If the SMACK64TRANSMUTE xattr is provided, and the inode is a directory,
update the in-memory inode flags by setting SMK_INODE_TRANSMUTE.
Cc: stable@vger.kernel.org
Fixes: 5c6d1125f8 ("Smack: Transmute labels on specified directories") # v2.6.38.x
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Since the SMACK64TRANSMUTE xattr makes sense only for directories, enforce
this restriction in smack_inode_setxattr().
Cc: stable@vger.kernel.org
Fixes: 5c6d1125f8 ("Smack: Transmute labels on specified directories") # v2.6.38.x
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Pull io_uring updates from Jens Axboe:
"Mostly just come fixes and cleanups, but one feature as well. In
detail:
- Harden the check for handling IOPOLL based on return (Pavel)
- Various minor optimizations (Pavel)
- Drop remnants of SCM_RIGHTS fd passing support, now that it's no
longer supported since 6.7 (me)
- Fix for a case where bytes_done wasn't initialized properly on a
failure condition for read/write requests (me)
- Move the register related code to a separate file (me)
- Add support for returning the provided ring buffer head (me)
- Add support for adding a direct descriptor to the normal file table
(me, Christian Brauner)
- Fix for ensuring pending task_work for a ring with DEFER_TASKRUN is
run even if we timeout waiting (me)"
* tag 'for-6.8/io_uring-2024-01-08' of git://git.kernel.dk/linux:
io_uring: ensure local task_work is run on wait timeout
io_uring/kbuf: add method for returning provided buffer ring head
io_uring/rw: ensure io->bytes_done is always initialized
io_uring: drop any code related to SCM_RIGHTS
io_uring/unix: drop usage of io_uring socket
io_uring/register: move io_uring_register(2) related code to register.c
io_uring/openclose: add support for IORING_OP_FIXED_FD_INSTALL
io_uring/cmd: inline io_uring_cmd_get_task
io_uring/cmd: inline io_uring_cmd_do_in_task_lazy
io_uring: split out cmd api into a separate header
io_uring: optimise ltimeout for inline execution
io_uring: don't check iopoll if request completes
Pull header cleanups from Kent Overstreet:
"The goal is to get sched.h down to a type only header, so the main
thing happening in this patchset is splitting out various _types.h
headers and dependency fixups, as well as moving some things out of
sched.h to better locations.
This is prep work for the memory allocation profiling patchset which
adds new sched.h interdepencencies"
* tag 'header_cleanup-2024-01-10' of https://evilpiepirate.org/git/bcachefs: (51 commits)
Kill sched.h dependency on rcupdate.h
kill unnecessary thread_info.h include
Kill unnecessary kernel.h include
preempt.h: Kill dependency on list.h
rseq: Split out rseq.h from sched.h
LoongArch: signal.c: add header file to fix build error
restart_block: Trim includes
lockdep: move held_lock to lockdep_types.h
sem: Split out sem_types.h
uidgid: Split out uidgid_types.h
seccomp: Split out seccomp_types.h
refcount: Split out refcount_types.h
uapi/linux/resource.h: fix include
x86/signal: kill dependency on time.h
syscall_user_dispatch.h: split out *_types.h
mm_types_task.h: Trim dependencies
Split out irqflags_types.h
ipc: Kill bogus dependency on spinlock.h
shm: Slim down dependencies
workqueue: Split out workqueue_types.h
...
Some ioctl commands do not require ioctl permission, but are routed to
other permissions such as FILE_GETATTR or FILE_SETATTR. This routing is
done by comparing the ioctl cmd to a set of 64-bit flags (FS_IOC_*).
However, if a 32-bit process is running on a 64-bit kernel, it emits
32-bit flags (FS_IOC32_*) for certain ioctl operations. These flags are
being checked erroneously, which leads to these ioctl operations being
routed to the ioctl permission, rather than the correct file
permissions.
This was also noted in a RED-PEN finding from a while back -
"/* RED-PEN how should LSM module know it's handling 32bit? */".
This patch introduces a new hook, security_file_ioctl_compat(), that is
called from the compat ioctl syscall. All current LSMs have been changed
to support this hook.
