The functions defined in "arch/powerpc/kexec/ima.c" handle setting up
and freeing the resources required to carry over the IMA measurement
list from the current kernel to the next kernel across kexec system call.
These functions do not have architecture specific code, but are
currently limited to powerpc.
Move remove_ima_buffer() and setup_ima_buffer() calls into
of_kexec_alloc_and_setup_fdt() defined in "drivers/of/kexec.c".
Move the remaining architecture independent functions from
"arch/powerpc/kexec/ima.c" to "drivers/of/kexec.c".
Delete "arch/powerpc/kexec/ima.c" and "arch/powerpc/include/asm/ima.h".
Remove references to the deleted files and functions in powerpc and
in ima.
Co-developed-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Prakhar Srivastava <prsriva@linux.microsoft.com>
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Tested-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20210221174930.27324-11-nramas@linux.microsoft.com
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Merge tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux
Pull idmapped mounts from Christian Brauner:
"This introduces idmapped mounts which has been in the making for some
time. Simply put, different mounts can expose the same file or
directory with different ownership. This initial implementation comes
with ports for fat, ext4 and with Christoph's port for xfs with more
filesystems being actively worked on by independent people and
maintainers.
Idmapping mounts handle a wide range of long standing use-cases. Here
are just a few:
- Idmapped mounts make it possible to easily share files between
multiple users or multiple machines especially in complex
scenarios. For example, idmapped mounts will be used in the
implementation of portable home directories in
systemd-homed.service(8) where they allow users to move their home
directory to an external storage device and use it on multiple
computers where they are assigned different uids and gids. This
effectively makes it possible to assign random uids and gids at
login time.
- It is possible to share files from the host with unprivileged
containers without having to change ownership permanently through
chown(2).
- It is possible to idmap a container's rootfs and without having to
mangle every file. For example, Chromebooks use it to share the
user's Download folder with their unprivileged containers in their
Linux subsystem.
- It is possible to share files between containers with
non-overlapping idmappings.
- Filesystem that lack a proper concept of ownership such as fat can
use idmapped mounts to implement discretionary access (DAC)
permission checking.
- They allow users to efficiently changing ownership on a per-mount
basis without having to (recursively) chown(2) all files. In
contrast to chown (2) changing ownership of large sets of files is
instantenous with idmapped mounts. This is especially useful when
ownership of a whole root filesystem of a virtual machine or
container is changed. With idmapped mounts a single syscall
mount_setattr syscall will be sufficient to change the ownership of
all files.
- Idmapped mounts always take the current ownership into account as
idmappings specify what a given uid or gid is supposed to be mapped
to. This contrasts with the chown(2) syscall which cannot by itself
take the current ownership of the files it changes into account. It
simply changes the ownership to the specified uid and gid. This is
especially problematic when recursively chown(2)ing a large set of
files which is commong with the aforementioned portable home
directory and container and vm scenario.
- Idmapped mounts allow to change ownership locally, restricting it
to specific mounts, and temporarily as the ownership changes only
apply as long as the mount exists.
Several userspace projects have either already put up patches and
pull-requests for this feature or will do so should you decide to pull
this:
- systemd: In a wide variety of scenarios but especially right away
in their implementation of portable home directories.
https://systemd.io/HOME_DIRECTORY/
- container runtimes: containerd, runC, LXD:To share data between
host and unprivileged containers, unprivileged and privileged
containers, etc. The pull request for idmapped mounts support in
containerd, the default Kubernetes runtime is already up for quite
a while now: https://github.com/containerd/containerd/pull/4734
- The virtio-fs developers and several users have expressed interest
in using this feature with virtual machines once virtio-fs is
ported.
- ChromeOS: Sharing host-directories with unprivileged containers.
I've tightly synced with all those projects and all of those listed
here have also expressed their need/desire for this feature on the
mailing list. For more info on how people use this there's a bunch of
talks about this too. Here's just two recent ones:
https://www.cncf.io/wp-content/uploads/2020/12/Rootless-Containers-in-Gitpod.pdfhttps://fosdem.org/2021/schedule/event/containers_idmap/
This comes with an extensive xfstests suite covering both ext4 and
xfs:
https://git.kernel.org/brauner/xfstests-dev/h/idmapped_mounts
It covers truncation, creation, opening, xattrs, vfscaps, setid
execution, setgid inheritance and more both with idmapped and
non-idmapped mounts. It already helped to discover an unrelated xfs
setgid inheritance bug which has since been fixed in mainline. It will
be sent for inclusion with the xfstests project should you decide to
merge this.
In order to support per-mount idmappings vfsmounts are marked with
user namespaces. The idmapping of the user namespace will be used to
map the ids of vfs objects when they are accessed through that mount.
By default all vfsmounts are marked with the initial user namespace.
The initial user namespace is used to indicate that a mount is not
idmapped. All operations behave as before and this is verified in the
testsuite.
