Pull lsm updates from Paul Moore:
- Promote IMA/EVM to a proper LSM
This is the bulk of the diffstat, and the source of all the changes
in the VFS code. Prior to the start of the LSM stacking work it was
important that IMA/EVM were separate from the rest of the LSMs,
complete with their own hooks, infrastructure, etc. as it was the
only way to enable IMA/EVM at the same time as a LSM.
However, now that the bulk of the LSM infrastructure supports
multiple simultaneous LSMs, we can simplify things greatly by
bringing IMA/EVM into the LSM infrastructure as proper LSMs. This is
something I've wanted to see happen for quite some time and Roberto
was kind enough to put in the work to make it happen.
- Use the LSM hook default values to simplify the call_int_hook() macro
Previously the call_int_hook() macro required callers to supply a
default return value, despite a default value being specified when
the LSM hook was defined.
This simplifies the macro by using the defined default return value
which makes life easier for callers and should also reduce the number
of return value bugs in the future (we've had a few pop up recently,
hence this work).
- Use the KMEM_CACHE() macro instead of kmem_cache_create()
The guidance appears to be to use the KMEM_CACHE() macro when
possible and there is no reason why we can't use the macro, so let's
use it.
- Fix a number of comment typos in the LSM hook comment blocks
Not much to say here, we fixed some questionable grammar decisions in
the LSM hook comment blocks.
* tag 'lsm-pr-20240312' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/lsm: (28 commits)
cred: Use KMEM_CACHE() instead of kmem_cache_create()
lsm: use default hook return value in call_int_hook()
lsm: fix typos in security/security.c comment headers
integrity: Remove LSM
ima: Make it independent from 'integrity' LSM
evm: Make it independent from 'integrity' LSM
evm: Move to LSM infrastructure
ima: Move IMA-Appraisal to LSM infrastructure
ima: Move to LSM infrastructure
integrity: Move integrity_kernel_module_request() to IMA
security: Introduce key_post_create_or_update hook
security: Introduce inode_post_remove_acl hook
security: Introduce inode_post_set_acl hook
security: Introduce inode_post_create_tmpfile hook
security: Introduce path_post_mknod hook
security: Introduce file_release hook
security: Introduce file_post_open hook
security: Introduce inode_post_removexattr hook
security: Introduce inode_post_setattr hook
security: Align inode_setattr hook definition with EVM
...
Currently when the kernel fails to add a cert to the .machine keyring,
it will throw an error immediately in the function integrity_add_key.
Since the kernel will try adding to the .platform keyring next or throw
an error (in the caller of integrity_add_key i.e. add_to_machine_keyring),
so there is no need to throw an error immediately in integrity_add_key.
Reported-by: itrymybest80@protonmail.com
Closes: https://bugzilla.redhat.com/show_bug.cgi?id=2239331
Fixes: d19967764b ("integrity: Introduce a Linux keyring called machine")
Reviewed-by: Eric Snowberg <eric.snowberg@oracle.com>
Signed-off-by: Coiby Xu <coxu@redhat.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Since now IMA and EVM use their own integrity metadata, it is safe to
remove the 'integrity' LSM, with its management of integrity metadata.
Keep the iint.c file only for loading IMA and EVM keys at boot, and for
creating the integrity directory in securityfs (we need to keep it for
retrocompatibility reasons).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA
own integrity metadata (ima_iint_cache structure, with IMA-specific fields
from the integrity_iint_cache structure), and by managing it directly from
the 'ima' LSM.
Create ima_iint.c and introduce the same integrity metadata management
functions found in iint.c (renamed with ima_). However, instead of putting
metadata in an rbtree, reserve space from IMA in the inode security blob
for a pointer, and introduce the ima_inode_set_iint()/ima_inode_get_iint()
primitives to store/retrieve that pointer. This improves search time from
logarithmic to constant.
Consequently, don't include the inode pointer as field in the
ima_iint_cache structure, since the association with the inode is clear.
