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2019-10-17perf_event: Add support for LSM and SELinux checksJoel Fernandes (Google)1-0/+15
In current mainline, the degree of access to perf_event_open(2) system call depends on the perf_event_paranoid sysctl. This has a number of limitations: 1. The sysctl is only a single value. Many types of accesses are controlled based on the single value thus making the control very limited and coarse grained. 2. The sysctl is global, so if the sysctl is changed, then that means all processes get access to perf_event_open(2) opening the door to security issues. This patch adds LSM and SELinux access checking which will be used in Android to access perf_event_open(2) for the purposes of attaching BPF programs to tracepoints, perf profiling and other operations from userspace. These operations are intended for production systems. 5 new LSM hooks are added: 1. perf_event_open: This controls access during the perf_event_open(2) syscall itself. The hook is called from all the places that the perf_event_paranoid sysctl is checked to keep it consistent with the systctl. The hook gets passed a 'type' argument which controls CPU, kernel and tracepoint accesses (in this context, CPU, kernel and tracepoint have the same semantics as the perf_event_paranoid sysctl). Additionally, I added an 'open' type which is similar to perf_event_paranoid sysctl == 3 patch carried in Android and several other distros but was rejected in mainline [1] in 2016. 2. perf_event_alloc: This allocates a new security object for the event which stores the current SID within the event. It will be useful when the perf event's FD is passed through IPC to another process which may try to read the FD. Appropriate security checks will limit access. 3. perf_event_free: Called when the event is closed. 4. perf_event_read: Called from the read(2) and mmap(2) syscalls for the event. 5. perf_event_write: Called from the ioctl(2) syscalls for the event. [1] https://lwn.net/Articles/696240/ Since Peter had suggest LSM hooks in 2016 [1], I am adding his Suggested-by tag below. To use this patch, we set the perf_event_paranoid sysctl to -1 and then apply selinux checking as appropriate (default deny everything, and then add policy rules to give access to domains that need it). In the future we can remove the perf_event_paranoid sysctl altogether. Suggested-by: Peter Zijlstra <peterz@infradead.org> Co-developed-by: Peter Zijlstra <peterz@infradead.org> Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Acked-by: James Morris <jmorris@namei.org> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: rostedt@goodmis.org Cc: Yonghong Song <yhs@fb.com> Cc: Kees Cook <keescook@chromium.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Alexei Starovoitov <ast@kernel.org> Cc: jeffv@google.com Cc: Jiri Olsa <jolsa@redhat.com> Cc: Daniel Borkmann <daniel@iogearbox.net> Cc: primiano@google.com Cc: Song Liu <songliubraving@fb.com> Cc: rsavitski@google.com Cc: Namhyung Kim <namhyung@kernel.org> Cc: Matthew Garrett <matthewgarrett@google.com> Link: https://lkml.kernel.org/r/20191014170308.70668-1-joel@joelfernandes.org
2019-09-28Merge branch 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-securityLinus Torvalds1-0/+13
Pull kernel lockdown mode from James Morris: "This is the latest iteration of the kernel lockdown patchset, from Matthew Garrett, David Howells and others. From the original description: This patchset introduces an optional kernel lockdown feature, intended to strengthen the boundary between UID 0 and the kernel. When enabled, various pieces of kernel functionality are restricted. Applications that rely on low-level access to either hardware or the kernel may cease working as a result - therefore this should not be enabled without appropriate evaluation beforehand. The majority of mainstream distributions have been carrying variants of this patchset for many years now, so there's value in providing a doesn't meet every distribution requirement, but gets us much closer to not requiring external patches. There are two major changes since this was last proposed for mainline: - Separating lockdown from EFI secure boot. Background discussion is covered here: https://lwn.net/Articles/751061/ - Implementation as an LSM, with a default stackable lockdown LSM module. This allows the lockdown feature to be policy-driven, rather than encoding an implicit policy within the mechanism. The new locked_down LSM hook is provided to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. The included lockdown LSM provides an implementation with a simple policy intended for general purpose use. This policy provides a coarse level of granularity, controllable via the kernel command line: lockdown={integrity|confidentiality} Enable the kernel lockdown feature. If set to integrity, kernel features that allow userland to modify the running kernel are disabled. If set to confidentiality, kernel features that allow userland to extract confidential information from the kernel are also disabled. This may also be controlled via /sys/kernel/security/lockdown and overriden by kernel configuration. New or existing LSMs may implement finer-grained controls of the lockdown features. Refer to the lockdown_reason documentation in include/linux/security.h for details. The lockdown feature has had signficant design feedback and review across