Based on prior discussions we want to attach the whole user namespace
and not just a dedicated idmapping struct. This allows us to reuse all
the helpers that already exist for dealing with idmappings instead of
introducing a whole new range of helpers. In addition, if we decide in
the future that we are confident enough to enable unprivileged users
to setup idmapped mounts the permission checking can take into account
whether the caller is privileged in the user namespace the mount is
currently marked with.
The user namespace the mount will be marked with can be specified by
passing a file descriptor refering to the user namespace as an
argument to the new mount_setattr() syscall together with the new
MOUNT_ATTR_IDMAP flag. The system call follows the openat2() pattern
of extensibility.
The following conditions must be met in order to create an idmapped
mount:
- The caller must currently have the CAP_SYS_ADMIN capability in the
user namespace the underlying filesystem has been mounted in.
- The underlying filesystem must support idmapped mounts.
- The mount must not already be idmapped. This also implies that the
idmapping of a mount cannot be altered once it has been idmapped.
- The mount must be a detached/anonymous mount, i.e. it must have
been created by calling open_tree() with the OPEN_TREE_CLONE flag
and it must not already have been visible in the filesystem.
The last two points guarantee easier semantics for userspace and the
kernel and make the implementation significantly simpler.
By default vfsmounts are marked with the initial user namespace and no
behavioral or performance changes are observed.
The manpage with a detailed description can be found here:
1d7b902e28
In order to support idmapped mounts, filesystems need to be changed
and mark themselves with the FS_ALLOW_IDMAP flag in fs_flags. The
patches to convert individual filesystem are not very large or
complicated overall as can be seen from the included fat, ext4, and
xfs ports. Patches for other filesystems are actively worked on and
will be sent out separately. The xfstestsuite can be used to verify
that port has been done correctly.
The mount_setattr() syscall is motivated independent of the idmapped
mounts patches and it's been around since July 2019. One of the most
valuable features of the new mount api is the ability to perform
mounts based on file descriptors only.
Together with the lookup restrictions available in the openat2()
RESOLVE_* flag namespace which we added in v5.6 this is the first time
we are close to hardened and race-free (e.g. symlinks) mounting and
path resolution.
While userspace has started porting to the new mount api to mount
proper filesystems and create new bind-mounts it is currently not
possible to change mount options of an already existing bind mount in
the new mount api since the mount_setattr() syscall is missing.
With the addition of the mount_setattr() syscall we remove this last
restriction and userspace can now fully port to the new mount api,
covering every use-case the old mount api could. We also add the
crucial ability to recursively change mount options for a whole mount
tree, both removing and adding mount options at the same time. This
syscall has been requested multiple times by various people and
projects.
There is a simple tool available at
https://github.com/brauner/mount-idmapped
that allows to create idmapped mounts so people can play with this
patch series. I'll add support for the regular mount binary should you
decide to pull this in the following weeks:
Here's an example to a simple idmapped mount of another user's home
directory:
u1001@f2-vm:/$ sudo ./mount --idmap both:1000:1001:1 /home/ubuntu/ /mnt
u1001@f2-vm:/$ ls -al /home/ubuntu/
total 28
drwxr-xr-x 2 ubuntu ubuntu 4096 Oct 28 22:07 .
drwxr-xr-x 4 root root 4096 Oct 28 04:00 ..
-rw------- 1 ubuntu ubuntu 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 ubuntu ubuntu 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 ubuntu ubuntu 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 ubuntu ubuntu 807 Feb 25 2020 .profile
-rw-r--r-- 1 ubuntu ubuntu 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 ubuntu ubuntu 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ ls -al /mnt/
total 28
drwxr-xr-x 2 u1001 u1001 4096 Oct 28 22:07 .
drwxr-xr-x 29 root root 4096 Oct 28 22:01 ..
