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2021-02-24Merge tag 'keys-misc-20210126' of ↵Linus Torvalds8-21/+18
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Fix kerneldoc security/keys: use kvfree_sensitive() watch_queue: Drop references to /dev/watch_queue keys: Remove outdated __user annotations security: keys: Fix fall-through warnings for Clang
2021-02-24Merge tag 'idmapped-mounts-v5.12' of ↵Linus Torvalds18-115/+240
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 ...
2021-02-23Merge branch 'userns-for-v5.12' of ↵Linus Torvalds1-1/+11
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull user namespace update from Eric Biederman: "There are several pieces of active development, but only a single change made it through the gauntlet to be ready for v5.12. That change is tightening up the semantics of the v3 capabilities xattr. It is just short of being a bug-fix/security issue as no user space is known to even generate the problem case" * 'userns-for-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: capabilities: Don't allow writing ambiguous v3 file capabilities
2021-02-23Merge branch 'work.audit' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull RCU-safe common_lsm_audit() from Al Viro: "Make common_lsm_audit() non-blocking and usable from RCU pathwalk context. We don't really need to grab/drop dentry in there - rcu_read_lock() is enough. There's a couple of followups using that to simplify the logics in selinux, but those hadn't soaked in -next yet, so they'll have to go in next window" * 'work.audit' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: make dump_common_audit_data() safe to be called from RCU pathwalk new helper: d_find_alias_rcu()
2021-02-22Merge tag 'tpmdd-next-v5.12-rc1-v2' of ↵Linus Torvalds2-8/+36
git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd Pull tpm updates from Jarkko Sakkinen: "New features: - Cr50 I2C TPM driver - sysfs exports of PCR registers in TPM 2.0 chips Bug fixes: - bug fixes for tpm_tis driver, which had a racy wait for hardware state change to be ready to send a command to the TPM chip. The bug has existed already since 2006, but has only made itself known in recent past. This is the same as the "last time" :-) - Otherwise there's bunch of fixes for not as alarming regressions. I think the list is about the same as last time, except I added fixes for some disjoint bugs in trusted keys that I found some time ago" * tag 'tpmdd-next-v5.12-rc1-v2' of git://git.kernel.org/pub/scm/linux/kernel/git/jarkko/linux-tpmdd: KEYS: trusted: Reserve TPM for seal and unseal operations KEYS: trusted: Fix migratable=1 failing KEYS: trusted: Fix incorrect handling of tpm_get_random() tpm/ppi: Constify static struct attribute_group ABI: add sysfs description for tpm exports of PCR registers tpm: add sysfs exports for all banks of PCR registers keys: Update comment for restrict_link_by_key_or_keyring_chain tpm: Remove tpm_dev_wq_lock char: tpm: add i2c driver for cr50 tpm: Fix fall-through warnings for Clang tpm_tis: Clean up locality release tpm_tis: Fix check_locality for correct locality acquisition
2021-02-22Merge tag 'Smack-for-v5.12' of git://github.com/cschaufler/smack-nextLinus Torvalds1-2/+19
Pull smack updates from Casey Schaufler: "Bounds checking for writes to smackfs interfaces" * tag 'Smack-for-v5.12' of git://github.com/cschaufler/smack-next: smackfs: restrict bytes count in smackfs write functions
2021-02-22Merge tag 'integrity-v5.12' of ↵Linus Torvalds16-52/+301
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull IMA updates from Mimi Zohar: "New is IMA support for measuring kernel critical data, as per usual based on policy. The first example measures the in memory SELinux policy. The second example measures the kernel version. In addition are four bug fixes to address memory leaks and a missing 'static' function declaration" * tag 'integrity-v5.12' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: integrity: Make function integrity_add_key() static ima: Free IMA measurement buffer after kexec syscall ima: Free IMA measurement buffer on error IMA: Measure kernel version in early boot selinux: include a consumer of the new IMA critical data hook IMA: define a builtin critical data measurement policy IMA: extend critical data hook to limit the measurement based on a label IMA: limit critical data measurement based on a label IMA: add policy rule to measure critical data IMA: define a hook to measure kernel integrity critical data IMA: add support to measure buffer data hash IMA: generalize keyring specific measurement constructs evm: Fix memleak in init_desc
2021-02-22Merge tag 'selinux-pr-20210215' of ↵Linus Torvalds16-51/+141