many subsystems. This code has been in linux-next for some weeks, with a few fixes applied along the way. Stephen Rothwell noted that commit 9d1f8be5cf42 ("bpf: Restrict bpf when kernel lockdown is in confidentiality mode") is missing a Signed-off-by from its author. Matthew responded that he is providing this under category (c) of the DCO" * 'next-lockdown' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (31 commits) kexec: Fix file verification on S390 security: constify some arrays in lockdown LSM lockdown: Print current->comm in restriction messages efi: Restrict efivar_ssdt_load when the kernel is locked down tracefs: Restrict tracefs when the kernel is locked down debugfs: Restrict debugfs when the kernel is locked down kexec: Allow kexec_file() with appropriate IMA policy when locked down lockdown: Lock down perf when in confidentiality mode bpf: Restrict bpf when kernel lockdown is in confidentiality mode lockdown: Lock down tracing and perf kprobes when in confidentiality mode lockdown: Lock down /proc/kcore x86/mmiotrace: Lock down the testmmiotrace module lockdown: Lock down module params that specify hardware parameters (eg. ioport) lockdown: Lock down TIOCSSERIAL lockdown: Prohibit PCMCIA CIS storage when the kernel is locked down acpi: Disable ACPI table override if the kernel is locked down acpi: Ignore acpi_rsdp kernel param when the kernel has been locked down ACPI: Limit access to custom_method when the kernel is locked down x86/msr: Restrict MSR access when the kernel is locked down x86: Lock down IO port access when the kernel is locked down ...
2019-09-23Merge tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-1/+8
Pull selinux updates from Paul Moore: - Add LSM hooks, and SELinux access control hooks, for dnotify, fanotify, and inotify watches. This has been discussed with both the LSM and fs/notify folks and everybody is good with these new hooks. - The LSM stacking changes missed a few calls to current_security() in the SELinux code; we fix those and remove current_security() for good. - Improve our network object labeling cache so that we always return the object's label, even when under memory pressure. Previously we would return an error if we couldn't allocate a new cache entry, now we always return the label even if we can't create a new cache entry for it. - Convert the sidtab atomic_t counter to a normal u32 with READ/WRITE_ONCE() and memory barrier protection. - A few patches to policydb.c to clean things up (remove forward declarations, long lines, bad variable names, etc) * tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: lsm: remove current_security() selinux: fix residual uses of current_security() for the SELinux blob selinux: avoid atomic_t usage in sidtab fanotify, inotify, dnotify, security: add security hook for fs notifications selinux: always return a secid from the network caches if we find one selinux: policydb - rename type_val_to_struct_array selinux: policydb - fix some checkpatch.pl warnings selinux: shuffle around policydb.c to get rid of forward declarations
2019-08-19security: Add a "locked down" LSM hookMatthew Garrett1-0/+7
Add a mechanism to allow LSMs to make a policy decision around whether kernel functionality that would allow tampering with or examining the runtime state of the kernel should be permitted. Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <jmorris@namei.org>
2019-08-19security: Support early LSMsMatthew Garrett1-0/+6
The lockdown module is intended to allow for kernels to be locked down early in boot - sufficiently early that we don't have the ability to kmalloc() yet. Add support for early initialisation of some LSMs, and then add them to the list of names when we do full initialisation later. Early LSMs are initialised in link order and cannot be overridden via boot parameters, and cannot make use of kmalloc() (since the allocator isn't initialised yet). (Fixed by Stephen Rothwell to include a stub to fix builds when !CONFIG_SECURITY) Signed-off-by: Matthew Garrett <mjg59@google.com> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Cc: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: James Morris <jmorris@namei.org>
2019-08-12fanotify, inotify, dnotify, security: add security hook for fs notificationsAaron Goidel1-1/+8
As of now, setting watches on filesystem objects has, at most, applied a check for read access to the inode, and in the case of fanotify, requires CAP_SYS_ADMIN. No specific security hook or permission check has been provided to control the setting of watches. Using any of inotify, dnotify, or fanotify, it is possible to observe, not only write-like operations, but even read access to a file. Modeling the watch as being merely a read from the file is insufficient for the needs of SELinux. This is due to the fact that read access should not necessarily imply access to information about when another process reads from a file. Furthermore, fanotify watches grant more power to an application in the form of permission events. While notification events are solely, unidirectional (i.e. they only pass information to the receiving application), permission events are blocking. Permission events make a request to the receiving application which will then reply with a decision as to whether or not that action may be completed. This causes the issue of the watching application having the ability