lsm: use lsm_prop in security_current_getsecid

Change the security_current_getsecid_subj() and
security_task_getsecid_obj() interfaces to fill in a lsm_prop structure
instead of a u32 secid. Audit

lsm: use lsm_prop in security_current_getsecid

Change the security_current_getsecid_subj() and
security_task_getsecid_obj() interfaces to fill in a lsm_prop structure
instead of a u32 secid. Audit interfaces will need to collect all
possible security data for possible reporting.

Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Casey Schaufler <[email protected]>
[PM: subject line tweak]
Signed-off-by: Paul Moore <[email protected]>

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ima: Move file-change detection variables into new structure

Move all the variables used for file change detection into a structure
that can be used by IMA and EVM. Implement an inline function for

ima: Move file-change detection variables into new structure

Move all the variables used for file change detection into a structure
that can be used by IMA and EVM. Implement an inline function for storing
the identification of an inode and one for detecting changes to an inode
based on this new structure.

Co-developed-by: Mimi Zohar <[email protected]>
Signed-off-by: Stefan Berger <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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integrity: Avoid -Wflex-array-member-not-at-end warnings

-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.

There is currently an object (`hdr)` in

integrity: Avoid -Wflex-array-member-not-at-end warnings

-Wflex-array-member-not-at-end is coming in GCC-14, and we are getting
ready to enable it globally.

There is currently an object (`hdr)` in `struct ima_max_digest_data`
that contains a flexible structure (`struct ima_digest_data`):

struct ima_max_digest_data {
struct ima_digest_data hdr;
u8 digest[HASH_MAX_DIGESTSIZE];
} __packed;

So, in order to avoid ending up with a flexible-array member in the
middle of a struct, we use the `__struct_group()` helper to separate
the flexible array from the rest of the members in the flexible
structure:

struct ima_digest_data {
__struct_group(ima_digest_data_hdr, hdr, __packed,

... the rest of the members

);
u8 digest[];
} __packed;

And similarly for `struct evm_ima_xattr_data`.

With the change described above, we can now declare an object of the
type of the tagged `struct ima_digest_data_hdr`, without embedding the
flexible array in the middle of another struct:

struct ima_max_digest_data {
struct ima_digest_data_hdr hdr;
u8 digest[HASH_MAX_DIGESTSIZE];
} __packed;

And similarly for `struct evm_digest` and `struct evm_xattr`.

We also use `container_of()` whenever we need to retrieve a pointer to
the flexible structure.

So, with these changes, fix the following warnings:

security/integrity/evm/evm.h:64:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/evm/../integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/evm/../integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/ima/../integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/ima/../integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/platform_certs/../integrity.h:40:35: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]
security/integrity/platform_certs/../integrity.h:68:32: warning: structure containing a flexible array member is not at the end of another structure [-Wflex-array-member-not-at-end]

Link: https://github.com/KSPP/linux/issues/202
Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Fix use-after-free on a dentry's dname.name

->d_name.name can change on rename and the earlier value can be freed;
there are conditions sufficient to stabilize it (->d_lock on dentry,
->d_lock

ima: Fix use-after-free on a dentry's dname.name

->d_name.name can change on rename and the earlier value can be freed;
there are conditions sufficient to stabilize it (->d_lock on dentry,
->d_lock on its parent, ->i_rwsem exclusive on the parent's inode,
rename_lock), but none of those are met at any of the sites. Take a stable
snapshot of the name instead.

Link: https://lore.kernel.org/all/20240202182732.GE2087318@ZenIV/
Signed-off-by: Al Viro <[email protected]>
Signed-off-by: Stefan Berger <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Make it independent from 'integrity' LSM

Make the 'ima' LSM independent from the 'integrity' LSM by introducing IMA
own integrity metadata (ima_iint_cache structure, with IMA-specific fields
fr

ima: Make it independent from 'integrity' LSM

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 <[email protected]>
Reviewed-by: Casey Schaufler <[email protected]>
Reviewed-by: Stefan Berger <[email protected]>
Reviewed-by: Mimi Zohar <[email protected]>
Acked-by: Mimi Zohar <[email protected]>
Signed-off-by: Paul Moore <[email protected]>

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ima: detect changes to the backing overlay file

Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for
IMA") forced signature re-evaulation on every file access.

