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* Merge tag 'devicetree-for-5.13' of ↵Linus Torvalds2021-04-292-10/+3
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux Pull devicetree updates from Rob Herring: - Refactor powerpc and arm64 kexec DT handling to common code. This enables IMA on arm64. - Add kbuild support for applying DT overlays at build time. The first user are the DT unittests. - Fix kerneldoc formatting and W=1 warnings in drivers/of/ - Fix handling 64-bit flag on PCI resources - Bump dtschema version required to v2021.2.1 - Enable undocumented compatible checks for dtbs_check. This allows tracking of missing binding schemas. - DT docs improvements. Regroup the DT docs and add the example schema and DT kernel ABI docs to the doc build. - Convert Broadcom Bluetooth and video-mux bindings to schema - Add QCom sm8250 Venus video codec binding schema - Add vendor prefixes for AESOP, YIC System Co., Ltd, and Siliconfile Technologies Inc. - Cleanup of DT schema type references on common properties and standard unit properties * tag 'devicetree-for-5.13' of git://git.kernel.org/pub/scm/linux/kernel/git/robh/linux: (64 commits) powerpc: If kexec_build_elf_info() fails return immediately from elf64_load() powerpc: Free fdt on error in elf64_load() of: overlay: Fix kerneldoc warning in of_overlay_remove() of: linux/of.h: fix kernel-doc warnings of/pci: Add IORESOURCE_MEM_64 to resource flags for 64-bit memory addresses dt-bindings: bcm4329-fmac: add optional brcm,ccode-map docs: dt: update writing-schema.rst references dt-bindings: media: venus: Add sm8250 dt schema of: base: Fix spelling issue with function param 'prop' docs: dt: Add DT API documentation of: Add missing 'Return' section in kerneldoc comments of: Fix kerneldoc output formatting docs: dt: Group DT docs into relevant sub-sections docs: dt: Make 'Devicetree' wording more consistent docs: dt: writing-schema: Include the example schema in the doc build docs: dt: writing-schema: Remove spurious indentation dt-bindings: Fix reference in submitting-patches.rst to the DT ABI doc dt-bindings: ddr: Add optional manufacturer and revision ID to LPDDR3 dt-bindings: media: video-interfaces: Drop the example devicetree: bindings: clock: Minor typo fix in the file armada3700-tbg-clock.txt ...
| * powerpc: Move arch independent ima kexec functions to drivers/of/kexec.cLakshmi Ramasubramanian2021-03-082-4/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
| * powerpc: Move ima buffer fields to struct kimageLakshmi Ramasubramanian2021-03-081-6/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The fields ima_buffer_addr and ima_buffer_size in "struct kimage_arch" for powerpc are used to carry forward the IMA measurement list across kexec system call. These fields are not architecture specific, but are currently limited to powerpc. arch_ima_add_kexec_buffer() defined in "arch/powerpc/kexec/ima.c" sets ima_buffer_addr and ima_buffer_size for the kexec system call. This function does not have architecture specific code, but is currently limited to powerpc. Move ima_buffer_addr and ima_buffer_size to "struct kimage". Set ima_buffer_addr and ima_buffer_size in ima_add_kexec_buffer() in security/integrity/ima/ima_kexec.c. 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> Suggested-by: Will Deacon <will@kernel.org> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Signed-off-by: Rob Herring <robh@kernel.org> Link: https://lore.kernel.org/r/20210221174930.27324-9-nramas@linux.microsoft.com
* | lsm: separate security_task_getsecid() into subjective and objective variantsPaul Moore2021-03-222-8/+8
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Of the three LSMs that implement the security_task_getsecid() LSM hook, all three LSMs provide the task's objective security credentials. This turns out to be unfortunate as most of the hook's callers seem to expect the task's subjective credentials, although a small handful of callers do correctly expect the objective credentials. This patch is the first step towards fixing the problem: it splits the existing security_task_getsecid() hook into two variants, one for the subjective creds, one for the objective creds. void security_task_getsecid_subj(struct task_struct *p, u32 *secid); void security_task_getsecid_obj(struct task_struct *p, u32 *secid); While this patch does fix all of the callers to use the correct variant, in order to keep this patch focused on the callers and to ease review, the LSMs continue to use the same implementation for both hooks. The net effect is that this patch should not change the behavior of the kernel in any way, it will be up to the latter LSM specific patches in this series to change the hook implementations and return the correct credentials. Acked-by: Mimi Zohar <zohar@linux.ibm.com> (IMA) Acked-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