Since the inode field is missing in ima_iint_cache, pass the extra inode
parameter to ima_get_verity_digest().
Prefer storing the pointer instead of the entire ima_iint_cache structure,
to avoid too much memory pressure. Use the same mechanism as before, a
cache named ima_iint_cache (renamed from iint_cache), to quickly allocate
a new ima_iint_cache structure when requested by the IMA policy.
Create the new ima_iint_cache in ima_iintcache_init(),
called by init_ima_lsm(), during the initialization of the 'ima' LSM. And,
register ima_inode_free_security() to free the ima_iint_cache structure, if
exists.
Replace integrity_iint_cache with ima_iint_cache in various places of the
IMA code. Also, replace integrity_inode_get() and integrity_iint_find(),
respectively with ima_inode_get() and ima_iint_find().
Finally, move the remaining IMA-specific flags
to security/integrity/ima/ima.h, since they are now unnecessary in the
common integrity layer.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Define a new structure for EVM-specific metadata, called evm_iint_cache,
and embed it in the inode security blob. Introduce evm_iint_inode() to
retrieve metadata, and register evm_inode_alloc_security() for the
inode_alloc_security LSM hook, to initialize the structure (before
splitting metadata, this task was done by iint_init_always()).
Keep the non-NULL checks after calling evm_iint_inode() except in
evm_inode_alloc_security(), to take into account inodes for which
security_inode_alloc() was not called. When using shared metadata,
obtaining a NULL pointer from integrity_iint_find() meant that the file
wasn't in the IMA policy. Now, because IMA and EVM use disjoint metadata,
the EVM status has to be stored for every inode regardless of the IMA
policy.
Given that from now on EVM relies on its own metadata, remove the iint
parameter from evm_verifyxattr(). Also, directly retrieve the iint in
evm_verify_hmac(), called by both evm_verifyxattr() and
evm_verify_current_integrity(), since now there is no performance penalty
in retrieving EVM metadata (constant time).
Replicate the management of the IMA_NEW_FILE flag, by introducing
evm_post_path_mknod() and evm_file_release() to respectively set and clear
the newly introduced flag EVM_NEW_FILE, at the same time IMA does. Like for
IMA, select CONFIG_SECURITY_PATH when EVM is enabled, to ensure that files
are marked as new.
Unlike ima_post_path_mknod(), evm_post_path_mknod() cannot check if a file
must be appraised. Thus, it marks all affected files. Also, it does not
clear EVM_NEW_FILE depending on i_version, but that is not a problem
because IMA_NEW_FILE is always cleared when set in ima_check_last_writer().
Move the EVM-specific flag EVM_IMMUTABLE_DIGSIG to
security/integrity/evm/evm.h, since that definition is now unnecessary in
the common integrity layer.
Finally, switch to the LSM reservation mechanism for the EVM xattr, and
consequently decrement by one the number of xattrs to allocate in
security_inode_init_security().
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
As for IMA, move hardcoded EVM function calls from various places in the
kernel to the LSM infrastructure, by introducing a new LSM named 'evm'
(last and always enabled like 'ima'). The order in the Makefile ensures
that 'evm' hooks are executed after 'ima' ones.
Make EVM functions as static (except for evm_inode_init_security(), which
is exported), and register them as hook implementations in init_evm_lsm().
Also move the inline functions evm_inode_remove_acl(),
evm_inode_post_remove_acl(), and evm_inode_post_set_acl() from the public
evm.h header to evm_main.c.
Unlike before (see commit to move IMA to the LSM infrastructure),
evm_inode_post_setattr(), evm_inode_post_set_acl(),
evm_inode_post_remove_acl(), and evm_inode_post_removexattr() are not
executed for private inodes.
Finally, add the LSM_ID_EVM case in lsm_list_modules_test.c
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
A few additional IMA hooks are needed to reset the cached appraisal
status, causing the file's integrity to be re-evaluated on next access.