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "We've got a good handful of patches for SELinux this time around; with everything passing the selinux-testsuite and applying cleanly to your tree as of a few minutes ago. The highlights are: - Add support for labeling anonymous inodes, and extend this new support to userfaultfd. - Fallback to SELinux genfs file labeling if the filesystem does not have xattr support. This is useful for virtiofs which can vary in its xattr support depending on the backing filesystem. - Classify and handle MPTCP the same as TCP in SELinux. - Ensure consistent behavior between inode_getxattr and inode_listsecurity when the SELinux policy is not loaded. This fixes a known problem with overlayfs. - A couple of patches to prune some unused variables from the SELinux code, mark private variables as static, and mark other variables as __ro_after_init or __read_mostly" * tag 'selinux-pr-20210215' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: fs: anon_inodes: rephrase to appropriate kernel-doc userfaultfd: use secure anon inodes for userfaultfd selinux: teach SELinux about anonymous inodes fs: add LSM-supporting anon-inode interface security: add inode_init_security_anon() LSM hook selinux: fall back to SECURITY_FS_USE_GENFS if no xattr support selinux: mark selinux_xfrm_refcount as __read_mostly selinux: mark some global variables __ro_after_init selinux: make selinuxfs_mount static selinux: drop the unnecessary aurule_callback variable selinux: remove unused global variables selinux: fix inconsistency between inode_getxattr and inode_listsecurity selinux: handle MPTCP consistently with TCP
2021-02-22Merge tag 'tomoyo-pr-20210215' of git://git.osdn.net/gitroot/tomoyo/tomoyo-test1Linus Torvalds3-25/+25
Pull tomoyo updates from Tetsuo Handa: "Detect kernel thread correctly, and ignore harmless data race" * tag 'tomoyo-pr-20210215' of git://git.osdn.net/gitroot/tomoyo/tomoyo-test1: tomoyo: recognize kernel threads correctly tomoyo: ignore data race while checking quota
2021-02-16KEYS: trusted: Reserve TPM for seal and unseal operationsJarkko Sakkinen1-4/+18
When TPM 2.0 trusted keys code was moved to the trusted keys subsystem, the operations were unwrapped from tpm_try_get_ops() and tpm_put_ops(), which are used to take temporarily the ownership of the TPM chip. The ownership is only taken inside tpm_send(), but this is not sufficient, as in the key load TPM2_CC_LOAD, TPM2_CC_UNSEAL and TPM2_FLUSH_CONTEXT need to be done as a one single atom. Take the TPM chip ownership before sending anything with tpm_try_get_ops() and tpm_put_ops(), and use tpm_transmit_cmd() to send TPM commands instead of tpm_send(), reverting back to the old behaviour. Fixes: 2e19e10131a0 ("KEYS: trusted: Move TPM2 trusted keys code") Reported-by: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: stable@vger.kernel.org Cc: David Howells <dhowells@redhat.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: Sumit Garg <sumit.garg@linaro.org> Acked-by Sumit Garg <sumit.garg@linaro.org> Tested-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2021-02-16KEYS: trusted: Fix migratable=1 failingJarkko Sakkinen1-1/+1
Consider the following transcript: $ keyctl add trusted kmk "new 32 blobauth=helloworld keyhandle=80000000 migratable=1" @u add_key: Invalid argument The documentation has the following description: migratable= 0|1 indicating permission to reseal to new PCR values, default 1 (resealing allowed) The consequence is that "migratable=1" should succeed. Fix this by allowing this condition to pass instead of return -EINVAL. [*] Documentation/security/keys/trusted-encrypted.rst Cc: stable@vger.kernel.org Cc: "James E.J. Bottomley" <jejb@linux.ibm.com> Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: David Howells <dhowells@redhat.com> Fixes: d00a1c72f7f4 ("keys: add new trusted key-type") Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org>
2021-02-16KEYS: trusted: Fix incorrect handling of tpm_get_random()Jarkko Sakkinen1-3/+17
When tpm_get_random() was introduced, it defined the following API for the return value: 1. A positive value tells how many bytes of random data was generated. 2. A negative value on error. However, in the call sites the API was used incorrectly, i.e. as it would only return negative values and otherwise zero. Returning he positive read counts to the user space does not make any possible sense. Fix this by returning -EIO when tpm_get_random() returns a positive value. Fixes: 41ab999c80f1 ("tpm: Move tpm_get_random api into the TPM device driver") Cc: stable@vger.kernel.org Cc: Mimi Zohar <zohar@linux.ibm.com> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: David Howells <dhowells@redhat.com> Cc: Kent Yoder <key@linux.vnet.ibm.com> Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
2021-02-12integrity: Make function integrity_add_key() staticWei Yongjun1-2/+2
The sparse tool complains as follows: security/integrity/digsig.c:146:12: warning: symbol 'integrity_add_key' was not declared. Should it be static? This function is not used outside of digsig.c, so this commit marks it static. Reported-by: Hulk Robot <hulkci@huawei.com> Fixes: 60740accf784 ("integrity: Load certs to the platform keyring") Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-02-11Merge branch 'ima-kexec-fixes' into next-integrityMimi Zohar1-0/+3