Instead of always re-e

ima: detect changes to the backing overlay file

Commit 18b44bc5a672 ("ovl: Always reevaluate the file signature for
IMA") forced signature re-evaulation on every file access.

Instead of always re-evaluating the file's integrity, detect a change
to the backing file, by comparing the cached file metadata with the
backing file's metadata. Verifying just the i_version has not changed
is insufficient. In addition save and compare the i_ino and s_dev
as well.

Reviewed-by: Amir Goldstein <[email protected]>
Tested-by: Eric Snowberg <[email protected]>
Tested-by: Raul E Rangel <[email protected]>
Cc: [email protected]
Signed-off-by: Mimi Zohar <[email protected]>

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fsverity: rework fsverity_get_digest() again

Address several issues with the calling convention and documentation of
fsverity_get_digest():

- Make it provide the hash algorithm as either a FS_VERIT

fsverity: rework fsverity_get_digest() again

Address several issues with the calling convention and documentation of
fsverity_get_digest():

- Make it provide the hash algorithm as either a FS_VERITY_HASH_ALG_*
value or HASH_ALGO_* value, at the caller's choice, rather than only a
HASH_ALGO_* value as it did before. This allows callers to work with
the fsverity native algorithm numbers if they want to. HASH_ALGO_* is
what IMA uses, but other users (e.g. overlayfs) should use
FS_VERITY_HASH_ALG_* to match fsverity-utils and the fsverity UAPI.

- Make it return the digest size so that it doesn't need to be looked up
separately. Use the return value for this, since 0 works nicely for
the "file doesn't have fsverity enabled" case. This also makes it
clear that no other errors are possible.

- Rename the 'digest' parameter to 'raw_digest' and clearly document
that it is only useful in combination with the algorithm ID. This
hopefully clears up a point of confusion.

- Export it to modules, since overlayfs will need it for checking the
fsverity digests of lowerdata files
(https://lore.kernel.org/r/dd294a44e8f401e6b5140029d8355f88748cd8fd.1686565330.git.alexl@redhat.com).

Acked-by: Mimi Zohar <[email protected]> # for the IMA piece
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Eric Biggers <[email protected]>

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IMA: use vfs_getattr_nosec to get the i_version

IMA currently accesses the i_version out of the inode directly when it
does a measurement. This is fine for most simple filesystems, but can be
proble

IMA: use vfs_getattr_nosec to get the i_version

IMA currently accesses the i_version out of the inode directly when it
does a measurement. This is fine for most simple filesystems, but can be
problematic with more complex setups (e.g. overlayfs).

Make IMA instead call vfs_getattr_nosec to get this info. This allows
the filesystem to determine whether and how to report the i_version, and
should allow IMA to work properly with a broader class of filesystems in
the future.

Reported-and-Tested-by: Stefan Berger <[email protected]>
Reviewed-by: Christian Brauner <[email protected]>
Signed-off-by: Jeff Layton <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Introduce MMAP_CHECK_REQPROT hook

Commit 98de59bfe4b2f ("take calculation of final prot in
security_mmap_file() into a helper") caused ima_file_mmap() to receive the
protections requested by th

ima: Introduce MMAP_CHECK_REQPROT hook

Commit 98de59bfe4b2f ("take calculation of final prot in
security_mmap_file() into a helper") caused ima_file_mmap() to receive the
protections requested by the application and not those applied by the
kernel.

After restoring the original MMAP_CHECK behavior, existing attestation
servers might be broken due to not being ready to handle new entries
(previously missing) in the IMA measurement list.