Register these IMA-appraisal only functions separately from the rest of IMA
functions, as appraisal is a separate feature not necessarily enabled in
the kernel configuration.
Reuse the same approach as for other IMA functions, move hardcoded calls
from various places in the kernel to the LSM infrastructure. Declare the
functions as static and register them as hook implementations in
init_ima_appraise_lsm(), called by init_ima_lsm().
Also move the inline function ima_inode_remove_acl() from the public ima.h
header to ima_appraise.c.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Move hardcoded IMA function calls (not appraisal-specific functions) from
various places in the kernel to the LSM infrastructure, by introducing a
new LSM named 'ima' (at the end of the LSM list and always enabled like
'integrity').
Having IMA before EVM in the Makefile is sufficient to preserve the
relative order of the new 'ima' LSM in respect to the upcoming 'evm' LSM,
and thus the order of IMA and EVM function calls as when they were
hardcoded.
Make moved functions as static (except ima_post_key_create_or_update(),
which is not in ima_main.c), and register them as implementation of the
respective hooks in the new function init_ima_lsm().
Select CONFIG_SECURITY_PATH, to ensure that the path-based LSM hook
path_post_mknod is always available and ima_post_path_mknod() is always
executed to mark files as new, as before the move.
A slight difference is that IMA and EVM functions registered for the
inode_post_setattr, inode_post_removexattr, path_post_mknod,
inode_post_create_tmpfile, inode_post_set_acl and inode_post_remove_acl
won't be executed for private inodes. Since those inodes are supposed to be
fs-internal, they should not be of interest to IMA or EVM. The S_PRIVATE
flag is used for anonymous inodes, hugetlbfs, reiserfs xattrs, XFS scrub
and kernel-internal tmpfs files.
Conditionally register ima_post_key_create_or_update() if
CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Also, conditionally register
ima_kernel_module_request() if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled.
Finally, add the LSM_ID_IMA case in lsm_list_modules_test.c.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Acked-by: Chuck Lever <chuck.lever@oracle.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
In preparation for removing the 'integrity' LSM, move
integrity_kernel_module_request() to IMA, and rename it to
ima_kernel_module_request(). Rewrite the function documentation, to explain
better what the problem is.
Compile it conditionally if CONFIG_INTEGRITY_ASYMMETRIC_KEYS is enabled,
and call it from security.c (removed afterwards with the move of IMA to the
LSM infrastructure).
Adding this hook cannot be avoided, since IMA has no control on the flags
passed to crypto_alloc_sig() in public_key_verify_signature(), and thus
cannot pass CRYPTO_NOLOAD, which solved the problem for EVM hashing with
commit e2861fa716 ("evm: Don't deadlock if a crypto algorithm is
unavailable").
EVM alone does not need to implement this hook, first because there is no
mutex to deadlock, and second because even if it had it, there should be a
recursive call. However, since verification from EVM can be initiated only
by setting inode metadata, deadlock would occur if modprobe would do the
same while loading a kernel module (which is unlikely).
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Stefan Berger <stefanb@linux.ibm.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Pull integrity updates from Mimi Zohar:
- Add a new IMA/EVM maintainer and reviewer
- Disable EVM on overlayfs
The EVM HMAC and the original file signatures contain filesystem
specific metadata (e.g. i_ino, i_generation and s_uuid), preventing
the security.evm xattr from directly being copied up to the overlay.
Further before calculating and writing out the overlay file's EVM
HMAC, EVM must first verify the existing backing file's
'security.evm' value.
For now until a solution is developed, disable EVM on overlayfs.