2021-02-10ima: Free IMA measurement buffer after kexec syscallLakshmi Ramasubramanian1-0/+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>
2021-02-10ima: Free IMA measurement buffer on errorLakshmi Ramasubramanian1-0/+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>
2021-02-03smackfs: restrict bytes count in smackfs write functionsSabyrzhan Tasbolatov1-2/+19
syzbot found WARNINGs in several smackfs write operations where bytes count is passed to memdup_user_nul which exceeds GFP MAX_ORDER. Check count size if bigger than PAGE_SIZE. Per smackfs doc, smk_write_net4addr accepts any label or -CIPSO, smk_write_net6addr accepts any label or -DELETE. I couldn't find any general rule for other label lengths except SMK_LABELLEN, SMK_LONGLABEL, SMK_CIPSOMAX which are documented. Let's constrain, in general, smackfs label lengths for PAGE_SIZE. Although fuzzer crashes write to smackfs/netlabel on 0x400000 length. Here is a quick way to reproduce the WARNING: python -c "print('A' * 0x400000)" > /sys/fs/smackfs/netlabel Reported-by: syzbot+a71a442385a0b2815497@syzkaller.appspotmail.com Signed-off-by: Sabyrzhan Tasbolatov <snovitoll@gmail.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2021-02-01tomoyo: recognize kernel threads correctlyTetsuo Handa1-1/+1
Commit db68ce10c4f0a27c ("new helper: uaccess_kernel()") replaced segment_eq(get_fs(), KERNEL_DS) with uaccess_kernel(). But the correct method for tomoyo to check whether current is a kernel thread in order to assume that kernel threads are privileged for socket operations was (current->flags & PF_KTHREAD). Now that uaccess_kernel() became 0 on x86, tomoyo has to fix this problem. Do like commit 942cb357ae7d9249 ("Smack: Handle io_uring kernel thread privileges") does. Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2021-02-01tomoyo: ignore data race while checking quotaTetsuo Handa3-24/+24
syzbot is reporting that tomoyo's quota check is racy [1]. But this check is tolerant of some degree of inaccuracy. Thus, teach KCSAN to ignore this data race. [1] https://syzkaller.appspot.com/bug?id=999533deec7ba6337f8aa25d8bd1a4d5f7e50476 Reported-by: syzbot <syzbot+0789a72b46fd91431bd8@syzkaller.appspotmail.com> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2021-01-28cap: fix conversions on getxattrMiklos Szeredi1-24/+43
If a capability is stored on disk in v2 format cap_inode_getsecurity() will currently return in v2 format unconditionally. This is wrong: v2 cap should be equivalent to a v3 cap with zero rootid, and so the same conversions performed on it. If the rootid cannot be mapped, v3 is returned unconverted. Fix this so that both v2 and v3 return -EOVERFLOW if the rootid (or the owner of the fs user namespace in case of v2) cannot be mapped into the current user namespace. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
2021-01-27IMA: Measure kernel version in early bootRaphael Gianotti1-0/+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>
2021-01-24ima: handle idmapped mountsChristian Brauner7-40/+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>
2021-01-24apparmor: handle idmapped mountsChristian Brauner3-10/+24
The i_uid and i_gid are mostly used when logging for AppArmor. This is broken in a bunch of places where the global root id is reported instead of the i_uid or i_gid of the file. Nonetheless, be kind and log the mapped inode if we're coming from an idmapped mount. 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/20210121131959.646623-26-christian.brauner@ubuntu.com Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24fs: make helpers idmap mount awareChristian Brauner2-2/+3
Extend some inode methods with an additional user namespace argument. A filesystem that is aware of idmapped mounts will receive the user namespace the mount has been marked with. This can be used for additional permission checking and also to enable filesystems to translate between uids and gids if they need to. We have implemented all relevant helpers in earlier patches. As requested we simply extend the exisiting inode method instead of introducing new ones. This is a little more code churn but it's mostly mechanical and doesnt't leave us with additional inode methods. Link: https://lore.kernel.org/r/20210121131959.646623-25-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> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24commoncap: handle idmapped mountsChristian Brauner4-37/+84