Restore the original correct MMAP_CHECK behavior, instead of keeping the
current buggy one and introducing a new hook with the correct behavior.
Otherwise, there would have been the risk of IMA users not noticing the
problem at all, as they would actively have to update the IMA policy, to
switch to the correct behavior.

Also, introduce the new MMAP_CHECK_REQPROT hook to keep the current
behavior, so that IMA users could easily fix a broken attestation server,
although this approach is discouraged due to potentially missing
measurements.

Signed-off-by: Roberto Sassu <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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fs: port xattr to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conver

fs: port xattr to mnt_idmap

Convert to struct mnt_idmap.

Last cycle we merged the necessary infrastructure in
256c8aed2b42 ("fs: introduce dedicated idmap type for mounts").
This is just the conversion to struct mnt_idmap.

Currently we still pass around the plain namespace that was attached to a
mount. This is in general pretty convenient but it makes it easy to
conflate namespaces that are relevant on the filesystem with namespaces
that are relevent on the mount level. Especially for non-vfs developers
without detailed knowledge in this area this can be a potential source for
bugs.

Once the conversion to struct mnt_idmap is done all helpers down to the
really low-level helpers will take a struct mnt_idmap argument instead of
two namespace arguments. This way it becomes impossible to conflate the two
eliminating the possibility of any bugs. All of the vfs and all filesystems
only operate on struct mnt_idmap.

Acked-by: Dave Chinner <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Signed-off-by: Christian Brauner (Microsoft) <[email protected]>

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ima: fix error handling logic when file measurement failed

Restore the error handling logic so that when file measurement fails,
the respective iint entry is not left with the digest data being
popu

ima: fix error handling logic when file measurement failed

Restore the error handling logic so that when file measurement fails,
the respective iint entry is not left with the digest data being
populated with zeroes.

Fixes: 54f03916fb89 ("ima: permit fsverity's file digests in the IMA measurement list")
Cc: [email protected] # 5.19
Signed-off-by: Matt Bobrowski <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: permit fsverity's file digests in the IMA measurement list

Permit fsverity's file digest (a hash of struct fsverity_descriptor) to
be included in the IMA measurement list, based on the new meas

ima: permit fsverity's file digests in the IMA measurement list

Permit fsverity's file digest (a hash of struct fsverity_descriptor) to
be included in the IMA measurement list, based on the new measurement
policy rule 'digest_type=verity' option.

To differentiate between a regular IMA file hash from an fsverity's
file digest, use the new d-ngv2 format field included in the ima-ngv2
template.

The following policy rule requires fsverity file digests and specifies
the new 'ima-ngv2' template, which contains the new 'd-ngv2' field. The
policy rule may be constrained, for example based on a fsuuid or LSM
label.

measure func=FILE_CHECK digest_type=verity template=ima-ngv2

Acked-by: Stefan Berger <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: define ima_max_digest_data struct without a flexible array variable

To support larger hash digests in the 'iint' cache, instead of defining
the 'digest' field as the maximum digest size, the 'd

ima: define ima_max_digest_data struct without a flexible array variable

To support larger hash digests in the 'iint' cache, instead of defining
the 'digest' field as the maximum digest size, the 'digest' field was
defined as a flexible array variable. The "ima_digest_data" struct was
wrapped inside a local structure with the maximum digest size. But
before adding the record to the iint cache, memory for the exact digest
size was dynamically allocated.

The original reason for defining the 'digest' field as a flexible array
variable is still valid for the 'iint' cache use case. Instead of
wrapping the 'ima_digest_data' struct in a local structure define
'ima_max_digest_data' struct.

Reviewed-by: Stefan Berger <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Fix trivial typos in the comments

There are a few minor typos in the comments. Fix these.

Signed-off-by: Austin Kim <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

ima: Use strscpy instead of strlcpy

strlcpy is deprecated, use its safer replacement.