-rw------- 1 u1001 u1001 3154 Oct 28 22:12 .bash_history
-rw-r--r-- 1 u1001 u1001 220 Feb 25 2020 .bash_logout
-rw-r--r-- 1 u1001 u1001 3771 Feb 25 2020 .bashrc
-rw-r--r-- 1 u1001 u1001 807 Feb 25 2020 .profile
-rw-r--r-- 1 u1001 u1001 0 Oct 16 16:11 .sudo_as_admin_successful
-rw------- 1 u1001 u1001 1144 Oct 28 00:43 .viminfo
u1001@f2-vm:/$ touch /mnt/my-file
u1001@f2-vm:/$ setfacl -m u:1001:rwx /mnt/my-file
u1001@f2-vm:/$ sudo setcap -n 1001 cap_net_raw+ep /mnt/my-file
u1001@f2-vm:/$ ls -al /mnt/my-file
-rw-rwxr--+ 1 u1001 u1001 0 Oct 28 22:14 /mnt/my-file
u1001@f2-vm:/$ ls -al /home/ubuntu/my-file
-rw-rwxr--+ 1 ubuntu ubuntu 0 Oct 28 22:14 /home/ubuntu/my-file
u1001@f2-vm:/$ getfacl /mnt/my-file
getfacl: Removing leading '/' from absolute path names
# file: mnt/my-file
# owner: u1001
# group: u1001
user::rw-
user:u1001:rwx
group::rw-
mask::rwx
other::r--
u1001@f2-vm:/$ getfacl /home/ubuntu/my-file
getfacl: Removing leading '/' from absolute path names
# file: home/ubuntu/my-file
# owner: ubuntu
# group: ubuntu
user::rw-
user:ubuntu:rwx
group::rw-
mask::rwx
other::r--"
* tag 'idmapped-mounts-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: (41 commits)
xfs: remove the possibly unused mp variable in xfs_file_compat_ioctl
xfs: support idmapped mounts
ext4: support idmapped mounts
fat: handle idmapped mounts
tests: add mount_setattr() selftests
fs: introduce MOUNT_ATTR_IDMAP
fs: add mount_setattr()
fs: add attr_flags_to_mnt_flags helper
fs: split out functions to hold writers
namespace: only take read lock in do_reconfigure_mnt()
mount: make {lock,unlock}_mount_hash() static
namespace: take lock_mount_hash() directly when changing flags
nfs: do not export idmapped mounts
overlayfs: do not mount on top of idmapped mounts
ecryptfs: do not mount on top of idmapped mounts
ima: handle idmapped mounts
apparmor: handle idmapped mounts
fs: make helpers idmap mount aware
exec: handle idmapped mounts
would_dump: 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/20210121131959.646623-27-christian.brauner@ubuntu.com
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
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 <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The original IMA buffer data measurement sizes were small (e.g. boot
command line), but the new buffer data measurement use cases have data
sizes that are a lot larger. Just as IMA measures the file data hash,
not the file data, IMA should similarly support the option for measuring
buffer data hash.
Introduce a boolean parameter to support measuring buffer data hash,
which would be much smaller, instead of the buffer itself.
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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 <tusharsu@linux.microsoft.com>
Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
The default IMA template used for all policy rules is the value set
for CONFIG_IMA_DEFAULT_TEMPLATE if the policy rule does not specify
a template. The default IMA template for buffer measurements should be
'ima-buf' - so that the measured buffer is correctly included in the IMA
measurement log entry.
With the default template format, buffer measurements are added to
the measurement list, but do not include the buffer data, making it
difficult, if not impossible, to validate. Including 'ima-buf'
template records in the measurement list by default, should not impact
existing attestation servers without 'ima-buf' template support.
Initialize a global 'ima-buf' template and select that template,
by default, for buffer measurements.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Rename IMA's internal filter rule functions from security_filter_rule_*()
to ima_filter_rule_*(). This avoids polluting the security_* namespace,
which is typically reserved for general security subsystem
infrastructure.
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Suggested-by: Casey Schaufler <casey@schaufler-ca.com>
[zohar@linux.ibm.com: reword using the term "filter", not "audit"]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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 <tyhicks@linux.microsoft.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: kexec@lists.infradead.org
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Use ima_validate_rule(), at the end of the token parsing stage, to
verify combinations of actions, hooks, and flags. This is useful to
increase readability by consolidating such checks into a single function
and also because rule conditionals can be specified in arbitrary order
making it difficult to do comprehensive rule validation until the entire
rule has been parsed.
This allows for the check that ties together the "keyrings" conditional
with the KEY_CHECK function hook to be moved into the final rule
validation.
The modsig check no longer needs to compiled conditionally because the
token parser will ensure that modsig support is enabled before accepting
"imasig|modsig" appraise type values. The final rule validation will
ensure that appraise_type and appraise_flag options are only present in
appraise rules.
Finally, this allows for the check that ties together the "pcr"
conditional with the measure action to be moved into the final rule
validation.
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Ask the LSM to free its audit rule rather than directly calling kfree().
Both AppArmor and SELinux do additional work in their audit_rule_free()
hooks. Fix memory leaks by allowing the LSMs to perform necessary work.
Fixes: b169424551 ("ima: use the lsm policy update notifier")
Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com>
Cc: Janne Karhunen <janne.karhunen@gmail.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Registers 8-9 are used to store measurements of the kernel and its
command line (e.g., grub2 bootloader with tpm module enabled). IMA
should include them in the boot aggregate. Registers 8-9 should be
only included in non-SHA1 digests to avoid ambiguity.
Signed-off-by: Maurizio Drocco <maurizio.drocco@ibm.com>
Reviewed-by: Bruno Meneguele <bmeneg@redhat.com>
Tested-by: Bruno Meneguele <bmeneg@redhat.com> (TPM 1.2, TPM 2.0)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
If the template field 'd' is chosen and the digest to be added to the
measurement entry was not calculated with SHA1 or MD5, it is
recalculated with SHA1, by using the passed file descriptor. However, this
cannot be done for boot_aggregate, because there is no file descriptor.