to exercise control over the triggering process. Without drawing a distinction within the permission check, the ability to read would imply the greater ability to control an application. Additionally, mount and superblock watches apply to all files within the same mount or superblock. Read access to one file should not necessarily imply the ability to watch all files accessed within a given mount or superblock. In order to solve these issues, a new LSM hook is implemented and has been placed within the system calls for marking filesystem objects with inotify, fanotify, and dnotify watches. These calls to the hook are placed at the point at which the target path has been resolved and are provided with the path struct, the mask of requested notification events, and the type of object on which the mark is being set (inode, superblock, or mount). The mask and obj_type have already been translated into common FS_* values shared by the entirety of the fs notification infrastructure. The path struct is passed rather than just the inode so that the mount is available, particularly for mount watches. This also allows for use of the hook by pathname-based security modules. However, since the hook is intended for use even by inode based security modules, it is not placed under the CONFIG_SECURITY_PATH conditional. Otherwise, the inode-based security modules would need to enable all of the path hooks, even though they do not use any of them. This only provides a hook at the point of setting a watch, and presumes that permission to set a particular watch implies the ability to receive all notification about that object which match the mask. This is all that is required for SELinux. If other security modules require additional hooks or infrastructure to control delivery of notification, these can be added by them. It does not make sense for us to propose hooks for which we have no implementation. The understanding that all notifications received by the requesting application are all strictly of a type for which the application has been granted permission shows that this implementation is sufficient in its coverage. Security modules wishing to provide complete control over fanotify must also implement a security_file_open hook that validates that the access requested by the watching application is authorized. Fanotify has the issue that it returns a file descriptor with the file mode specified during fanotify_init() to the watching process on event. This is already covered by the LSM security_file_open hook if the security module implements checking of the requested file mode there. Otherwise, a watching process can obtain escalated access to a file for which it has not been authorized. The selinux_path_notify hook implementation works by adding five new file permissions: watch, watch_mount, watch_sb, watch_reads, and watch_with_perm (descriptions about which will follow), and one new filesystem permission: watch (which is applied to superblock checks). The hook then decides which subset of these permissions must be held by the requesting application based on the contents of the provided mask and the obj_type. The selinux_file_open hook already checks the requested file mode and therefore ensures that a watching process cannot escalate its access through fanotify. The watch, watch_mount, and watch_sb permissions are the baseline permissions for setting a watch on an object and each are a requirement for any watch to be set on a file, mount, or superblock respectively. It should be noted that having either of the other two permissions (watch_reads and watch_with_perm) does not imply the watch, watch_mount, or watch_sb permission. Superblock watches further require the filesystem watch permission to the superblock. As there is no labeled object in view for mounts, there is no specific check for mount watches beyond watch_mount to the inode. Such a check could be added in the future, if a suitable labeled object existed representing the mount. The watch_reads permission is required to receive notifications from read-exclusive events on filesystem objects. These events include accessing a file for the purpose of reading and closing a file which has been opened read-only. This distinction has been drawn in order to provide a direct indication in the policy for this otherwise not obvious capability. Read access to a file should not necessarily imply the ability to observe read events on a file. Finally, watch_with_perm only applies to fanotify masks since it is the only way to set a mask which allows for the blocking, permission event. This permission is needed for any watch which is of this type. Though fanotify requires CAP_SYS_ADMIN, this is insufficient as it gives implicit trust to root, which we do not do, and does not support least privilege. Signed-off-by: Aaron Goidel <acgoide@tycho.nsa.gov> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Acked-by: Jan Kara <jack@suse.cz> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-06-08docs: fix broken documentation linksMauro Carvalho Chehab1-1/+1
Mostly due to x86 and acpi conversion, several documentation links are still pointing to the old file. Fix them. Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org> Reviewed-by: Wolfram Sang <wsa@the-dreams.de> Reviewed-by: Sven Van Asbroeck <TheSven73@gmail.com> Reviewed-by: Bhupesh Sharma <bhsharma@redhat.com> Acked-by: Mark Brown <broonie@kernel.org> Signed-off-by: Jonathan Corbet <corbet@lwn.net>