Reviewing the three places where we are currently using
security_file_ioctl(), it appears that only SELinux needs a dedicated
compat change; TOMOYO and SMACK appear to be functional without any
change.
Cc: stable@vger.kernel.org
Fixes: 0b24dcb7f2 ("Revert "selinux: simplify ioctl checking"")
Signed-off-by: Alfred Piccioni <alpic@google.com>
Reviewed-by: Stephen Smalley <stephen.smalley.work@gmail.com>
[PM: subject tweak, line length fixes, and alignment corrections]
Signed-off-by: Paul Moore <paul@paul-moore.com>
As the kernel test robot helpfully reminded us, all of the lsm_id
instances defined inside the various LSMs should be marked as static.
The one exception is Landlock which uses its lsm_id variable across
multiple source files with an extern declaration in a header file.
Reported-by: kernel test robot <lkp@intel.com>
Suggested-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
While we have a lsm_fill_user_ctx() helper function designed to make
life easier for LSMs which return lsm_ctx structs to userspace, we
didn't include all of the buffer length safety checks and buffer
padding adjustments in the helper. This led to code duplication
across the different LSMs and the possibility for mistakes across the
different LSM subsystems. In order to reduce code duplication and
decrease the chances of silly mistakes, we're consolidating all of
this code into the lsm_fill_user_ctx() helper.
The buffer padding is also modified from a fixed 8-byte alignment to
an alignment that matches the word length of the machine
(BITS_PER_LONG / 8).
Signed-off-by: Paul Moore <paul@paul-moore.com>
Create a struct lsm_id to contain identifying information about Linux
Security Modules (LSMs). At inception this contains the name of the
module and an identifier associated with the security module. Change
the security_add_hooks() interface to use this structure. Change the
individual modules to maintain their own struct lsm_id and pass it to
security_add_hooks().
The values are for LSM identifiers are defined in a new UAPI
header file linux/lsm.h. Each existing LSM has been updated to
include it's LSMID in the lsm_id.
The LSM ID values are sequential, with the oldest module
LSM_ID_CAPABILITY being the lowest value and the existing modules
numbered in the order they were included in the main line kernel.
This is an arbitrary convention for assigning the values, but
none better presents itself. The value 0 is defined as being invalid.
The values 1-99 are reserved for any special case uses which may
arise in the future. This may include attributes of the LSM
infrastructure itself, possibly related to namespacing or network
attribute management. A special range is identified for such attributes
to help reduce confusion for developers unfamiliar with LSMs.
LSM attribute values are defined for the attributes presented by
modules that are available today. As with the LSM IDs, The value 0
is defined as being invalid. The values 1-99 are reserved for any
special case uses which may arise in the future.
Cc: linux-security-module <linux-security-module@vger.kernel.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Kees Cook <keescook@chromium.org>
Reviewed-by: Serge Hallyn <serge@hallyn.com>
Reviewed-by: Mickael Salaun <mic@digikod.net>
Reviewed-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Nacked-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
[PM: forward ported beyond v6.6 due merge window changes]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull smack updates from Casey Schaufler:
"Two minor fixes: is a simple spelling fix. The other is a bounds check
for a very likely underflow"
* tag 'Smack-for-6.6' of https://github.com/cschaufler/smack-next:
smackfs: Prevent underflow in smk_set_cipso()
security: smack: smackfs: fix typo (lables->labels)
Pull LSM updates from Paul Moore:
- Add proper multi-LSM support for xattrs in the
security_inode_init_security() hook
Historically the LSM layer has only allowed a single LSM to add an
xattr to an inode, with IMA/EVM measuring that and adding its own as
well. As we work towards promoting IMA/EVM to a "proper LSM" instead
of the special case that it is now, we need to better support the
case of multiple LSMs each adding xattrs to an inode and after
several attempts we now appear to have something that is working
well. It is worth noting that in the process of making this change we
uncovered a problem with Smack's SMACK64TRANSMUTE xattr which is also
fixed in this pull request.
- Additional LSM hook constification
Two patches to constify parameters to security_capget() and
security_binder_transfer_file(). While I generally don't make a
special note of who submitted these patches, these were the work of
an Outreachy intern, Khadija Kamran, and that makes me happy;
hopefully it does the same for all of you reading this.