This patch adds a call to ima_calc_boot_aggregate() in
ima_eventdigest_init(), so that the digest can be recalculated also for the
boot_aggregate entry.
Cc: stable@vger.kernel.org # 3.13.x
Fixes: 3ce1217d6c ("ima: define template fields library and new helpers")
Reported-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Function hash_long() accepts unsigned long, while currently only one byte
is passed from ima_hash_key(), which calculates a key for ima_htable.
Given that hashing the digest does not give clear benefits compared to
using the digest itself, remove hash_long() and return the modulus
calculated on the first two bytes of the digest with the number of slots.
Also reduce the depth of the hash table by doubling the number of slots.
Cc: stable@vger.kernel.org
Fixes: 3323eec921 ("integrity: IMA as an integrity service provider")
Co-developed-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Krzysztof Struczynski <krzysztof.struczynski@huawei.com>
Acked-by: David.Laight@aculab.com (big endian system concerns)
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Before calculating a digest for each PCR bank, collisions were detected
with a SHA1 digest. This patch includes ima_hash_algo among the algorithms
used to calculate the template digest and checks collisions on that digest.
The position in the measurement entry array of the template digest
calculated with the IMA default hash algorithm is stored in the
ima_hash_algo_idx global variable and is determined at IMA initialization
time.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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 <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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 <roberto.sassu@huawei.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Keys queued for measurement should be freed if a custom IMA policy
was not loaded. Otherwise, the keys will remain queued forever
consuming kernel memory.
This patch defines a delayed workqueue to handle the above scenario.
The workqueue handler is setup to execute 5 minutes after IMA
initialization is completed.
If a custom IMA policy is loaded before the workqueue handler is
scheduled to execute, the workqueue task is cancelled and any queued keys
are processed for measurement. But if a custom policy was not loaded then
the queued keys are just freed when the delayed workqueue handler is run.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Reported-by: kernel test robot <rong.a.chen@intel.com> # sleeping
function called from invalid context
Reported-by: kbuild test robot <lkp@intel.com> # redefinition of
ima_init_key_queue() function.
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measuring keys requires a custom IMA policy to be loaded. Keys created
or updated before a custom IMA policy is loaded should be queued and
will be processed after a custom policy is loaded.
This patch defines a workqueue for queuing keys when a custom IMA policy
has not yet been loaded. An intermediate Kconfig boolean option namely
IMA_QUEUE_EARLY_BOOT_KEYS is used to declare the workqueue functions.
A flag namely ima_process_keys is used to check if the key should be
queued or should be processed immediately.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
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 <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Measure keys loaded onto any keyring.
This patch defines a new IMA policy func namely KEY_CHECK to
measure keys. Updated ima_match_rules() to check for KEY_CHECK
and ima_parse_rule() to handle KEY_CHECK.
Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Asymmetric private keys are used to sign multiple files. The kernel
currently supports checking against blacklisted keys. However, if the
public key is blacklisted, any file signed by the blacklisted key will
automatically fail signature verification. Blacklisting the public key
is not fine enough granularity, as we might want to only blacklist a
particular file.
This patch adds support for checking against the blacklisted hash of
the file, without the appended signature, based on the IMA policy. It
defines a new policy option "appraise_flag=check_blacklist".
In addition to the blacklisted binary hashes stored in the firmware
"dbx" variable, the Linux kernel may be configured to load blacklisted
binary hashes onto the .blacklist keyring as well. The following
example shows how to blacklist a specific kernel module hash.
$ sha256sum kernel/kheaders.ko
77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
kernel/kheaders.ko
$ grep BLACKLIST .config
CONFIG_SYSTEM_BLACKLIST_KEYRING=y
CONFIG_SYSTEM_BLACKLIST_HASH_LIST="blacklist-hash-list"
$ cat certs/blacklist-hash-list
"bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3"
Update the IMA custom measurement and appraisal policy
rules (/etc/ima-policy):
measure func=MODULE_CHECK template=ima-modsig
appraise func=MODULE_CHECK appraise_flag=check_blacklist
appraise_type=imasig|modsig
After building, installing, and rebooting the kernel:
545660333 ---lswrv 0 0 \_ blacklist:
bin:77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
measure func=MODULE_CHECK template=ima-modsig
appraise func=MODULE_CHECK appraise_flag=check_blacklist
appraise_type=imasig|modsig
modprobe: ERROR: could not insert 'kheaders': Permission denied
10 0c9834db5a0182c1fb0cdc5d3adcf11a11fd83dd ima-sig
sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40
2 /usr/lib/modules/5.4.0-rc3+/kernel/kernel/kheaders.ko
10 82aad2bcc3fa8ed94762356b5c14838f3bcfa6a0 ima-modsig
sha256:3bc6ed4f0b4d6e31bc1dbc9ef844605abc7afdc6d81a57d77a1ec9407997c40
2 /usr/lib/modules/5.4.0rc3+/kernel/kernel/kheaders.ko sha256:77fa889b3
5a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
3082029a06092a864886f70d010702a082028b30820287020101310d300b0609608648
016503040201300b06092a864886f70d01070131820264....