When interacting with user namespace and non-user namespace aware filesystem capabilities the vfs will perform various security checks to determine whether or not the filesystem capabilities can be used by the caller, whether they need to be removed and so on. The main infrastructure for this resides in the capability codepaths but they are called through the LSM security infrastructure even though they are not technically an LSM or optional. This extends the existing security hooks security_inode_removexattr(), security_inode_killpriv(), security_inode_getsecurity() to pass down the mount's user namespace and makes them aware of idmapped mounts. In order to actually get filesystem capabilities from disk the capability infrastructure exposes the get_vfs_caps_from_disk() helper. For user namespace aware filesystem capabilities a root uid is stored alongside the capabilities. In order to determine whether the caller can make use of the filesystem capability or whether it needs to be ignored it is translated according to the superblock's user namespace. If it can be translated to uid 0 according to that id mapping the caller can use the filesystem capabilities stored on disk. If we are accessing the inode that holds the filesystem capabilities through an idmapped mount we map the root uid according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts: reading filesystem caps from disk enforces that the root uid associated with the filesystem capability must have a mapping in the superblock's user namespace and that the caller is either in the same user namespace or is a descendant of the superblock's user namespace. For filesystems that are mountable inside user namespace the caller can just mount the filesystem and won't usually need to idmap it. If they do want to idmap it they can create an idmapped mount and mark it with a user namespace they created and which is thus a descendant of s_user_ns. For filesystems that are not mountable inside user namespaces the descendant rule is trivially true because the s_user_ns will be the initial user namespace. 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/20210121131959.646623-11-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> Acked-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24xattr: handle idmapped mountsTycho Andersen7-20/+24
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>
2021-01-24acl: handle idmapped mountsChristian Brauner1-7/+38
The posix acl permission checking helpers determine whether a caller is privileged over an inode according to the acls associated with the inode. Add helpers that make it possible to handle acls on idmapped mounts. The vfs and the filesystems targeted by this first iteration make use of posix_acl_fix_xattr_from_user() and posix_acl_fix_xattr_to_user() to translate basic posix access and default permissions such as the ACL_USER and ACL_GROUP type according to the initial user namespace (or the superblock's user namespace) to and from the caller's current user namespace. Adapt these two helpers to handle idmapped mounts whereby we either map from or into the mount's user namespace depending on in which direction we're translating. Similarly, cap_convert_nscap() is used by the vfs to translate user namespace and non-user namespace aware filesystem capabilities from the superblock's user namespace to the caller's user namespace. Enable it to handle idmapped mounts by accounting for the mount's user namespace. In addition the fileystems targeted in the first iteration of this patch series make use of the posix_acl_chmod() and, posix_acl_update_mode() helpers. Both helpers perform permission checks on the target inode. Let them handle idmapped mounts. These two helpers are called when posix acls are set by the respective filesystems to handle this case we extend the ->set() method to take an additional user namespace argument to pass the mount's user namespace down. Link: https://lore.kernel.org/r/20210121131959.646623-9-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> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24inode: make init and permission helpers idmapped mount awareChristian Brauner1-2/+2
The inode_owner_or_capable() helper determines whether the caller is the owner of the inode or is capable with respect to that inode. Allow it to handle idmapped mounts. If the inode is accessed through an idmapped mount it according to the mount's user namespace. Afterwards the checks are identical to non-idmapped mounts. If the initial user namespace is passed nothing changes so non-idmapped mounts will see identical behavior as before. Similarly, allow the inode_init_owner() helper to handle idmapped mounts. It initializes a new inode on idmapped mounts by mapping the fsuid and fsgid of the caller from the mount's user namespace. 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/20210121131959.646623-7-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: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-24capability: handle idmapped mountsChristian Brauner1-2/+3