2019-05-07Merge branch 'work.mount-syscalls' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-0/+6
Pull mount ABI updates from Al Viro: "The syscalls themselves, finally. That's not all there is to that stuff, but switching individual filesystems to new methods is fortunately independent from everything else, so e.g. NFS series can go through NFS tree, etc. As those conversions get done, we'll be finally able to get rid of a bunch of duplication in fs/super.c introduced in the beginning of the entire thing. I expect that to be finished in the next window..." * 'work.mount-syscalls' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: vfs: Add a sample program for the new mount API vfs: syscall: Add fspick() to select a superblock for reconfiguration vfs: syscall: Add fsmount() to create a mount for a superblock vfs: syscall: Add fsconfig() for configuring and managing a context vfs: Implement logging through fs_context vfs: syscall: Add fsopen() to prepare for superblock creation Make anon_inodes unconditional teach move_mount(2) to work with OPEN_TREE_CLONE vfs: syscall: Add move_mount(2) to move mounts around vfs: syscall: Add open_tree(2) to reference or clone a mount
2019-05-07Merge tag 'selinux-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-0/+13
Pull selinux updates from Paul Moore: "We've got a few SELinux patches for the v5.2 merge window, the highlights are below: - Add LSM hooks, and the SELinux implementation, for proper labeling of kernfs. While we are only including the SELinux implementation here, the rest of the LSM folks have given the hooks a thumbs-up. - Update the SELinux mdp (Make Dummy Policy) script to actually work on a modern system. - Disallow userspace to change the LSM credentials via /proc/self/attr when the task's credentials are already overridden. The change was made in procfs because all the LSM folks agreed this was the Right Thing To Do and duplicating it across each LSM was going to be annoying" * tag 'selinux-pr-20190507' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: proc: prevent changes to overridden credentials selinux: Check address length before reading address family kernfs: fix xattr name handling in LSM helpers MAINTAINERS: update SELinux file patterns selinux: avoid uninitialized variable warning selinux: remove useless assignments LSM: lsm_hooks.h - fix missing colon in docstring selinux: Make selinux_kernfs_init_security static kernfs: initialize security of newly created nodes selinux: implement the kernfs_init_security hook LSM: add new hook for kernfs node initialization kernfs: use simple_xattrs for security attributes selinux: try security xattr after genfs for kernfs filesystems kernfs: do not alloc iattrs in kernfs_xattr_get kernfs: clean up struct kernfs_iattrs scripts/selinux: fix build selinux: use kernel linux/socket.h for genheaders and mdp scripts/selinux: modernize mdp
2019-03-26LSM: lsm_hooks.h: fix documentation formatDenis Efremov1-14/+9
Fix for name mismatch and omitted colons in the security_list_options documentation. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the shm_* hooksDenis Efremov1-18/+18
The shm_* hooks were changed in the commit "shm/security: Pass kern_ipc_perm not shmid_kernel into the shm security hooks" (7191adff2a55). The type of the argument shp was changed from shmid_kernel to kern_ipc_perm. This patch updates the documentation for the hooks accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the sem_* hooksDenis Efremov1-16/+16
The sem_* hooks were changed in the commit "sem/security: Pass kern_ipc_perm not sem_array into the sem security hooks" (aefad9593ec5). The type of the argument sma was changed from sem_array to kern_ipc_perm. This patch updates the documentation for the hooks accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the msg_queue_* hooksDenis Efremov1-19/+19
The msg_queue_* hooks were changed in the commit "msg/security: Pass kern_ipc_perm not msg_queue into the msg_queue security hooks" (d8c6e8543294). The type of the argument msq was changed from msq_queue to kern_ipc_perm. This patch updates the documentation for the hooks accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the audit_* hooksDenis Efremov1-4/+4
This patch updates the documentation for the audit_* hooks to use the same arguments names as in the hook's declarations. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the path_chmod hookDenis Efremov1-4/+5
The path_chmod hook was changed in the commit "switch security_path_chmod() to struct path *" (cdcf116d44e7). The argument @mnt was removed from the hook, @dentry was changed to @path. This patch updates the documentation accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the socket_getpeersec_dgram hookDenis Efremov1-5/+5
The socket_getpeersec_dgram hook was changed in the commit "[AF_UNIX]: Kernel memory leak fix for af_unix datagram getpeersec patch" (dc49c1f94e34). The arguments @secdata and @seclen were changed to @sock and @secid. This patch updates the documentation accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the task_setscheduler hookDenis Efremov1-3/+1
The task_setscheduler hook was changed in the commit "security: remove unused parameter from security_task_setscheduler()" (b0ae19811375). The arguments @policy, @lp were removed from the hook. This patch updates the documentation accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the socket_post_create hookDenis Efremov1-3/+3