- LSM hook comment header fixes
One patch to add a missing hook comment header, one to fix a minor
typo.
- Remove an old, unused credential function declaration
It wasn't clear to me who should pick this up, but it was trivial,
obviously correct, and arguably the LSM layer has a vested interest
in credentials so I merged it. Sadly I'm now noticing that despite my
subject line cleanup I didn't cleanup the "unsued" misspelling, sigh
* tag 'lsm-pr-20230829' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm:
lsm: constify the 'file' parameter in security_binder_transfer_file()
lsm: constify the 'target' parameter in security_capget()
lsm: add comment block for security_sk_classify_flow LSM hook
security: Fix ret values doc for security_inode_init_security()
cred: remove unsued extern declaration change_create_files_as()
evm: Support multiple LSMs providing an xattr
evm: Align evm_inode_init_security() definition with LSM infrastructure
smack: Set the SMACK64TRANSMUTE xattr in smack_inode_init_security()
security: Allow all LSMs to provide xattrs for inode_init_security hook
lsm: fix typo in security_file_lock() comment header
There is a upper bound to "catlen" but no lower bound to prevent
negatives. I don't see that this necessarily causes a problem but we
may as well be safe.
Fixes: e114e47377 ("Smack: Simplified Mandatory Access Control Kernel")
Signed-off-by: Dan Carpenter <dan.carpenter@linaro.org>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
With the newly added ability of LSMs to supply multiple xattrs, set
SMACK64TRASMUTE in smack_inode_init_security(), instead of d_instantiate().
Do it by incrementing SMACK_INODE_INIT_XATTRS to 2 and by calling
lsm_get_xattr_slot() a second time, if the transmuting conditions are met.
The LSM infrastructure passes all xattrs provided by LSMs to the
filesystems through the initxattrs() callback, so that filesystems can
store xattrs in the disk.
After the change, the SMK_INODE_TRANSMUTE inode flag is always set by
d_instantiate() after fetching SMACK64TRANSMUTE from the disk. Before it
was done by smack_inode_post_setxattr() as result of the __vfs_setxattr()
call.
Removing __vfs_setxattr() also prevents invalidating the EVM HMAC, by
adding a new xattr without checking and updating the existing HMAC.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Currently, the LSM infrastructure supports only one LSM providing an xattr
and EVM calculating the HMAC on that xattr, plus other inode metadata.
Allow all LSMs to provide one or multiple xattrs, by extending the security
blob reservation mechanism. Introduce the new lbs_xattr_count field of the
lsm_blob_sizes structure, so that each LSM can specify how many xattrs it
needs, and the LSM infrastructure knows how many xattr slots it should
allocate.
Modify the inode_init_security hook definition, by passing the full
xattr array allocated in security_inode_init_security(), and the current
number of xattr slots in that array filled by LSMs. The first parameter
would allow EVM to access and calculate the HMAC on xattrs supplied by
other LSMs, the second to not leave gaps in the xattr array, when an LSM
requested but did not provide xattrs (e.g. if it is not initialized).
Introduce lsm_get_xattr_slot(), which LSMs can call as many times as the
number specified in the lbs_xattr_count field of the lsm_blob_sizes
structure. During each call, lsm_get_xattr_slot() increments the number of
filled xattrs, so that at the next invocation it returns the next xattr
slot to fill.
Cleanup security_inode_init_security(). Unify the !initxattrs and
initxattrs case by simply not allocating the new_xattrs array in the
former. Update the documentation to reflect the changes, and fix the
description of the xattr name, as it is not allocated anymore.
Adapt both SELinux and Smack to use the new definition of the
inode_init_security hook, and to call lsm_get_xattr_slot() to obtain and
fill the reserved slots in the xattr array.
Move the xattr->name assignment after the xattr->value one, so that it is
done only in case of successful memory allocation.
Finally, change the default return value of the inode_init_security hook
from zero to -EOPNOTSUPP, so that BPF LSM correctly follows the hook
conventions.
