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* x86/kexec: Carry forward IMA measurement log on kexecJonathan McDowell2022-07-011-0/+5
| | | | | | | | | | | | | | | | | | | | | | On kexec file load, the Integrity Measurement Architecture (IMA) subsystem may verify the IMA signature of the kernel and initramfs, and measure it. The command line parameters passed to the kernel in the kexec call may also be measured by IMA. A remote attestation service can verify a TPM quote based on the TPM event log, the IMA measurement list and the TPM PCR data. This can be achieved only if the IMA measurement log is carried over from the current kernel to the next kernel across the kexec call. PowerPC and ARM64 both achieve this using device tree with a "linux,ima-kexec-buffer" node. x86 platforms generally don't make use of device tree, so use the setup_data mechanism to pass the IMA buffer to the new kernel. Signed-off-by: Jonathan McDowell <noodles@fb.com> Signed-off-by: Borislav Petkov <bp@suse.de> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> # IMA function definitions Link: https://lore.kernel.org/r/YmKyvlF3my1yWTvK@noodles-fedora-PC23Y6EG
* ima: Fix undefined arch_ima_get_secureboot() and coTakashi Iwai2021-12-241-15/+15
| | | | | | | | | | | | | | Currently arch_ima_get_secureboot() and arch_get_ima_policy() are defined only when CONFIG_IMA is set, and this makes any code calling those functions without CONFIG_IMA fail. Move the declaration and the dummy definition of those functions outside ifdef-CONFIG_IMA block for fixing the undefined symbols. Signed-off-by: Takashi Iwai <tiwai@suse.de> [zohar@linux.ibm.com: removed in-tree/out-of-tree comment in patch description] Reviewed-by: Petr Vorel <pvorel@suse.cz> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* ima: Add digest and digest_len params to the functions to measure a bufferRoberto Sassu2021-07-231-2/+3
| | | | | | | | | | | | | | | This patch performs the final modification necessary to pass the buffer measurement to callers, so that they provide a functionality similar to ima_file_hash(). It adds the 'digest' and 'digest_len' parameters to ima_measure_critical_data() and process_buffer_measurement(). These functions calculate the digest even if there is no suitable rule in the IMA policy and, in this case, they simply return 1 before generating a new measurement entry. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* ima: Return int in the functions to measure a bufferRoberto Sassu2021-07-231-6/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | ima_measure_critical_data() and process_buffer_measurement() currently don't return a result as, unlike appraisal-related functions, the result is not used by callers to deny an operation. Measurement-related functions instead rely on the audit subsystem to notify the system administrator when an error occurs. However, ima_measure_critical_data() and process_buffer_measurement() are a special case, as these are the only functions that can return a buffer measurement (for files, there is ima_file_hash()). In a subsequent patch, they will be modified to return the calculated digest. In preparation to return the result of the digest calculation, this patch modifies the return type from void to int, and returns 0 if the buffer has been successfully measured, a negative value otherwise. Given that the result of the measurement is still not necessary, this patch does not modify the behavior of existing callers by processing the returned value. For those, the return value is ignored. Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Acked-by: Paul Moore <paul@paul-moore.com> (for the SELinux bits) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* ima: Introduce ima_get_current_hash_algo()Roberto Sassu2021-07-231-0/+7
| | | | | | | | | | | | | | | | | | | | | | | Buffer measurements, unlike file measurements, are not accessible after the measurement is done, as buffers are not suitable for use with the integrity_iint_cache structure (there is no index, for files it is the inode number). In the subsequent patches, the measurement (digest) will be returned directly by the functions that perform the buffer measurement, ima_measure_critical_data() and process_buffer_measurement(). A caller of those functions also needs to know the algorithm used to calculate the digest. Instead of adding the algorithm as a new parameter to the functions, this patch provides it separately with the new function ima_get_current_hash_algo(). Since the hash algorithm does not change after the IMA setup phase, there is no risk of races (obtaining a digest calculated with a different algorithm than the one returned). Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> [zohar@linux.ibm.com: annotate ima_hash_algo as __ro_after_init] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds2021-02-231-6/+12