* Merge tag 'keys-misc-20210126' of ↵Linus Torvalds2021-02-241-3/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull keyring updates from David Howells: "Here's a set of minor keyrings fixes/cleanups that I've collected from various people for the upcoming merge window. A couple of them might, in theory, be visible to userspace: - Make blacklist_vet_description() reject uppercase letters as they don't match the all-lowercase hex string generated for a blacklist search. This may want reconsideration in the future, but, currently, you can't add to the blacklist keyring from userspace and the only source of blacklist keys generates lowercase descriptions. - Fix blacklist_init() to use a new KEY_ALLOC_* flag to indicate that it wants KEY_FLAG_KEEP to be set rather than passing KEY_FLAG_KEEP into keyring_alloc() as KEY_FLAG_KEEP isn't a valid alloc flag. This isn't currently a problem as the blacklist keyring isn't currently writable by userspace. The rest of the patches are cleanups and I don't think they should have any visible effect" * tag 'keys-misc-20210126' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: watch_queue: rectify kernel-doc for init_watch() certs: Replace K{U,G}IDT_INIT() with GLOBAL_ROOT_{U,G}ID certs: Fix blacklist flag type confusion PKCS#7: Fix missing include certs: Fix blacklisted hexadecimal hash string check certs/blacklist: fix kernel doc interface issue crypto: public_key: Remove redundant header file from public_key.h keys: remove trailing semicolon in macro definition crypto: pkcs7: Use match_string() helper to simplify the code PKCS#7: drop function from kernel-doc pkcs7_validate_trust_one encrypted-keys: Replace HTTP links with HTTPS ones crypto: asymmetric_keys: fix some comments in pkcs7_parser.h KEYS: remove redundant memset security: keys: delete repeated words in comments KEYS: asymmetric: Fix kerneldoc security/keys: use kvfree_sensitive() watch_queue: Drop references to /dev/watch_queue keys: Remove outdated __user annotations security: keys: Fix fall-through warnings for Clang
| * certs: Fix blacklist flag type confusionDavid Howells2021-01-211-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | KEY_FLAG_KEEP is not meant to be passed to keyring_alloc() or key_alloc(), as these only take KEY_ALLOC_* flags. KEY_FLAG_KEEP has the same value as KEY_ALLOC_BYPASS_RESTRICTION, but fortunately only key_create_or_update() uses it. LSMs using the key_alloc hook don't check that flag. KEY_FLAG_KEEP is then ignored but fortunately (again) the root user cannot write to the blacklist keyring, so it is not possible to remove a key/hash from it. Fix this by adding a KEY_ALLOC_SET_KEEP flag that tells key_alloc() to set KEY_FLAG_KEEP on the new key. blacklist_init() can then, correctly, pass this to keyring_alloc(). We can also use this in ima_mok_init() rather than setting the flag manually. Note that this doesn't fix an observable bug with the current implementation but it is required to allow addition of new hashes to the blacklist in the future without making it possible for them to be removed. Fixes: 734114f8782f ("KEYS: Add a system blacklist keyring") Reported-by: Mickaël Salaün <mic@linux.microsoft.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Mickaël Salaün <mic@linux.microsoft.com> cc: Mimi Zohar <zohar@linux.vnet.ibm.com> Cc: David Woodhouse <dwmw2@infradead.org>
* | Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds2021-02-237-46/+73
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Brauner2021-01-247-40/+68
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | xattr: handle idmapped mountsTycho Andersen2021-01-241-4/+4
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | When interacting with extended attributes the vfs verifies that the caller is privileged over the inode with which the extended attribute is associated. For posix access and posix default extended attributes a uid or gid can be stored on-disk. Let the functions handle posix extended attributes on idmapped mounts. If the inode is accessed through an idmapped mount we need to map it according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. This has no effect for e.g. security xattrs since they don't store uids or gids and don't perform permission checks on them like posix acls do. Link: https://lore.kernel.org/r/20210121131959.646623-10-christian.brauner@ubuntu.com Cc: Christoph Hellwig <hch@lst.de> Cc: David Howells <dhowells@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: linux-fsdevel@vger.kernel.org Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Tycho Andersen <tycho@tycho.pizza> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
* | Merge branch 'ima-kexec-fixes' into next-integrityMimi Zohar2021-02-101-0/+3