10 25b72217cc1152b44b134ce2cd68f12dfb71acb3 ima-buf
sha256:8b58427fedcf8f4b20bc8dc007f2e232bf7285d7b93a66476321f9c2a3aa132
b blacklisted-hash
77fa889b35a05338ec52e51591c1b89d4c8d1c99a21251d7c22b1a8642a6bad3
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
[zohar@linux.ibm.com: updated patch description]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-8-git-send-email-zohar@linux.ibm.com
process_buffer_measurement() is limited to measuring the kexec boot
command line. This patch makes process_buffer_measurement() more
generic, allowing it to measure other types of buffer data (e.g.
blacklisted binary hashes or key hashes).
process_buffer_measurement() may be called directly from an IMA hook
or as an auxiliary measurement record. In both cases the buffer
measurement is based on policy. This patch modifies the function to
conditionally retrieve the policy defined PCR and template for the IMA
hook case.
Signed-off-by: Nayna Jain <nayna@linux.ibm.com>
[zohar@linux.ibm.com: added comment in process_buffer_measurement()]
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1572492694-6520-6-git-send-email-zohar@linux.ibm.com
Pull kernel lockdown mode from James Morris:
"This is the latest iteration of the kernel lockdown patchset, from
Matthew Garrett, David Howells and others.
From the original description:
This patchset introduces an optional kernel lockdown feature,
intended to strengthen the boundary between UID 0 and the kernel.
When enabled, various pieces of kernel functionality are restricted.
Applications that rely on low-level access to either hardware or the
kernel may cease working as a result - therefore this should not be
enabled without appropriate evaluation beforehand.
The majority of mainstream distributions have been carrying variants
of this patchset for many years now, so there's value in providing a
doesn't meet every distribution requirement, but gets us much closer
to not requiring external patches.
There are two major changes since this was last proposed for mainline:
- Separating lockdown from EFI secure boot. Background discussion is
covered here: https://lwn.net/Articles/751061/
- Implementation as an LSM, with a default stackable lockdown LSM
module. This allows the lockdown feature to be policy-driven,
rather than encoding an implicit policy within the mechanism.
The new locked_down LSM hook is provided to allow LSMs to make a
policy decision around whether kernel functionality that would allow
tampering with or examining the runtime state of the kernel should be
permitted.
The included lockdown LSM provides an implementation with a simple
policy intended for general purpose use. This policy provides a coarse
level of granularity, controllable via the kernel command line:
lockdown={integrity|confidentiality}
Enable the kernel lockdown feature. If set to integrity, kernel features
that allow userland to modify the running kernel are disabled. If set to
confidentiality, kernel features that allow userland to extract
confidential information from the kernel are also disabled.
This may also be controlled via /sys/kernel/security/lockdown and
overriden by kernel configuration.
New or existing LSMs may implement finer-grained controls of the
lockdown features. Refer to the lockdown_reason documentation in
include/linux/security.h for details.
The lockdown feature has had signficant design feedback and review
across many subsystems. This code has been in linux-next for some
weeks, with a few fixes applied along the way.
Stephen Rothwell noted that commit 9d1f8be5cf ("bpf: Restrict bpf
when kernel lockdown is in confidentiality mode") is missing a
Signed-off-by from its author. Matthew responded that he is providing
this under category (c) of the DCO"
* 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits)
kexec: Fix file verification on S390
security: constify some arrays in lockdown LSM
lockdown: Print current->comm in restriction messages
efi: Restrict efivar_ssdt_load when the kernel is locked down
tracefs: Restrict tracefs when the kernel is locked down
debugfs: Restrict debugfs when the kernel is locked down
kexec: Allow kexec_file() with appropriate IMA policy when locked down
lockdown: Lock down perf when in confidentiality mode
bpf: Restrict bpf when kernel lockdown is in confidentiality mode
lockdown: Lock down tracing and perf kprobes when in confidentiality mode
lockdown: Lock down /proc/kcore
x86/mmiotrace: Lock down the testmmiotrace module
lockdown: Lock down module params that specify hardware parameters (eg. ioport)
lockdown: Lock down TIOCSSERIAL
lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down
acpi: Disable ACPI table override if the kernel is locked down
acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down
ACPI: Limit access to custom_method when the kernel is locked down
x86/msr: Restrict MSR access when the kernel is locked down
x86: Lock down IO port access when the kernel is locked down
...
Systems in lockdown mode should block the kexec of untrusted kernels.
For x86 and ARM we can ensure that a kernel is trustworthy by validating
a PE signature, but this isn't possible on other architectures. On those
platforms we can use IMA digital signatures instead. Add a function to
determine whether IMA has or will verify signatures for a given event type,
and if so permit kexec_file() even if the kernel is otherwise locked down.
