnecessary checking the xattr when reading a
directory without xwhiteouts, i.e. most of the time.
Note that the xwhiteouts marker is not checked on the upper layer and
on the last layer in lowerstack, where xwhiteouts are not expected.
Fixes: bc8df7a3dc ("ovl: Add an alternative type of whiteout")
Cc: <stable@vger.kernel.org> # v6.7
Reviewed-by: Alexander Larsson <alexl@redhat.com>
Tested-by: Alexander Larsson <alexl@redhat.com>
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