Signed-off-by: Petr Vorel <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

IMA: add support to restrict the hash algorithms used for file appraisal

The kernel accepts any hash algorithm as a value for the security.ima
xattr. Users may wish to restrict the accepted algorith

IMA: add support to restrict the hash algorithms used for file appraisal

The kernel accepts any hash algorithm as a value for the security.ima
xattr. Users may wish to restrict the accepted algorithms to only
support strong cryptographic ones.

Provide the plumbing to restrict the permitted set of hash algorithms
used for verifying file hashes and signatures stored in security.ima
xattr.

Signed-off-by: THOBY Simon <[email protected]>
Reviewed-by: Lakshmi Ramasubramanian <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: handle idmapped mounts

IMA does sometimes access the inode's i_uid and compares it against the
rules' fowner. Enable IMA to handle idmapped mounts by passing down the
mount's user namespace. We

ima: handle idmapped mounts

IMA does sometimes access the inode's i_uid and compares it against the
rules' fowner. Enable IMA to handle idmapped mounts by passing down the
mount's user namespace. We simply make use of the helpers we introduced
before. If the initial user namespace is passed nothing changes so
non-idmapped mounts will see identical behavior as before.

Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Christian Brauner <[email protected]>

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IMA: define a hook to measure kernel integrity critical data

IMA provides capabilities to measure file and buffer data. However,
various data structures, policies, and states stored in kernel memor

IMA: define a hook to measure kernel integrity critical data

IMA provides capabilities to measure file and buffer data. However,
various data structures, policies, and states stored in kernel memory
also impact the integrity of the system. Several kernel subsystems
contain such integrity critical data. These kernel subsystems help
protect the integrity of the system. Currently, IMA does not provide a
generic function for measuring kernel integrity critical data.

Define ima_measure_critical_data, a new IMA hook, to measure kernel
integrity critical data.

Signed-off-by: Tushar Sugandhi <[email protected]>
Reviewed-by: Tyler Hicks <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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IMA: generalize keyring specific measurement constructs

IMA functions such as ima_match_keyring(), process_buffer_measurement(),
ima_match_policy() etc. handle data specific to keyrings. Currently

IMA: generalize keyring specific measurement constructs

IMA functions such as ima_match_keyring(), process_buffer_measurement(),
ima_match_policy() etc. handle data specific to keyrings. Currently,
these constructs are not generic to handle any func specific data.
This makes it harder to extend them without code duplication.

Refactor the keyring specific measurement constructs to be generic and
reusable in other measurement scenarios.

Signed-off-by: Tushar Sugandhi <[email protected]>
Reviewed-by: Tyler Hicks <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Support additional conditionals in the KEXEC_CMDLINE hook function

Take the properties of the kexec kernel's inode and the current task
ownership into consideration when matching a KEXEC_CMDLIN

ima: Support additional conditionals in the KEXEC_CMDLINE hook function

Take the properties of the kexec kernel's inode and the current task
ownership into consideration when matching a KEXEC_CMDLINE operation to
the rules in the IMA policy. This allows for some uniformity when
writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK,
and KEXEC_CMDLINE operations.

Prior to this patch, it was not possible to write a set of rules like
this:

dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t
dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t
dont_measure func=KEXEC_CMDLINE obj_type=foo_t
measure func=KEXEC_KERNEL_CHECK
measure func=KEXEC_INITRAMFS_CHECK
measure func=KEXEC_CMDLINE

The inode information associated with the kernel being loaded by a
kexec_kernel_load(2) syscall can now be included in the decision to
measure or not

Additonally, the uid, euid, and subj_* conditionals can also now be
used in KEXEC_CMDLINE rules. There was no technical reason as to why
those conditionals weren't being considered previously other than
ima_match_rules() didn't have a valid inode to use so it immediately
bailed out for KEXEC_CMDLINE operations rather than going through the
full list of conditional comparisons.