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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.pdf https://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: https://git.kernel.org/brauner/man-pages/c/1d7b902e2875a1ff342e036a9f866a995640aea8 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: handle idmapped mountsChristian Brauner2021-01-241-6/+12
| | | | | | | | | | | | | | | | | | | | | | 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: extend critical data hook to limit the measurement based on a labelTushar Sugandhi2021-01-141-2/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The IMA hook ima_measure_critical_data() does not support a way to specify the source of the critical data provider. Thus, the data measurement cannot be constrained based on the data source label in the IMA policy. Extend the IMA hook ima_measure_critical_data() to support passing the data source label as an input parameter, so that the policy rule can be used to limit the measurements based on the label. 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: define a hook to measure kernel integrity critical dataTushar Sugandhi2021-01-141-0/+7
|/ | | | | | | | | | | | | | | | 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>
* Merge tag 'integrity-v5.11' of ↵Linus Torvalds2020-12-161-0/+6
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity subsystem updates from Mimi Zohar: "Just three patches here. Other integrity changes are being upstreamed via EFI (defines a common EFI secure and trusted boot IMA policy) and BPF LSM (exporting the IMA file cache hash info based on inode). The three patches included here: - bug fix: fail calculating the file hash, when a file not opened for read and the attempt to re-open it for read fails. - defer processing the "ima_appraise" boot command line option to avoid enabling different modes (e.g. fix, log) to when the secure boot flag is available on arm. - defines "ima-buf" as the default IMA buffer measurement template in preparation for the builtin integrity "critical data" policy" * tag 'integrity-v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: ima: Don't modify file descriptor mode on the fly ima: select ima-buf template for buffer measurement ima: defer arch_ima_get_secureboot() call to IMA init time
| * ima: defer arch_ima_get_secureboot() call to IMA init timeArd Biesheuvel2020-11-021-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Chester reports that it is necessary to introduce a new way to pass the EFI secure boot status between the EFI stub and the core kernel on ARM systems. The usual way of obtaining this information is by checking the SecureBoot and SetupMode EFI variables, but this can only be done after the EFI variable workqueue is created, which occurs in a subsys_initcall(), whereas arch_ima_get_secureboot() is called much earlier by the IMA framework. However, the IMA framework itself is started as a late_initcall, and the only reason the call to arch_ima_get_secureboot() occurs so early is because it happens in the context of a __setup() callback that parses the ima_appraise= command line parameter. So let's refactor this code a little bit, by using a core_param() callback to capture the command line argument, and deferring any reasoning based on its contents to the IMA init routine. Cc: Chester Lin <clin@suse.com> Cc: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Link: https://lore.kernel.org/linux-arm-kernel/20200904072905.25332-2-clin@suse.com/ Signed-off-by: Ard Biesheuvel <ardb@kernel.org> Reported-by: kernel test robot <lkp@intel.com> [missing core_param()] [zohar@linux.ibm.com: included linux/module.h] Tested-by: Chester Lin <clin@suse.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* | ima: Implement ima_inode_hashKP Singh2020-11-261-0/+6