This is restricted to cases where CONFIG_INTEGRITY_TRUSTED_KEYRING is set
in order to prevent an attacker from loading additional keys at runtime.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com>
Cc: linux-integrity@vger.kernel.org
Signed-off-by: James Morris <jmorris@namei.org>
If the IMA template contains the "modsig" or "d-modsig" field, then the
modsig should be added to the measurement list when the file is appraised.
And that is what normally happens, but if a measurement rule caused a file
containing a modsig to be measured before a different rule causes it to be
appraised, the resulting measurement entry will not contain the modsig
because it is only fetched during appraisal. When the appraisal rule
triggers, it won't store a new measurement containing the modsig because
the file was already measured.
We need to detect that situation and store an additional measurement with
the modsig. This is done by adding an IMA_MEASURE action flag if we read a
modsig and the IMA template contains a modsig field.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Define new "d-modsig" template field which holds the digest that is
expected to match the one contained in the modsig, and also new "modsig"
template field which holds the appended file signature.
Add a new "ima-modsig" defined template descriptor with the new fields as
well as the ones from the "ima-sig" descriptor.
Change ima_store_measurement() to accept a struct modsig * argument so that
it can be passed along to the templates via struct ima_event_data.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Obtain the modsig and calculate its corresponding hash in
ima_collect_measurement().
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Implement the appraise_type=imasig|modsig option, allowing IMA to read and
verify modsig signatures.
In case a file has both an xattr signature and an appended modsig, IMA will
only use the appended signature if the key used by the xattr signature
isn't present in the IMA or platform keyring.
Because modsig verification needs to convert from an integrity keyring id
to the keyring itself, add an integrity_keyring_from_id() function in
digsig.c so that integrity_modsig_verify() can use it.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Introduce the modsig keyword to the IMA policy syntax to specify that
a given hook should expect the file to have the IMA signature appended
to it. Here is how it can be used in a rule:
appraise func=KEXEC_KERNEL_CHECK appraise_type=imasig|modsig
With this rule, IMA will accept either a signature stored in the extended
attribute or an appended signature.
For now, the rule above will behave exactly the same as if
appraise_type=imasig was specified. The actual modsig implementation
will be introduced separately.
Suggested-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull integrity updates from Mimi Zohar:
"Bug fixes, code clean up, and new features:
- IMA policy rules can be defined in terms of LSM labels, making the
IMA policy dependent on LSM policy label changes, in particular LSM
label deletions. The new environment, in which IMA-appraisal is
being used, frequently updates the LSM policy and permits LSM label
deletions.
- Prevent an mmap'ed shared file opened for write from also being
mmap'ed execute. In the long term, making this and other similar
changes at the VFS layer would be preferable.
- The IMA per policy rule template format support is needed for a
couple of new/proposed features (eg. kexec boot command line
measurement, appended signatures, and VFS provided file hashes).
- Other than the "boot-aggregate" record in the IMA measuremeent
list, all other measurements are of file data. Measuring and
storing the kexec boot command line in the IMA measurement list is
the first buffer based measurement included in the measurement
list"
* 'next-integrity' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity:
integrity: Introduce struct evm_xattr
ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition
KEXEC: Call ima_kexec_cmdline to measure the boot command line args
IMA: Define a new template field buf
IMA: Define a new hook to measure the kexec boot command line arguments
IMA: support for per policy rule template formats
integrity: Fix __integrity_init_keyring() section mismatch
ima: Use designated initializers for struct ima_event_data
ima: use the lsm policy update notifier
LSM: switch to blocking policy update notifiers
x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY
ima: Make arch_policy_entry static
ima: prevent a file already mmap'ed write to be mmap'ed execute
x86/ima: check EFI SetupMode too
A buffer(kexec boot command line arguments) measured into IMA
measuremnt list cannot be appraised, without already being
aware of the buffer contents. Since hashes are non-reversible,
raw buffer is needed for validation or regenerating hash for
appraisal/attestation.
Add support to store/read the buffer contents in HEX.
The kexec cmdline hash is stored in the "d-ng" field of the
template data. It can be verified using
sudo cat /sys/kernel/security/integrity/ima/ascii_runtime_measurements |
grep kexec-cmdline | cut -d' ' -f 6 | xxd -r -p | sha256sum
- Add two new fields to ima_event_data to hold the buf and
buf_len
- Add a new template field 'buf' to be used to store/read
the buffer data.
- Updated process_buffer_meaurement to add the buffer to
ima_event_data. process_buffer_measurement added in
"Define a new IMA hook to measure the boot command line
arguments"
- Add a new template policy name ima-buf to represent
'd-ng|n-ng|buf'
Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Reviewed-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: James Morris <jamorris@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Currently during soft reboot(kexec_file_load) boot command line
arguments are not measured. Define hooks needed to measure kexec
command line arguments during soft reboot(kexec_file_load).
- A new ima hook ima_kexec_cmdline is defined to be called by the
kexec code.