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| * | ima: Free IMA measurement buffer after kexec syscallLakshmi Ramasubramanian2021-02-101-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | IMA allocates kernel virtual memory to carry forward the measurement list, from the current kernel to the next kernel on kexec system call, in ima_add_kexec_buffer() function. This buffer is not freed before completing the kexec system call resulting in memory leak. Add ima_buffer field in "struct kimage" to store the virtual address of the buffer allocated for the IMA measurement list. Free the memory allocated for the IMA measurement list in kimage_file_post_load_cleanup() function. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Thiago Jung Bauermann <bauerman@linux.ibm.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * | ima: Free IMA measurement buffer on errorLakshmi Ramasubramanian2021-02-101-0/+1
| |/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | IMA allocates kernel virtual memory to carry forward the measurement list, from the current kernel to the next kernel on kexec system call, in ima_add_kexec_buffer() function. In error code paths this memory is not freed resulting in memory leak. Free the memory allocated for the IMA measurement list in the error code paths in ima_add_kexec_buffer() function. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Tyler Hicks <tyhicks@linux.microsoft.com> Fixes: 7b8589cc29e7 ("ima: on soft reboot, save the measurement list") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* | IMA: Measure kernel version in early bootRaphael Gianotti2021-01-271-0/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The integrity of a kernel can be verified by the boot loader on cold boot, and during kexec, by the current running kernel, before it is loaded. However, it is still possible that the new kernel being loaded is older than the current kernel, and/or has known vulnerabilities. Therefore, it is imperative that an attestation service be able to verify the version of the kernel being loaded on the client, from cold boot and subsequent kexec system calls, ensuring that only kernels with versions known to be good are loaded. Measure the kernel version using ima_measure_critical_data() early on in the boot sequence, reducing the chances of known kernel vulnerabilities being exploited. With IMA being part of the kernel, this overall approach makes the measurement itself more trustworthy. To enable measuring the kernel version "ima_policy=critical_data" needs to be added to the kernel command line arguments. For example, BOOT_IMAGE=/boot/vmlinuz-5.11.0-rc3+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset ima_policy=critical_data If runtime measurement of the kernel version is ever needed, the following should be added to /etc/ima/ima-policy: measure func=CRITICAL_DATA label=kernel_info To extract the measured data after boot, the following command can be used: grep -m 1 "kernel_version" \ /sys/kernel/security/integrity/ima/ascii_runtime_measurements Sample output from the command above: 10 a8297d408e9d5155728b619761d0dd4cedf5ef5f ima-buf sha256:5660e19945be0119bc19cbbf8d9c33a09935ab5d30dad48aa11f879c67d70988 kernel_version 352e31312e302d7263332d31363138372d676564623634666537383234342d6469727479 The above hex-ascii string corresponds to the kernel version (e.g. xxd -r -p): 5.11.0-rc3-16187-gedb64fe78244-dirty Signed-off-by: Raphael Gianotti <raphgi@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* | IMA: define a builtin critical data measurement policyLakshmi Ramasubramanian2021-01-151-0/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | Define a new critical data builtin policy to allow measuring early kernel integrity critical data before a custom IMA policy is loaded. Update the documentation on kernel parameters to document the new critical data builtin policy. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* | IMA: extend critical data hook to limit the measurement based on a labelTushar Sugandhi2021-01-151-3/+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: limit critical data measurement based on a labelTushar Sugandhi2021-01-151-3/+34
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Integrity critical data may belong to a single subsystem or it may arise from cross subsystem interaction. Currently there is no mechanism to group or limit the data based on certain label. Limiting and grouping critical data based on a label would make it flexible and configurable to measure. Define "label:=", a new IMA policy condition, for the IMA func CRITICAL_DATA to allow grouping and limiting measurement of integrity critical data. Limit the measurement to the labels that are specified in the IMA policy - CRITICAL_DATA+"label:=". If "label:=" is not provided with the func CRITICAL_DATA, measure all the input 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>