|/ | | | | | | | | | | | | | | | | | | | | This is in preparation to add a helper for BPF LSM programs to use IMA hashes when attached to LSM hooks. There are LSM hooks like inode_unlink which do not have a struct file * argument and cannot use the existing ima_file_hash API. An inode based API is, therefore, useful in LSM based detections like an executable trying to delete itself which rely on the inode_unlink LSM hook. Moreover, the ima_file_hash function does nothing with the struct file pointer apart from calling file_inode on it and converting it to an inode. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Yonghong Song <yhs@fb.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/bpf/20201124151210.1081188-2-kpsingh@chromium.org
* LSM: Add "contents" flag to kernel_read_file hookKees Cook2020-10-051-2/+4
| | | | | | | | | | | | | | | | | | | As with the kernel_load_data LSM hook, add a "contents" flag to the kernel_read_file LSM hook that indicates whether the LSM can expect a matching call to the kernel_post_read_file LSM hook with the full contents of the file. With the coming addition of partial file read support for kernel_read_file*() API, the LSM will no longer be able to always see the entire contents of a file during the read calls. For cases where the LSM must read examine the complete file contents, it will need to do so on its own every time the kernel_read_file hook is called with contents=false (or reject such cases). Adjust all existing LSMs to retain existing behavior. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/r/20201002173828.2099543-12-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* LSM: Introduce kernel_post_load_data() hookKees Cook2020-10-051-2/+11
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are a few places in the kernel where LSMs would like to have visibility into the contents of a kernel buffer that has been loaded or read. While security_kernel_post_read_file() (which includes the buffer) exists as a pairing for security_kernel_read_file(), no such hook exists to pair with security_kernel_load_data(). Earlier proposals for just using security_kernel_post_read_file() with a NULL file argument were rejected (i.e. "file" should always be valid for the security_..._file hooks, but it appears at least one case was left in the kernel during earlier refactoring. (This will be fixed in a subsequent patch.) Since not all cases of security_kernel_load_data() can have a single contiguous buffer made available to the LSM hook (e.g. kexec image segments are separately loaded), there needs to be a way for the LSM to reason about its expectations of the hook coverage. In order to handle this, add a "contents" argument to the "kernel_load_data" hook that indicates if the newly added "kernel_post_load_data" hook will be called with the full contents once loaded. That way, LSMs requiring full contents can choose to unilaterally reject "kernel_load_data" with contents=false (which is effectively the existing hook coverage), but when contents=true they can allow it and later evaluate the "kernel_post_load_data" hook once the buffer is loaded. With this change, LSMs can gain coverage over non-file-backed data loads (e.g. init_module(2) and firmware userspace helper), which will happen in subsequent patches. Additionally prepare IMA to start processing these cases. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: KP Singh <kpsingh@google.com> Link: https://lore.kernel.org/r/20201002173828.2099543-9-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* fs/kernel_read_file: Split into separate include fileScott Branden2020-10-051-0/+1
| | | | | | | | | | | | | | | | | | Move kernel_read_file* out of linux/fs.h to its own linux/kernel_read_file.h include file. That header gets pulled in just about everywhere and doesn't really need functions not related to the general fs interface. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Scott Branden <scott.branden@broadcom.com> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Acked-by: James Morris <jamorris@linux.microsoft.com> Link: https://lore.kernel.org/r/20200706232309.12010-2-scott.branden@broadcom.com Link: https://lore.kernel.org/r/20201002173828.2099543-4-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ima: Support additional conditionals in the KEXEC_CMDLINE hook functionTyler Hicks2020-07-201-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* ima: verify mprotect change is consistent with mmap policyMimi Zohar2020-05-221-0/+7