- A new function process_buffer_measurement is defined to measure
the buffer hash into the IMA measurement list.
- A new func policy KEXEC_CMDLINE is defined to control the
measurement.
Signed-off-by: Prakhar Srivastava <prsriva02@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Admins may wish to log different measurements using different IMA
templates. Add support for overriding the default template on a per-rule
basis.
Inspired-by: Roberto Sassu <roberto.sassu@huawei.com>
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Don't do lazy policy updates while running the rule matching,
run the updates as they happen.
Depends on commit f242064c5df3 ("LSM: switch to blocking policy update notifiers")
Signed-off-by: Janne Karhunen <janne.karhunen@gmail.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license as published by
the free software foundation version 2 of the license
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 315 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Armijn Hemel <armijn@tjaldur.nl>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190531190115.503150771@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Pull tpm updates from James Morris:
- Clean up the transmission flow
Cleaned up the whole transmission flow. Locking of the chip is now
done in the level of tpm_try_get_ops() and tpm_put_ops() instead
taking the chip lock inside tpm_transmit(). The nested calls inside
tpm_transmit(), used with the resource manager, have been refactored
out.
Should make easier to perform more complex transactions with the TPM
without making the subsystem a bigger mess (e.g. encrypted channel
patches by James Bottomley).
- PPI 1.3 support
TPM PPI 1.3 introduces an additional optional command parameter that
may be needed for some commands. Display the parameter if the command
requires such a parameter. Only command 23 (SetPCRBanks) needs one.
The PPI request file will show output like this then:
# echo "23 16" > request
# cat request
23 16
# echo "5" > request
# cat request
5
- Extend all PCR banks in IMA
Instead of static PCR banks array, the array of available PCR banks
is now allocated dynamically. The digests sizes are determined
dynamically using a probe PCR read without relying crypto's static
list of hash algorithms.
This should finally make sealing of measurements in IMA safe and
secure.
- TPM 2.0 selftests
Added a test suite to tools/testing/selftests/tpm2 previously outside
of the kernel tree: https://github.com/jsakkine-intel/tpm2-scripts
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (37 commits)
tpm/ppi: Enable submission of optional command parameter for PPI 1.3
tpm/ppi: Possibly show command parameter if TPM PPI 1.3 is used
tpm/ppi: Display up to 101 operations as define for version 1.3
tpm/ppi: rename TPM_PPI_REVISION_ID to TPM_PPI_REVISION_ID_1
tpm/ppi: pass function revision ID to tpm_eval_dsm()
tpm: pass an array of tpm_extend_digest structures to tpm_pcr_extend()
KEYS: trusted: explicitly use tpm_chip structure from tpm_default_chip()
tpm: move tpm_chip definition to include/linux/tpm.h
tpm: retrieve digest size of unknown algorithms with PCR read
tpm: rename and export tpm2_digest and tpm2_algorithms
tpm: dynamically allocate the allocated_banks array
tpm: remove @flags from tpm_transmit()
tpm: take TPM chip power gating out of tpm_transmit()
tpm: introduce tpm_chip_start() and tpm_chip_stop()
tpm: remove TPM_TRANSMIT_UNLOCKED flag
tpm: use tpm_try_get_ops() in tpm-sysfs.c.
tpm: remove @space from tpm_transmit()
tpm: move TPM space code out of tpm_transmit()
tpm: move tpm_validate_commmand() to tpm2-space.c
tpm: clean up tpm_try_transmit() error handling flow
...
Currently, tpm_pcr_extend() accepts as an input only a SHA1 digest.
This patch replaces the hash parameter of tpm_pcr_extend() with an array of
tpm_digest structures, so that the caller can provide a digest for each PCR
bank currently allocated in the TPM.
tpm_pcr_extend() will not extend banks for which no digest was provided,
as it happened before this patch, but instead it requires that callers
provide the full set of digests. Since the number of digests will always be
chip->nr_allocated_banks, the count parameter has been removed.
Due to the API change, ima_pcr_extend() and pcrlock() have been modified.
Since the number of allocated banks is not known in advance, the memory for
the digests must be dynamically allocated. To avoid performance degradation
and to avoid that a PCR extend is not done due to lack of memory, the array
of tpm_digest structures is allocated by the users of the TPM driver at
initialization time.
Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Tested-by: Mimi Zohar <zohar@linux.ibm.com> (on x86 for TPM 1.2 & PTT TPM 2.0)
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
The audit_rule_match() struct audit_context *actx parameter is not used
by any in-tree consumers (selinux, apparmour, integrity, smack).
The audit context is an internal audit structure that should only be
accessed by audit accessor functions.
It was part of commit 03d37d25e0 ("LSM/Audit: Introduce generic
Audit LSM hooks") but appears to have never been used.
Remove it.
Please see the github issue
https://github.com/linux-audit/audit-kernel/issues/107
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
[PM: fixed the referenced commit title]
Signed-off-by: Paul Moore <paul@paul-moore.com>
Constify some static data that is never modified,
so that it is placed in .rodata.