* | IMA: add policy rule to measure critical dataTushar Sugandhi2021-01-151-4/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | A new IMA policy rule is needed for the IMA hook ima_measure_critical_data() and the corresponding func CRITICAL_DATA for measuring the input buffer. The policy rule should ensure the buffer would get measured only when the policy rule allows the action. The policy rule should also support the necessary constraints (flags etc.) for integrity critical buffer data measurements. Add policy rule support for measuring 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>
* | IMA: define a hook to measure kernel integrity critical dataTushar Sugandhi2021-01-153-1/+26
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | IMA: add support to measure buffer data hashTushar Sugandhi2021-01-155-9/+30
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: generalize keyring specific measurement constructsTushar Sugandhi2021-01-154-26/+35
|/ | | | | | | | | | | | | | 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>
* Merge tag 'efi_updates_for_v5.11' of ↵Linus Torvalds2020-12-242-0/+77
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull EFI updates from Borislav Petkov: "These got delayed due to a last minute ia64 build issue which got fixed in the meantime. EFI updates collected by Ard Biesheuvel: - Don't move BSS section around pointlessly in the x86 decompressor - Refactor helper for discovering the EFI secure boot mode - Wire up EFI secure boot to IMA for arm64 - Some fixes for the capsule loader - Expose the RT_PROP table via the EFI test module - Relax DT and kernel placement restrictions on ARM with a few followup fixes: - fix the build breakage on IA64 caused by recent capsule loader changes - suppress a type mismatch build warning in the expansion of EFI_PHYS_ALIGN on ARM" * tag 'efi_updates_for_v5.11' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: efi: arm: force use of unsigned type for EFI_PHYS_ALIGN efi: ia64: disable the capsule loader efi: stub: get rid of efi_get_max_fdt_addr() efi/efi_test: read RuntimeServicesSupported efi: arm: reduce minimum alignment of uncompressed kernel efi: capsule: clean scatter-gather entries from the D-cache efi: capsule: use atomic kmap for transient sglist mappings efi: x86/xen: switch to efi_get_secureboot_mode helper arm64/ima: add ima_arch support ima: generalize x86/EFI arch glue for other EFI architectures efi: generalize efi_get_secureboot efi/libstub: EFI_GENERIC_STUB_INITRD_CMDLINE_LOADER should not default to yes efi/x86: Only copy the compressed kernel image in efi_relocate_kernel() efi/libstub/x86: simplify efi_is_native()
| * ima: generalize x86/EFI arch glue for other EFI architecturesChester Lin2020-11-062-0/+77
| | | | | | | | | | | | | | | | | | | | Move the x86 IMA arch code into security/integrity/ima/ima_efi.c, so that we will be able to wire it up for arm64 in a future patch. Co-developed-by: Chester Lin <clin@suse.com> Signed-off-by: Chester Lin <clin@suse.com> Acked-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
* | Merge tag 'integrity-v5.11' of ↵Linus Torvalds2020-12-166-37/+54
|\ \ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Don't modify file descriptor mode on the flyRoberto Sassu2020-11-291-15/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Commit a408e4a86b36b ("ima: open a new file instance if no read permissions") already introduced a second open to measure a file when the original file descriptor does not allow it. However, it didn't remove the existing method of changing the mode of the original file descriptor, which is still necessary if the current process does not have enough privileges to open a new one. Changing the mode isn't really an option, as the filesystem might need to do preliminary steps to make the read possible. Thus, this patch removes the code and keeps the second open as the only option to measure a file when it is unreadable with the original file descriptor. Cc: <stable@vger.kernel.org> # 4.20.x: 0014cc04e8ec0 ima: Set file->f_mode Fixes: 2fe5d6def1672 ("ima: integrity appraisal extension") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * | ima: select ima-buf template for buffer measurementLakshmi Ramasubramanian2020-11-204-16/+37
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
| * | ima: defer arch_ima_get_secureboot() call to IMA init timeArd Biesheuvel2020-11-022-6/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 Singh2020-11-261-24/+54
|/ / | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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
* / ima: Replace zero-length array with flexible-array memberGustavo A. R. Silva2020-10-291-1/+1