| | | | | | | | | | | | | Files can be mmap'ed read/write and later changed to execute to circumvent IMA's mmap appraise policy rules. Due to locking issues (mmap semaphore would be taken prior to i_mutex), files can not be measured or appraised at this point. Eliminate this integrity gap, by denying the mprotect PROT_EXECUTE change, if an mmap appraise policy rule exists. On mprotect change success, return 0. On failure, return -EACESS. Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* ima: add a new CONFIG for loading arch-specific policiesNayna Jain2020-03-121-2/+1
| | | | | | | | | | | | | | | Every time a new architecture defines the IMA architecture specific functions - arch_ima_get_secureboot() and arch_ima_get_policy(), the IMA include file needs to be updated. To avoid this "noise", this patch defines a new IMA Kconfig IMA_SECURE_AND_OR_TRUSTED_BOOT option, allowing the different architectures to select it. Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Acked-by: Ard Biesheuvel <ardb@kernel.org> Acked-by: Philipp Rudo <prudo@linux.ibm.com> (s390) Acked-by: Michael Ellerman <mpe@ellerman.id.au> (powerpc) Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* ima: add the ability to query the cached hash of a given fileFlorent Revest2020-01-221-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | This allows other parts of the kernel (perhaps a stacked LSM allowing system monitoring, eg. the proposed KRSI LSM [1]) to retrieve the hash of a given file from IMA if it's present in the iint cache. It's true that the existence of the hash means that it's also in the audit logs or in /sys/kernel/security/ima/ascii_runtime_measurements, but it can be difficult to pull that information out for every subsequent exec. This is especially true if a given host has been up for a long time and the file was first measured a long time ago. It should be kept in mind that this function gives access to cached entries which can be removed, for instance on security_inode_free(). This is based on Peter Moody's patch: https://sourceforge.net/p/linux-ima/mailman/message/33036180/ [1] https://lkml.org/lkml/2019/9/10/393 Signed-off-by: Florent Revest <revest@google.com> Reviewed-by: KP Singh <kpsingh@chromium.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* IMA: fix measuring asymmetric keys KconfigLakshmi Ramasubramanian2020-01-091-2/+2
| | | | | | | | | | | | | | | | | | | As a result of the asymmetric public keys subtype Kconfig option being defined as tristate, with the existing IMA Makefile, ima_asymmetric_keys.c could be built as a kernel module. To prevent this from happening, this patch defines and uses an intermediate Kconfig boolean option named IMA_MEASURE_ASYMMETRIC_KEYS. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: James.Bottomley <James.Bottomley@HansenPartnership.com> Cc: David Howells <dhowells@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reported-by: kbuild test robot <lkp@intel.com> # ima_asymmetric_keys.c is built as a kernel module. Fixes: 88e70da170e8 ("IMA: Define an IMA hook to measure keys") Fixes: cb1aa3823c92 ("KEYS: Call the IMA hook to measure keys") [zohar@linux.ibm.com: updated patch description] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* KEYS: Call the IMA hook to measure keysLakshmi Ramasubramanian2019-12-121-0/+14
| | | | | | | | | | | | | Call the IMA hook from key_create_or_update() function to measure the payload when a new key is created or an existing key is updated. This patch adds the call to the IMA hook from key_create_or_update() function to measure the key on key create or update. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Cc: David Howells <dhowells@redhat.com> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* powerpc/ima: Add support to initialize ima policy rulesNayna Jain2019-11-121-1/+2
| | | | | | | | | | | | | | | | | | PowerNV systems use a Linux-based bootloader, which rely on the IMA subsystem to enforce different secure boot modes. Since the verification policy may differ based on the secure boot mode of the system, the policies must be defined at runtime. This patch implements arch-specific support to define IMA policy rules based on the runtime secure boot mode of the system. This patch provides arch-specific IMA policies if PPC_SECURE_BOOT config is enabled. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au> Link: https://lore.kernel.org/r/1572492694-6520-3-git-send-email-zohar@linux.ibm.com
* Merge branch 'next-lockdown' of ↵Linus Torvalds2019-09-281-0/+9
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 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 9d1f8be5cf42 ("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 ...