Signed-off-by: Eric Biggers <ebiggers@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
Pull TPM updates from James Morris:
- Migrate away from PM runtime as explicit cmdReady/goIdle transactions
for every command is a spec requirement. PM runtime adds only a layer
of complexity on our case.
- tpm_tis drivers can now specify the hwrng quality.
- TPM 2.0 code uses now tpm_buf for constructing messages. Jarkko
thinks Tomas Winkler has done the same for TPM 1.2, and will start
digging those changes from the patchwork in the near future.
- Bug fixes and clean ups
* 'next-tpm' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
ima: Get rid of ima_used_chip and use ima_tpm_chip != NULL instead
ima: Use tpm_default_chip() and call TPM functions with a tpm_chip
tpm: replace TPM_TRANSMIT_RAW with TPM_TRANSMIT_NESTED
tpm: Convert tpm_find_get_ops() to use tpm_default_chip()
tpm: Implement tpm_default_chip() to find a TPM chip
tpm: rename tpm_chip_find_get() to tpm_find_get_ops()
tpm: Allow tpm_tis drivers to set hwrng quality.
tpm: Return the actual size when receiving an unsupported command
tpm: separate cmd_ready/go_idle from runtime_pm
tpm/tpm_i2c_infineon: switch to i2c_lock_bus(..., I2C_LOCK_SEGMENT)
tpm_tis_spi: Pass the SPI IRQ down to the driver
tpm: migrate tpm2_get_random() to use struct tpm_buf
tpm: migrate tpm2_get_tpm_pt() to use struct tpm_buf
tpm: migrate tpm2_probe() to use struct tpm_buf
tpm: migrate tpm2_shutdown() to use struct tpm_buf
Pull security subsystem updates from James Morris:
- kstrdup() return value fix from Eric Biggers
- Add new security_load_data hook to differentiate security checking of
kernel-loaded binaries in the case of there being no associated file
descriptor, from Mimi Zohar.
- Add ability to IMA to specify a policy at build-time, rather than
just via command line params or by loading a custom policy, from
Mimi.
- Allow IMA and LSMs to prevent sysfs firmware load fallback (e.g. if
using signed firmware), from Mimi.
- Allow IMA to deny loading of kexec kernel images, as they cannot be
measured by IMA, from Mimi.
* 'next-general' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
security: check for kstrdup() failure in lsm_append()
security: export security_kernel_load_data function
ima: based on policy warn about loading firmware (pre-allocated buffer)
module: replace the existing LSM hook in init_module
ima: add build time policy
ima: based on policy require signed firmware (sysfs fallback)
firmware: add call to LSM hook before firmware sysfs fallback
ima: based on policy require signed kexec kernel images
kexec: add call to LSM hook in original kexec_load syscall
security: define new LSM hook named security_kernel_load_data
MAINTAINERS: remove the outdated "LINUX SECURITY MODULE (LSM) FRAMEWORK" entry
Get rid of ima_used_chip and use ima_tpm_chip variable instead for
determining whether to use the TPM chip.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Rather than accessing the TPM functions by passing a NULL pointer for
the tpm_chip, which causes a lookup for a suitable chip every time, get a
hold of a tpm_chip and access the TPM functions using it.
Signed-off-by: Stefan Berger <stefanb@linux.vnet.ibm.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
The original kexec_load syscall can not verify file signatures, nor can
the kexec image be measured. Based on policy, deny the kexec_load
syscall.
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: Eric Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: James Morris <james.morris@microsoft.com>
just check ->f_mode in ima_appraise_measurement()
Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Commit a756024 ("ima: added ima_policy_flag variable") replaced
ima_initialized with ima_policy_flag, but didn't remove ima_initialized.
This patch removes it.
Signed-off-by: Petr Vorel <pvorel@suse.cz>
Reviewed-by: James Morris <james.morris@microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
The existing BPRM_CHECK functionality in IMA validates against the
credentials of the existing process, not any new credentials that the
child process may transition to. Add an additional CREDS_CHECK target
and refactor IMA to pass the appropriate creds structure. In
ima_bprm_check(), check with both the existing process credentials and
the credentials that will be committed when the new process is started.
This will not change behaviour unless the system policy is extended to
include CREDS_CHECK targets - BPRM_CHECK will continue to check the same
credentials that it did previously.
After this patch, an IMA policy rule along the lines of:
measure func=CREDS_CHECK subj_type=unconfined_t
will trigger if a process is executed and runs as unconfined_t, ignoring
the context of the parent process. This is in contrast to:
measure func=BPRM_CHECK subj_type=unconfined_t
which will trigger if the process that calls exec() is already executing
in unconfined_t, ignoring the context that the child process executes
into.
Signed-off-by: Matthew Garrett <mjg59@google.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Changelog:
- initialize ima_creds_status
Lakshmi Ramasubramanian