|/ | | | | | | | | | | | There is a regular need in the kernel to provide a way to declare having a dynamically sized set of trailing elements in a structure. Kernel code should always use “flexible array members”[1] for these cases. The older style of one-element or zero-length arrays should no longer be used[2]. [1] https://en.wikipedia.org/wiki/Flexible_array_member [2] https://www.kernel.org/doc/html/v5.9-rc1/process/deprecated.html#zero-length-and-one-element-arrays Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* Merge tag 'integrity-v5.10' of ↵Linus Torvalds2020-10-165-64/+143
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity updates from Mimi Zohar: "Continuing IMA policy rule cleanup and validation in particular for measuring keys, adding/removing/updating informational and error messages (e.g. "ima_appraise" boot command line option), and other bug fixes (e.g. minimal data size validation before use, return code and NULL pointer checking)" * tag 'integrity-v5.10' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: ima: Fix NULL pointer dereference in ima_file_hash evm: Check size of security.evm before using it ima: Remove semicolon at the end of ima_get_binary_runtime_size() ima: Don't ignore errors from crypto_shash_update() ima: Use kmemdup rather than kmalloc+memcpy integrity: include keyring name for unknown key request ima: limit secure boot feedback scope for appraise integrity: invalid kernel parameters feedback ima: add check for enforced appraise option integrity: Use current_uid() in integrity_audit_message() ima: Fail rule parsing when asymmetric key measurement isn't supportable ima: Pre-parse the list of keyrings in a KEY_CHECK rule
| * ima: Fix NULL pointer dereference in ima_file_hashKP Singh2020-09-161-0/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | ima_file_hash can be called when there is no iint->ima_hash available even though the inode exists in the integrity cache. It is fairly common for a file to not have a hash. (e.g. an mknodat, prior to the file being closed). Another example where this can happen (suggested by Jann Horn): Process A does: while(1) { unlink("/tmp/imafoo"); fd = open("/tmp/imafoo", O_RDWR|O_CREAT|O_TRUNC, 0700); if (fd == -1) { perror("open"); continue; } write(fd, "A", 1); close(fd); } and Process B does: while (1) { int fd = open("/tmp/imafoo", O_RDONLY); if (fd == -1) continue; char *mapping = mmap(NULL, 0x1000, PROT_READ|PROT_EXEC, MAP_PRIVATE, fd, 0); if (mapping != MAP_FAILED) munmap(mapping, 0x1000); close(fd); } Due to the race to get the iint->mutex between ima_file_hash and process_measurement iint->ima_hash could still be NULL. Fixes: 6beea7afcc72 ("ima: add the ability to query the cached hash of a given file") Signed-off-by: KP Singh <kpsingh@google.com> Reviewed-by: Florent Revest <revest@chromium.org> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * ima: Remove semicolon at the end of ima_get_binary_runtime_size()Roberto Sassu2020-09-151-1/+1
| | | | | | | | | | | | | | | | | | | | This patch removes the unnecessary semicolon at the end of ima_get_binary_runtime_size(). Cc: stable@vger.kernel.org Fixes: d158847ae89a2 ("ima: maintain memory size needed for serializing the measurement list") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * ima: Don't ignore errors from crypto_shash_update()Roberto Sassu2020-09-151-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | Errors returned by crypto_shash_update() are not checked in ima_calc_boot_aggregate_tfm() and thus can be overwritten at the next iteration of the loop. This patch adds a check after calling crypto_shash_update() and returns immediately if the result is not zero. Cc: stable@vger.kernel.org Fixes: 3323eec921efd ("integrity: IMA as an integrity service provider") Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * ima: Use kmemdup rather than kmalloc+memcpyAlex Dewar2020-09-151-5/+4
| | | | | | | | | | | | | | Issue identified with Coccinelle. Signed-off-by: Alex Dewar <alex.dewar90@gmail.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * ima: limit secure boot feedback scope for appraiseBruno Meneguele2020-09-101-9/+16
| | | | | | | | | | | | | | | | | | Only emit an unknown/invalid message when setting the IMA appraise mode to anything other than "enforce", when secureboot is enabled. Signed-off-by: Bruno Meneguele <bmeneg@redhat.com> [zohar@linux.ibm.com: updated commit message] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * integrity: invalid kernel parameters feedbackBruno Meneguele2020-09-093-4/+13
| | | | | | | | | | | | | | | | Don't silently ignore unknown or invalid ima_{policy,appraise,hash} and evm kernel boot command line options. Signed-off-by: Bruno Meneguele <bmeneg@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * ima: add check for enforced appraise optionBruno Meneguele2020-09-091-0/+2