| * kexec: Allow kexec_file() with appropriate IMA policy when locked downMatthew Garrett2019-08-191-0/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | Merge branch 'next-integrity' of ↵Linus Torvalds2019-07-081-0/+2
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity 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
| * IMA: Define a new hook to measure the kexec boot command line argumentsPrakhar Srivastava2019-06-241-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 441Thomas Gleixner2019-06-051-4/+1
|/ | | | | | | | | | | | | | | | | | | | | 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>
* s390/kexec_file: Disable kexec_load when IPLed securePhilipp Rudo2019-04-291-1/+1
| | | | | | | | | A kernel loaded via kexec_load cannot be verified. Thus disable kexec_load systemcall in kernels which where IPLed securely. Use the IMA mechanism to do so. Signed-off-by: Philipp Rudo <prudo@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* ima: define ima_post_create_tmpfile() hook and add missing callMimi Zohar2019-02-041-0/+5
| | | | | | | | | | | | | | | If tmpfiles can be made persistent, then newly created tmpfiles need to be treated like any other new files in policy. This patch indicates which newly created tmpfiles are in policy, causing the file hash to be calculated on __fput(). Reported-by: Ignaz Forster <ignaz.forster@gmx.de> [rgoldwyn@suse.com: Call ima_post_create_tmpfile() in vfs_tmpfile() as opposed to do_tmpfile(). This will help the case for overlayfs where copy_up is denied while overwriting a file.] Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* x86/ima: retry detecting secure boot modeMimi Zohar2018-12-111-1/+1
| | | | | | | | The secure boot mode may not be detected on boot for some reason (eg. buggy firmware). This patch attempts one more time to detect the secure boot mode. Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* x86/ima: define arch_get_ima_policy() for x86Eric Richter2018-12-111-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | On x86, there are two methods of verifying a kexec'ed kernel image signature being loaded via the kexec_file_load syscall - an architecture specific implementaton or a IMA KEXEC_KERNEL_CHECK appraisal rule. Neither of these methods verify the kexec'ed kernel image signature being loaded via the kexec_load syscall. Secure boot enabled systems require kexec images to be signed. Therefore, this patch loads an IMA KEXEC_KERNEL_CHECK policy rule on secure boot enabled systems not configured with CONFIG_KEXEC_VERIFY_SIG enabled. When IMA_APPRAISE_BOOTPARAM is configured, different IMA appraise modes (eg. fix, log) can be specified on the boot command line, allowing unsigned or invalidly signed kernel images to be kexec'ed. This patch permits enabling IMA_APPRAISE_BOOTPARAM or IMA_ARCH_POLICY, but not both. Signed-off-by: Eric Richter <erichte@linux.ibm.com> Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Cc: David Howells <dhowells@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Peter Jones <pjones@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Young <dyoung@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* ima: add support for arch specific policiesNayna Jain2018-12-111-0/+5
| | | | | | | | | | | | | | | | | | Builtin IMA policies can be enabled on the boot command line, and replaced with a custom policy, normally during early boot in the initramfs. Build time IMA policy rules were recently added. These rules are automatically enabled on boot and persist after loading a custom policy. There is a need for yet another type of policy, an architecture specific policy, which is derived at runtime during kernel boot, based on the runtime secure boot flags. Like the build time policy rules, these rules persist after loading a custom policy. This patch adds support for loading an architecture specific IMA policy. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Co-Developed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* x86/ima: define arch_ima_get_securebootNayna Jain2018-11-131-0/+9
| | | | | | | | | | | | | | | | | | | Distros are concerned about totally disabling the kexec_load syscall. As a compromise, the kexec_load syscall will only be disabled when CONFIG_KEXEC_VERIFY_SIG is configured and the system is booted with secureboot enabled. This patch defines the new arch specific function called arch_ima_get_secureboot() to retrieve the secureboot state of the system. Signed-off-by: Nayna Jain <nayna@linux.ibm.com> Suggested-by: Seth Forshee <seth.forshee@canonical.com> Cc: David Howells <dhowells@redhat.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: Peter Jones <pjones@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Dave Young <dyoung@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* Merge branch 'next-general' of ↵Linus Torvalds2018-08-151-0/+7
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 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