This patch slightly fixes the documentation for the socket_post_create hook. The documentation states that i_security field is accessible through inode field of socket structure (i.e., 'sock->inode->i_security'). There is no inode field in the socket structure. The i_security field is accessible through SOCK_INODE macro. The patch updates the documentation to reflect this. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for the syslog hookDenis Efremov1-2/+1
The syslog hook was changed in the commit "capabilities/syslog: open code cap_syslog logic to fix build failure" (12b3052c3ee8). The argument @from_file was removed from the hook. This patch updates the documentation for the syslog hook accordingly. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-26LSM: fix documentation for sb_copy_data hookDenis Efremov1-1/+0
The @type argument of the sb_copy_data hook was removed in the commit "LSM/SELinux: Interfaces to allow FS to control mount options" (e0007529893c). This commit removes the description of the @type argument from the LSM documentation. Signed-off-by: Denis Efremov <efremov@ispras.ru> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-03-25LSM: lsm_hooks.h - fix missing colon in docstringOndrej Mosnacek1-1/+1
Apparently without it it is incorrect syntax and causes a warning about undocumented struct field. Fixes: b230d5aba2d1 ("LSM: add new hook for kernfs node initialization") Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20LSM: add new hook for kernfs node initializationOndrej Mosnacek1-0/+13
This patch introduces a new security hook that is intended for initializing the security data for newly created kernfs nodes, which provide a way of storing a non-default security context, but need to operate independently from mounts (and therefore may not have an associated inode at the moment of creation). The main motivation is to allow kernfs nodes to inherit the context of the parent under SELinux, similar to the behavior of security_inode_init_security(). Other LSMs may implement their own logic for handling the creation of new nodes. This patch also adds helper functions to <linux/kernfs.h> for getting/setting security xattrs of a kernfs node so that LSMs hooks are able to do their job. Other important attributes should be accessible direcly in the kernfs_node fields (in case there is need for more, then new helpers should be added to kernfs.h along with the patch that needs them). Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com> [PM: more manual merge fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-20vfs: syscall: Add move_mount(2) to move mounts aroundDavid Howells1-0/+6
Add a move_mount() system call that will move a mount from one place to another and, in the next commit, allow to attach an unattached mount tree. The new system call looks like the following: int move_mount(int from_dfd, const char *from_path, int to_dfd, const char *to_path, unsigned int flags); Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-api@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-03-12Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds1-0/+21
Pull vfs mount infrastructure updates from Al Viro: "The rest of core infrastructure; no new syscalls in that pile, but the old parts are switched to new infrastructure. At that point conversions of individual filesystems can happen independently; some are done here (afs, cgroup, procfs, etc.), there's also a large series outside of that pile dealing with NFS (quite a bit of option-parsing stuff is getting used there - it's one of the most convoluted filesystems in terms of mount-related logics), but NFS bits are the next cycle fodder. It got seriously simplified since the last cycle; documentation is probably the weakest bit at the moment - I considered dropping the commit introducing Documentation/filesystems/mount_api.txt (cutting the size increase by quarter ;-), but decided that it would be better to fix it up after -rc1 instead. That pile allows to do followup work in independent branches, which should make life much easier for the next cycle. fs/super.c size increase is unpleasant; there's a followup series that allows to shrink it considerably, but I decided to leave that until the next cycle" * 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (41 commits) afs: Use fs_context to pass parameters over automount afs: Add fs_context support vfs: Add some logging to the core users of the fs_context log vfs: Implement logging through fs_context vfs: Provide documentation for new mount API vfs: Remove kern_mount_data() hugetlbfs: Convert to fs_context cpuset: Use fs_context kernfs, sysfs, cgroup, intel_rdt: Support fs_context cgroup: store a reference to cgroup_ns into cgroup_fs_context cgroup1_get_tree(): separate "get cgroup_root to use" into a separate helper cgroup_do_mount(): massage calling conventions cgroup: stash cgroup_root reference into cgroup_fs_context cgroup2: switch to option-by-option parsing cgroup1: switch to option-by-option parsing cgroup: take options parsing into ->parse_monolithic() cgroup: fold cgroup1_mount() into cgroup1_get_tree() cgroup: start switching to fs_context ipc: Convert mqueue fs to fs_context proc: Add fs_context support to procfs ...