| | | | | | | | | | | | | | | | | | | | The "enforce" string is allowed as an option for ima_appraise= kernel paramenter per kernel-paramenters.txt and should be considered on the parameter setup checking as a matter of completeness. Also it allows futher checking on the options being passed by the user. Signed-off-by: Bruno Meneguele <bmeneg@redhat.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * ima: Fail rule parsing when asymmetric key measurement isn't supportableTyler Hicks2020-08-311-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Measuring keys is currently only supported for asymmetric keys. In the future, this might change. For now, the "func=KEY_CHECK" and "keyrings=" options are only appropriate when CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS is enabled. Make this clear at policy load so that IMA policy authors don't assume that these policy language constructs are supported. Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") Fixes: 5808611cccb2 ("IMA: Add KEY_CHECK func to measure keys") Suggested-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Reviewed-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
| * ima: Pre-parse the list of keyrings in a KEY_CHECK ruleTyler Hicks2020-08-311-45/+93
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The ima_keyrings buffer was used as a work buffer for strsep()-based parsing of the "keyrings=" option of an IMA policy rule. This parsing was re-performed each time an asymmetric key was added to a kernel keyring for each loaded policy rule that contained a "keyrings=" option. An example rule specifying this option is: measure func=KEY_CHECK keyrings=a|b|c The rule says to measure asymmetric keys added to any of the kernel keyrings named "a", "b", or "c". The size of the buffer size was equal to the size of the largest "keyrings=" value seen in a previously loaded rule (5 + 1 for the NUL-terminator in the previous example) and the buffer was pre-allocated at the time of policy load. The pre-allocated buffer approach suffered from a couple bugs: 1) There was no locking around the use of the buffer so concurrent key add operations, to two different keyrings, would result in the strsep() loop of ima_match_keyring() to modify the buffer at the same time. This resulted in unexpected results from ima_match_keyring() and, therefore, could cause unintended keys to be measured or keys to not be measured when IMA policy intended for them to be measured. 2) If the kstrdup() that initialized entry->keyrings in ima_parse_rule() failed, the ima_keyrings buffer was freed and set to NULL even when a valid KEY_CHECK rule was previously loaded. The next KEY_CHECK event would trigger a call to strcpy() with a NULL destination pointer and crash the kernel. Remove the need for a pre-allocated global buffer by parsing the list of keyrings in a KEY_CHECK rule at the time of policy load. The ima_rule_entry will contain an array of string pointers which point to the name of each keyring specified in the rule. No string processing needs to happen at the time of asymmetric key add so iterating through the list and doing a string comparison is all that's required at the time of policy check. In the process of changing how the "keyrings=" policy option is handled, a couple additional bugs were fixed: 1) The rule parser accepted rules containing invalid "keyrings=" values such as "a|b||c", "a|b|", or simply "|". 2) The /sys/kernel/security/ima/policy file did not display the entire "keyrings=" value if the list of keyrings was longer than what could fit in the fixed size tbuf buffer in ima_policy_show(). Fixes: 5c7bac9fb2c5 ("IMA: pre-allocate buffer to hold keyrings string") Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Reviewed-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
* | fs/kernel_file_read: Add "offset" arg for partial readsKees Cook2020-10-051-1/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | To perform partial reads, callers of kernel_read_file*() must have a non-NULL file_size argument and a preallocated buffer. The new "offset" argument can then be used to seek to specific locations in the file to fill the buffer to, at most, "buf_size" per call. Where possible, the LSM hooks can report whether a full file has been read or not so that the contents can be reasoned about. Signed-off-by: Kees Cook <keescook@chromium.org> Link: https://lore.kernel.org/r/20201002173828.2099543-14-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | IMA: Add support for file reads without contentsScott Branden2020-10-051-6/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | When the kernel_read_file LSM hook is called with contents=false, IMA can appraise the file directly, without requiring a filled buffer. When such a buffer is available, though, IMA can continue to use it instead of forcing a double read here. Signed-off-by: Scott Branden <scott.branden@broadcom.com> Link: https://lore.kernel.org/lkml/20200706232309.12010-10-scott.branden@broadcom.com/ Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/r/20201002173828.2099543-13-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | LSM: Add "contents" flag to kernel_read_file hookKees Cook2020-10-051-1/+9