| * ima: based on policy require signed kexec kernel imagesMimi Zohar2018-07-161-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | IMA: don't propagate opened through the entire thingAl Viro2018-07-121-2/+2
|/ | | | | | | 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>
* ima: define is_ima_appraise_enabled()Mimi Zohar2017-06-211-0/+6
| | | | | | | | | Only return enabled if in enforcing mode, not fix or log modes. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Changes: - Define is_ima_appraise_enabled() as a bool (Thiago Bauermann)
* ima: on soft reboot, save the measurement listMimi Zohar2016-12-201-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | The TPM PCRs are only reset on a hard reboot. In order to validate a TPM's quote after a soft reboot (eg. kexec -e), the IMA measurement list of the running kernel must be saved and restored on boot. This patch uses the kexec buffer passing mechanism to pass the serialized IMA binary_runtime_measurements to the next kernel. Link: http://lkml.kernel.org/r/1480554346-29071-7-git-send-email-zohar@linux.vnet.ibm.com Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@gmail.com> Cc: Andreas Steffen <andreas.steffen@strongswan.org> Cc: Josh Sklar <sklar@linux.vnet.ibm.com> Cc: Dave Young <dyoung@redhat.com> Cc: Vivek Goyal <vgoyal@redhat.com> Cc: Baoquan He <bhe@redhat.com> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Stewart Smith <stewart@linux.vnet.ibm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* ima: add support for creating files using the mknodat syscallMimi Zohar2016-05-011-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | Commit 3034a14 "ima: pass 'opened' flag to identify newly created files" stopped identifying empty files as new files. However new empty files can be created using the mknodat syscall. On systems with IMA-appraisal enabled, these empty files are not labeled with security.ima extended attributes properly, preventing them from subsequently being opened in order to write the file data contents. This patch defines a new hook named ima_post_path_mknod() to mark these empty files, created using mknodat, as new in order to allow the file data contents to be written. In addition, files with security.ima xattrs containing a file signature are considered "immutable" and can not be modified. The file contents need to be written, before signing the file. This patch relaxes this requirement for new files, allowing the file signature to be written before the file contents. Changelog: - defer identifying files with signatures stored as security.ima (based on Dmitry Rozhkov's comments) - removing tests (eg. dentry, dentry->d_inode, inode->i_size == 0) (based on Al's review) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: Al Viro <<viro@zeniv.linux.org.uk> Tested-by: Dmitry Rozhkov <dmitry.rozhkov@linux.intel.com>
* module: replace copy_module_from_fd with kernel versionMimi Zohar2016-02-211-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | Replace copy_module_from_fd() with kernel_read_file_from_fd(). Although none of the upstreamed LSMs define a kernel_module_from_file hook, IMA is called, based on policy, to prevent unsigned kernel modules from being loaded by the original kernel module syscall and to measure/appraise signed kernel modules. The security function security_kernel_module_from_file() was called prior to reading a kernel module. Preventing unsigned kernel modules from being loaded by the original kernel module syscall remains on the pre-read kernel_read_file() security hook. Instead of reading the kernel module twice, once for measuring/appraising and again for loading the kernel module, the signature validation is moved to the kernel_post_read_file() security hook. This patch removes the security_kernel_module_from_file() hook and security call. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Cc: Rusty Russell <rusty@rustcorp.com.au>
* security: define kernel_read_file hookMimi Zohar2016-02-211-0/+6
| | | | | | | | | | | | | The kernel_read_file security hook is called prior to reading the file into memory. Changelog v4+: - export security_kernel_read_file() Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
* firmware: replace call to fw_read_file_contents() with kernel versionMimi Zohar2016-02-211-6/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | Replace the fw_read_file_contents with kernel_file_read_from_path(). Although none of the upstreamed LSMs define a kernel_fw_from_file hook, IMA is called by the security function to prevent unsigned firmware from being loaded and to measure/appraise signed firmware, based on policy. Instead of reading the firmware twice, once for measuring/appraising the firmware and again for reading the firmware contents into memory, the kernel_post_read_file() security hook calculates the file hash based on the in memory file buffer. The firmware is read once. This patch removes the LSM kernel_fw_from_file() hook and security call. Changelog v4+: - revert dropped buf->size assignment - reported by Sergey Senozhatsky v3: - remove kernel_fw_from_file hook - use kernel_file_read_from_path() - requested by Luis v2: - reordered and squashed firmware patches - fix MAX firmware size (Kees Cook) Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Luis R. Rodriguez <mcgrof@kernel.org>