- One bug fix and two cleanups
* tag 'integrity-v6.8' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
overlay: disable EVM
evm: add support to disable EVM on unsupported filesystems
evm: don't copy up 'security.evm' xattr
MAINTAINERS: Add Eric Snowberg as a reviewer to IMA
MAINTAINERS: Add Roberto Sassu as co-maintainer to IMA and EVM
KEYS: encrypted: Add check for strsep
ima: Remove EXPERIMENTAL from Kconfig
ima: Reword IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY
Pull non-MM updates from Andrew Morton:
"Quite a lot of kexec work this time around. Many singleton patches in
many places. The notable patch series are:
- nilfs2 folio conversion from Matthew Wilcox in 'nilfs2: Folio
conversions for file paths'.
- Additional nilfs2 folio conversion from Ryusuke Konishi in 'nilfs2:
Folio conversions for directory paths'.
- IA64 remnant removal in Heiko Carstens's 'Remove unused code after
IA-64 removal'.
- Arnd Bergmann has enabled the -Wmissing-prototypes warning
everywhere in 'Treewide: enable -Wmissing-prototypes'. This had
some followup fixes:
- Nathan Chancellor has cleaned up the hexagon build in the series
'hexagon: Fix up instances of -Wmissing-prototypes'.
- Nathan also addressed some s390 warnings in 's390: A couple of
fixes for -Wmissing-prototypes'.
- Arnd Bergmann addresses the same warnings for MIPS in his series
'mips: address -Wmissing-prototypes warnings'.
- Baoquan He has made kexec_file operate in a top-down-fitting manner
similar to kexec_load in the series 'kexec_file: Load kernel at top
of system RAM if required'
- Baoquan He has also added the self-explanatory 'kexec_file: print
out debugging message if required'.
- Some checkstack maintenance work from Tiezhu Yang in the series
'Modify some code about checkstack'.
- Douglas Anderson has disentangled the watchdog code's logging when
multiple reports are occurring simultaneously. The series is
'watchdog: Better handling of concurrent lockups'.
- Yuntao Wang has contributed some maintenance work on the crash code
in 'crash: Some cleanups and fixes'"
* tag 'mm-nonmm-stable-2024-01-09-10-33' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (157 commits)
crash_core: fix and simplify the logic of crash_exclude_mem_range()
x86/crash: use SZ_1M macro instead of hardcoded value
x86/crash: remove the unused image parameter from prepare_elf_headers()
kdump: remove redundant DEFAULT_CRASH_KERNEL_LOW_SIZE
scripts/decode_stacktrace.sh: strip unexpected CR from lines
watchdog: if panicking and we dumped everything, don't re-enable dumping
watchdog/hardlockup: use printk_cpu_sync_get_irqsave() to serialize reporting
watchdog/softlockup: use printk_cpu_sync_get_irqsave() to serialize reporting
watchdog/hardlockup: adopt softlockup logic avoiding double-dumps
kexec_core: fix the assignment to kimage->control_page
x86/kexec: fix incorrect end address passed to kernel_ident_mapping_init()
lib/trace_readwrite.c:: replace asm-generic/io with linux/io
nilfs2: cpfile: fix some kernel-doc warnings
stacktrace: fix kernel-doc typo
scripts/checkstack.pl: fix no space expression between sp and offset
x86/kexec: fix incorrect argument passed to kexec_dprintk()
x86/kexec: use pr_err() instead of kexec_dprintk() when an error occurs
nilfs2: add missing set_freezable() for freezable kthread
kernel: relay: remove relay_file_splice_read dead code, doesn't work
docs: submit-checklist: remove all of "make namespacecheck"
...
Identify EVM unsupported filesystems by defining a new flag
SB_I_EVM_UNSUPPORTED.
Don't verify, write, remove or update 'security.evm' on unsupported
filesystems.
Acked-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The security.evm HMAC and the original file signatures contain
filesystem specific data. As a result, the HMAC and signature
are not the same on the stacked and backing filesystems.
Don't copy up 'security.evm'.
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
When the machine keyring is enabled, it may be used as a trust source
for the .ima keyring. Add a reference to this in
IMA_KEYRINGS_PERMIT_SIGNED_BY_BUILTIN_OR_SECONDARY.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