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | firmware_loader: Use security_post_load_data()Kees Cook2020-10-051-10/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that security_post_load_data() is wired up, use it instead of the NULL file argument style of security_post_read_file(), and update the security_kernel_load_data() call to indicate that a security_kernel_post_load_data() call is expected. Wire up the IMA check to match earlier logic. Perhaps a generalized change to ima_post_load_data() might look something like this: return process_buffer_measurement(buf, size, kernel_load_data_id_str(load_id), read_idmap[load_id] ?: FILE_CHECK, 0, NULL); Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Link: https://lore.kernel.org/r/20201002173828.2099543-10-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | LSM: Introduce kernel_post_load_data() hookKees Cook2020-10-051-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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: Add file_size output argumentKees Cook2020-10-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for adding partial read support, add an optional output argument to kernel_read_file*() that reports the file size so callers can reason more easily about their reading progress. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Acked-by: Scott Branden <scott.branden@broadcom.com> Link: https://lore.kernel.org/r/20201002173828.2099543-8-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | fs/kernel_read_file: Switch buffer size arg to size_tKees Cook2020-10-051-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for further refactoring of kernel_read_file*(), rename the "max_size" argument to the more accurate "buf_size", and correct its type to size_t. Add kerndoc to explain the specifics of how the arguments will be used. Note that with buf_size now size_t, it can no longer be negative (and was never called with a negative value). Adjust callers to use it as a "maximum size" when *buf is NULL. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Acked-by: Scott Branden <scott.branden@broadcom.com> Link: https://lore.kernel.org/r/20201002173828.2099543-7-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | fs/kernel_read_file: Remove redundant size argumentKees Cook2020-10-051-2/+4
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | In preparation for refactoring kernel_read_file*(), remove the redundant "size" argument which is not needed: it can be included in the return code, with callers adjusted. (VFS reads already cannot be larger than INT_MAX.) Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Acked-by: Scott Branden <scott.branden@broadcom.com> Link: https://lore.kernel.org/r/20201002173828.2099543-6-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | fs/kernel_read_file: Split into separate include fileScott Branden2020-10-053-0/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | fs/kernel_read_file: Remove FIRMWARE_PREALLOC_BUFFER enumKees Cook2020-10-052-5/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | FIRMWARE_PREALLOC_BUFFER is a "how", not a "what", and confuses the LSMs that are interested in filtering between types of things. The "how" should be an internal detail made uninteresting to the LSMs. Fixes: a098ecd2fa7d ("firmware: support loading into a pre-allocated buffer") Fixes: fd90bc559bfb ("ima: based on policy verify firmware signatures (pre-allocated buffer)") Fixes: 4f0496d8ffa3 ("ima: based on policy warn about loading firmware (pre-allocated buffer)") Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Reviewed-by: Luis Chamberlain <mcgrof@kernel.org> Acked-by: Scott Branden <scott.branden@broadcom.com> Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/20201002173828.2099543-2-keescook@chromium.org Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva2020-08-243-7/+7
|/ | | | | | | | | | Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
* Merge tag 'for-v5.9' of ↵Linus Torvalds2020-08-114-4/+4
|\ | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "A couple of minor documentation updates only for this release" * tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: LSM: drop duplicated words in header file comments Replace HTTP links with HTTPS ones: security