In order to determine whether a caller holds privilege over a given inode the capability framework exposes the two helpers privileged_wrt_inode_uidgid() and capable_wrt_inode_uidgid(). The former verifies that the inode has a mapping in the caller's user namespace and the latter additionally verifies that the caller has the requested capability in their current user namespace. If the inode is accessed through an idmapped mount map it into the mount's user namespace. Afterwards the checks are identical to non-idmapped inodes. If the initial user namespace is passed all operations are a nop so non-idmapped mounts will not see a change in behavior. Link: https://lore.kernel.org/r/20210121131959.646623-5-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> Acked-by: Serge Hallyn <serge@hallyn.com> Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
2021-01-21certs: Fix blacklist flag type confusionDavid Howells2-3/+4
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>
2021-01-21KEYS: remove redundant memsetTom Rix1-2/+0
Reviewing use of memset in keyctl_pkey.c keyctl_pkey_params_get prologue code to set params up memset(params, 0, sizeof(*params)); params->encoding = "raw"; keyctl_pkey_query has the same prologue and calls keyctl_pkey_params_get. So remove the prologue. Signed-off-by: Tom Rix <trix@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
2021-01-21security: keys: delete repeated words in commentsRandy Dunlap2-3/+3
Drop repeated words in comments. {to, will, the} Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Ben Boeckel <mathstuf@gmail.com> Cc: keyrings@vger.kernel.org Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org
2021-01-21security/keys: use kvfree_sensitive()Denis Efremov1-6/+3
Use kvfree_sensitive() instead of open-coding it. Signed-off-by: Denis Efremov <efremov@linux.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
2021-01-21watch_queue: Drop references to /dev/watch_queueGabriel Krisman Bertazi1-4/+4
The merged API doesn't use a watch_queue device, but instead relies on pipes, so let the documentation reflect that. Fixes: f7e47677e39a ("watch_queue: Add a key/keyring notification facility") Signed-off-by: Gabriel Krisman Bertazi <krisman@collabora.com> Signed-off-by: David Howells <dhowells@redhat.com> Acked-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
2021-01-21keys: Remove outdated __user annotationsJann Horn1-3/+3
When the semantics of the ->read() handlers were changed such that "buffer" is a kernel pointer, some __user annotations survived. Since they're wrong now, get rid of them. Fixes: d3ec10aa9581 ("KEYS: Don't write out to userspace while holding key semaphore") Signed-off-by: Jann Horn <jannh@google.com> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
2021-01-21security: keys: Fix fall-through warnings for ClangGustavo A. R. Silva1-0/+1
In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning by explicitly adding a break statement instead of letting the code fall through to the next case. Link: https://github.com/KSPP/linux/issues/115 Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Signed-off-by: David Howells <dhowells@redhat.com> Reviewed-by: Jarkko Sakkinen <jarkko@kernel.org> Reviewed-by: Ben Boeckel <mathstuf@gmail.com>
2021-01-16make dump_common_audit_data() safe to be called from RCU pathwalkAl Viro1-2/+3
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-01-16dump_common_audit_data(): fix racy accesses to ->d_nameAl Viro1-2/+5
We are not guaranteed the locking environment that would prevent dentry getting renamed right under us. And it's possible for old long name to be freed after rename, leading to UAF here. Cc: stable@kernel.org # v2.6.2+ Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-01-15selinux: include a consumer of the new IMA critical data hookLakshmi Ramasubramanian5-10/+127
SELinux stores the active policy in memory, so the changes to this data at runtime would have an impact on the security guarantees provided by SELinux. Measuring in-memory SELinux policy through IMA subsystem provides a secure way for the attestation service to remotely validate the policy contents at runtime. Measure the hash of the loaded policy by calling the IMA hook ima_measure_critical_data(). Since the size of the loaded policy can be large (several MB), measure the hash of the policy instead of the entire policy to avoid bloating the IMA log entry. To enable SELinux data measurement, the following steps are required: 1, Add "ima_policy=critical_data" to the kernel command line arguments to enable measuring SELinux data at boot time. For example, BOOT_IMAGE=/boot/vmlinuz-5.10.0-rc1+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset security=selinux ima_policy=critical_data 2, Add the following rule to /etc/ima/ima-policy measure func=CRITICAL_DATA label=selinux Sample measurement of the hash of SELinux policy: To verify the measured data with the current SELinux policy run the following commands and verify the output hash values match. sha256sum /sys/fs/selinux/policy | cut -d' ' -f 1 grep "selinux-policy-hash" /sys/kernel/security/integrity/ima/ascii_runtime_measurements | tail -1 | cut -d' ' -f 6 Note that the actual verification of SELinux policy would require loading the expected policy into an identical kernel on a pristine/known-safe system and run the sha256sum /sys/kernel/selinux/policy there to get the expected hash. Signed-off-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Suggested-by: Stephen Smalley <stephen.smalley.work@gmail.com> Acked-by: Paul Moore <paul@paul-moore.com> Reviewed-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2021-01-15IMA: define a builtin critical data measurement policyLakshmi Ramasubramanian1-0/+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>