* ima: define a new hook to measure and appraise a file already in memoryMimi Zohar2016-02-201-0/+8
| | | | | | | | | | | | | | | | | | This patch defines a new IMA hook ima_post_read_file() for measuring and appraising files read by the kernel. The caller loads the file into memory before calling this function, which calculates the hash followed by the normal IMA policy based processing. Changelog v5: - fail ima_post_read_file() if either file or buf is NULL v3: - rename ima_hash_and_process_file() to ima_post_read_file() v1: - split patch Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@huawei.com>
* ima: pass 'opened' flag to identify newly created filesDmitry Kasatkin2014-09-091-2/+2
| | | | | | | | | | Empty files and missing xattrs do not guarantee that a file was just created. This patch passes FILE_CREATED flag to IMA to reliably identify new files. Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com> Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: <stable@vger.kernel.org> 3.14+
* ima: add support for measuring and appraising firmwareMimi Zohar2014-07-251-0/+6
| | | | | | | | | | | | | The "security: introduce kernel_fw_from_file hook" patch defined a new security hook to evaluate any loaded firmware that wasn't built into the kernel. This patch defines ima_fw_from_file(), which is called from the new security hook, to measure and/or appraise the loaded firmware's integrity. Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com> Signed-off-by: Kees Cook <keescook@chromium.org>
* Remove spurious _H suffixes from ifdef commentsPaul Bolle2013-03-271-2/+2
| | | | | Signed-off-by: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
* ima: support new kernel module syscallMimi Zohar2012-12-141-0/+6
| | | | | | | | | | | | | | | | With the addition of the new kernel module syscall, which defines two arguments - a file descriptor to the kernel module and a pointer to a NULL terminated string of module arguments - it is now possible to measure and appraise kernel modules like any other file on the file system. This patch adds support to measure and appraise kernel modules in an extensible and consistent manner. To support filesystems without extended attribute support, additional patches could pass the signature as the first parameter. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
* ima: add ima_inode_setxattr/removexattr function and callsMimi Zohar2012-09-071-0/+17
| | | | | | | | | | | | | | | | | | | | | | | | Based on xattr_permission comments, the restriction to modify 'security' xattr is left up to the underlying fs or lsm. Ensure that not just anyone can modify or remove 'security.ima'. Changelog v1: - Unless IMA-APPRAISE is configured, use stub ima_inode_removexattr()/setxattr() functions. (Moved ima_inode_removexattr()/setxattr() to ima_appraise.c) Changelog: - take i_mutex to fix locking (Dmitry Kasatkin) - ima_reset_appraise_flags should only be called when modifying or removing the 'security.ima' xattr. Requires CAP_SYS_ADMIN privilege. (Incorporated fix from Roberto Sassu) - Even if allowed to update security.ima, reset the appraisal flags, forcing re-appraisal. - Replace CAP_MAC_ADMIN with CAP_SYS_ADMIN - static inline ima_inode_setxattr()/ima_inode_removexattr() stubs - ima_protect_xattr should be static Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
* ima: add inode_post_setattr callMimi Zohar2012-09-071-0/+10
| | | | | | | | | | | | Changing an inode's metadata may result in our not needing to appraise the file. In such cases, we must remove 'security.ima'. Changelog v1: - use ima_inode_post_setattr() stub function, if IMA_APPRAISE not configured Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com> Acked-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
* integrity: move ima inode integrity data managementMimi Zohar2011-07-181-13/+0
| | | | | | | | | | | | | | | | | | | | Move the inode integrity data(iint) management up to the integrity directory in order to share the iint among the different integrity models. Changelog: - don't define MAX_DIGEST_SIZE - rename several globally visible 'ima_' prefixed functions, structs, locks, etc to 'integrity_' - replace '20' with SHA1_DIGEST_SIZE - reflect location change in appropriate Kconfig and Makefiles - remove unnecessary initialization of iint_initialized to 0 - rebased on current ima_iint.c - define integrity_iint_store/lock as static There should be no other functional changes. Signed-off-by: Mimi Zohar <zohar@us.ibm.com> Acked-by: Serge Hallyn <serge.hallyn@ubuntu.com>
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