Signed-off-by: Tyler Hicks <[email protected]>
Cc: Eric Biederman <[email protected]>
Cc: [email protected]
Reviewed-by: Lakshmi Ramasubramanian <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Directly free *entry in ima_alloc_init_template() if digests is NULL

To support multiple template digests, the static array entry->digest has
been replaced with a dynamically allocated array in

ima: Directly free *entry in ima_alloc_init_template() if digests is NULL

To support multiple template digests, the static array entry->digest has
been replaced with a dynamically allocated array in commit aa724fe18a8a
("ima: Switch to dynamically allocated buffer for template digests"). The
array is allocated in ima_alloc_init_template() and if the returned pointer
is NULL, ima_free_template_entry() is called.

However, (*entry)->template_desc is not yet initialized while it is used by
ima_free_template_entry(). This patch fixes the issue by directly freeing
*entry without calling ima_free_template_entry().

Fixes: aa724fe18a8a ("ima: Switch to dynamically allocated buffer for template digests")
Reported-by: [email protected]
Signed-off-by: Roberto Sassu <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Switch to dynamically allocated buffer for template digests

This patch dynamically allocates the array of tpm_digest structures in
ima_alloc_init_template() and ima_restore_template_data(). The

ima: Switch to dynamically allocated buffer for template digests

This patch dynamically allocates the array of tpm_digest structures in
ima_alloc_init_template() and ima_restore_template_data(). The size of the
array is equal to the number of PCR banks plus ima_extra_slots, to make
room for SHA1 and the IMA default hash algorithm, when PCR banks with those
algorithms are not allocated.

Calculating the SHA1 digest is mandatory, as SHA1 still remains the default
hash algorithm for the measurement list. When IMA will support the Crypto
Agile format, remaining digests will be also provided.

The position in the measurement entry array of the SHA1 digest is stored in
the ima_sha1_idx global variable and is determined at IMA initialization
time.

Signed-off-by: Roberto Sassu <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: Store template digest directly in ima_template_entry

In preparation for the patch that calculates a digest for each allocated
PCR bank, this patch passes to ima_calc_field_array_hash() the
ima_

ima: Store template digest directly in ima_template_entry

In preparation for the patch that calculates a digest for each allocated
PCR bank, this patch passes to ima_calc_field_array_hash() the
ima_template_entry structure, so that digests can be directly stored in
that structure instead of ima_digest_data.

Signed-off-by: Roberto Sassu <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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IMA: Add support to limit measuring keys

Limit measuring keys to those keys being loaded onto a given set of
keyrings only and when the user id (uid) matches if uid is specified
in the policy.

This

IMA: Add support to limit measuring keys

Limit measuring keys to those keys being loaded onto a given set of
keyrings only and when the user id (uid) matches if uid is specified
in the policy.

This patch defines a new IMA policy option namely "keyrings=" that
can be used to specify a set of keyrings. If this option is specified
in the policy for "measure func=KEY_CHECK" then only the keys
loaded onto a keyring given in the "keyrings=" option are measured.

If uid is specified in the policy then the key is measured only if
the current user id matches the one specified in the policy.

Added a new parameter namely "keyring" (name of the keyring) to
process_buffer_measurement(). The keyring name is passed to
ima_get_action() to determine the required action.
ima_match_rules() is updated to check keyring in the policy, if
specified, for KEY_CHECK function.

Signed-off-by: Lakshmi Ramasubramanian <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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ima: ima_api: Use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory

ima: ima_api: Use struct_size() in kzalloc()

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct ima_template_entry {
...
struct ima_field_data template_data[0]; /* template related data */
};

instance = kzalloc(sizeof(struct ima_template_entry) + count * sizeof(struct ima_field_data), GFP_NOFS);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kzalloc(struct_size(instance, entry, count), GFP_NOFS);

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <[email protected]>
Signed-off-by: Mimi Zohar <[email protected]>

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