Reported-by: Nicolas Bouchinet <nicolas.bouchinet@clip-os.org>
Link: https://lore.kernel.org/linux-integrity/Y1FTSIo+1x+4X0LS@archlinux/
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
[PM: minor comment and variable tweaks, approved by RS]
Signed-off-by: Paul Moore <paul@paul-moore.com>
smack_dentry_create_files_as() determines whether transmuting should occur
based on the label of the parent directory the new inode will be added to,
and not the label of the directory where it is created.
This helps for example to do transmuting on overlayfs, since the latter
first creates the inode in the working directory, and then moves it to the
correct destination.
However, despite smack_dentry_create_files_as() provides the correct label,
smack_inode_init_security() does not know from passed information whether
or not transmuting occurred. Without this information,
smack_inode_init_security() cannot set SMK_INODE_CHANGED in smk_flags,
which will result in the SMACK64TRANSMUTE xattr not being set in
smack_d_instantiate().
Thus, add the smk_transmuted field to the task_smack structure, and set it
in smack_dentry_create_files_as() to smk_task if transmuting occurred. If
smk_task is equal to smk_transmuted in smack_inode_init_security(), act as
if transmuting was successful but without taking the label from the parent
directory (the inode label was already set correctly from the current
credentials in smack_inode_alloc_security()).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Enhance smack_inode_getsecurity() to retrieve the value for
SMACK64TRANSMUTE from the inode security blob, similarly to SMACK64.
This helps to display accurate values in the situation where the security
labels come from mount options and not from xattrs.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Pull smack updates from Casey Schaufler:
"There are two changes, one small and one more substantial:
- Remove of an unnecessary cast
- The mount option processing introduced with the mount rework makes
copies of mount option values. There is no good reason to make
copies of Smack labels, as they are maintained on a list and never
removed.
The code now uses pointers to entries on the list, reducing
processing time and memory use"
* tag 'Smack-for-6.4' of https://github.com/cschaufler/smack-next:
Smack: Improve mount process memory use
smack_lsm: remove unnecessary type casting
The existing mount processing code in Smack makes many unnecessary
copies of Smack labels. Because Smack labels never go away once
imported it is safe to use pointers to them rather than copies.
Replace the use of copies of label names to pointers to the global
label list entries.
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
After working with the larger SELinux-based distros for several
years, we're finally at a place where we can disable the SELinux
runtime disable functionality. The existing kernel deprecation
notice explains the functionality and why we want to remove it:
The selinuxfs "disable" node allows SELinux to be disabled at
runtime prior to a policy being loaded into the kernel. If
disabled via this mechanism, SELinux will remain disabled until
the system is rebooted.
The preferred method of disabling SELinux is via the "selinux=0"
boot parameter, but the selinuxfs "disable" node was created to
make it easier for systems with primitive bootloaders that did not
allow for easy modification of the kernel command line.
Unfortunately, allowing for SELinux to be disabled at runtime makes
it difficult to secure the kernel's LSM hooks using the
"__ro_after_init" feature.
It is that last sentence, mentioning the '__ro_after_init' hardening,
which is the real motivation for this change, and if you look at the
diffstat you'll see that the impact of this patch reaches across all
the different LSMs, helping prevent tampering at the LSM hook level.
From a SELinux perspective, it is important to note that if you
continue to disable SELinux via "/etc/selinux/config" it may appear
that SELinux is disabled, but it is simply in an uninitialized state.
If you load a policy with `load_policy -i`, you will see SELinux
come alive just as if you had loaded the policy during early-boot.
It is also worth noting that the "/sys/fs/selinux/disable" file is
always writable now, regardless of the Kconfig settings, but writing
to the file has no effect on the system, other than to display an
error on the console if a non-zero/true value is written.
Finally, in the several years where we have been working on
deprecating this functionality, there has only been one instance of
someone mentioning any user visible breakage. In this particular
case it was an individual's kernel test system, and the workaround
documented in the deprecation notice ("selinux=0" on the kernel
command line) resolved the issue without problem.
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Remove unnecessary type casting.
The type of inode variable is struct inode *, so no type casting required.
Signed-off-by: XU pengfei <xupengfei@nfschina.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Roberto Sassu
Linus Torvalds
Alfred Piccioni
Kent Overstreet
Pavel Begunkov
Paul Moore
Casey Schaufler
David Howells
Dan Carpenter
Tóth János
XU pengfei