2021-01-15IMA: extend critical data hook to limit the measurement based on a labelTushar Sugandhi1-3/+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>
2021-01-15IMA: limit critical data measurement based on a labelTushar Sugandhi1-3/+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>
2021-01-15IMA: add policy rule to measure critical dataTushar Sugandhi1-4/+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>
2021-01-15IMA: define a hook to measure kernel integrity critical dataTushar Sugandhi3-1/+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>
2021-01-15IMA: add support to measure buffer data hashTushar Sugandhi5-9/+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>
2021-01-15IMA: generalize keyring specific measurement constructsTushar Sugandhi4-26/+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>
2021-01-15selinux: teach SELinux about anonymous inodesDaniel Colascione2-0/+59
This change uses the anon_inodes and LSM infrastructure introduced in the previous patches to give SELinux the ability to control anonymous-inode files that are created using the new anon_inode_getfd_secure() function. A SELinux policy author detects and controls these anonymous inodes by adding a name-based type_transition rule that assigns a new security type to anonymous-inode files created in some domain. The name used for the name-based transition is the name associated with the anonymous inode for file listings --- e.g., "[userfaultfd]" or "[perf_event]". Example: type uffd_t; type_transition sysadm_t sysadm_t : anon_inode uffd_t "[userfaultfd]"; allow sysadm_t uffd_t:anon_inode { create }; (The next patch in this series is necessary for making userfaultfd support this new interface. The example above is just for exposition.) Signed-off-by: Daniel Colascione <dancol@google.com> Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-15security: add inode_init_security_anon() LSM hookLokesh Gidra1-0/+8
This change adds a new LSM hook, inode_init_security_anon(), that will be used while creating secure anonymous inodes. The hook allows/denies its creation and assigns a security context to the inode. The new hook accepts an optional context_inode parameter that callers can use to provide additional contextual information to security modules for granting/denying permission to create an anon-inode of the same type. This context_inode's security_context can also be used to initialize the newly created anon-inode's security_context. Signed-off-by: Lokesh Gidra <lokeshgidra@google.com> Reviewed-by: Eric Biggers <ebiggers@google.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-13selinux: fall back to SECURITY_FS_USE_GENFS if no xattr supportOndrej Mosnacek1-25/+52
When a superblock is assigned the SECURITY_FS_USE_XATTR behavior by the policy yet it lacks xattr support, try to fall back to genfs rather than rejecting the mount. If a genfscon rule is found for the filesystem, then change the behavior to SECURITY_FS_USE_GENFS, otherwise reject the mount as before. A similar fallback is already done in security_fs_use() if no behavior specification is found for the given filesystem. This is needed e.g. for virtiofs, which may or may not support xattrs depending on the backing host filesystem. Example: # seinfo --genfs | grep ' ramfs' genfscon ramfs / system_u:object_r:ramfs_t:s0 # echo '(fsuse xattr ramfs (system_u object_r fs_t ((s0) (s0))))' >ramfs_xattr.cil # semodule -i ramfs_xattr.cil # mount -t ramfs none /mnt Before: mount: /mnt: mount(2) system call failed: Operation not supported. After: (mount succeeds) # ls -Zd /mnt system_u:object_r:ramfs_t:s0 /mnt See also: https://lore.kernel.org/selinux/20210105142148.GA3200@redhat.com/T/ https://github.com/fedora-selinux/selinux-policy/pull/478 Cc: Vivek Goyal <vgoyal@redhat.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2021-01-13evm: Fix memleak in init_descDinghao Liu1-2/+5
tmp_tfm is allocated, but not freed on subsequent kmalloc failure, which leads to a memory leak. Free tmp_tfm. Fixes: d46eb3699502b ("evm: crypto hash replaced by shash") Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn> [zohar@linux.ibm.com: formatted/reworded patch description] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>