2019-03-07Merge tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/auditLinus Torvalds1-3/+1
Pull audit updates from Paul Moore: "A lucky 13 audit patches for v5.1. Despite the rather large diffstat, most of the changes are from two bug fix patches that move code from one Kconfig option to another. Beyond that bit of churn, the remaining changes are largely cleanups and bug-fixes as we slowly march towards container auditing. It isn't all boring though, we do have a couple of new things: file capabilities v3 support, and expanded support for filtering on filesystems to solve problems with remote filesystems. All changes pass the audit-testsuite. Please merge for v5.1" * tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: mark expected switch fall-through audit: hide auditsc_get_stamp and audit_serial prototypes audit: join tty records to their syscall audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL audit: remove unused actx param from audit_rule_match audit: ignore fcaps on umount audit: clean up AUDITSYSCALL prototypes and stubs audit: more filter PATH records keyed on filesystem magic audit: add support for fcaps v3 audit: move loginuid and sessionid from CONFIG_AUDITSYSCALL to CONFIG_AUDIT audit: add syscall information to CONFIG_CHANGE records audit: hand taken context to audit_kill_trees for syscall logging audit: give a clue what CONFIG_CHANGE op was involved
2019-02-28introduce cloning of fs_contextAl Viro1-0/+7
new primitive: vfs_dup_fs_context(). Comes with fs_context method (->dup()) for copying the filesystem-specific parts of fs_context, along with LSM one (->fs_context_dup()) for doing the same to LSM parts. [needs better commit message, and change of Author:, anyway] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-02-28vfs: Add LSM hooks for the new mount APIDavid Howells1-0/+14
Add LSM hooks for use by the new mount API and filesystem context code. This includes: (1) Hooks to handle allocation, duplication and freeing of the security record attached to a filesystem context. (2) A hook to snoop source specifications. There may be multiple of these if the filesystem supports it. They will to be local files/devices if fs_context::source_is_dev is true and will be something else, possibly remote server specifications, if false. (3) A hook to snoop superblock configuration options in key[=val] form. If the LSM decides it wants to handle it, it can suppress the option being passed to the filesystem. Note that 'val' may include commas and binary data with the fsopen patch. (4) A hook to perform validation and allocation after the configuration has been done but before the superblock is allocated and set up. (5) A hook to transfer the security from the context to a newly created superblock. (6) A hook to rule on whether a path point can be used as a mountpoint. These are intended to replace: security_sb_copy_data security_sb_kern_mount security_sb_mount security_sb_set_mnt_opts security_sb_clone_mnt_opts security_sb_parse_opts_str [AV -- some of the methods being replaced are already gone, some of the methods are not added for the lack of need] Signed-off-by: David Howells <dhowells@redhat.com> cc: linux-security-module@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2019-01-31audit: remove unused actx param from audit_rule_matchRichard Guy Briggs1-3/+1
The audit_rule_match() struct audit_context *actx parameter is not used by any in-tree consumers (selinux, apparmour, integrity, smack). The audit context is an internal audit structure that should only be accessed by audit accessor functions. It was part of commit 03d37d25e0f9 ("LSM/Audit: Introduce generic Audit LSM hooks") but appears to have never been used. Remove it. Please see the github issue https://github.com/linux-audit/audit-kernel/issues/107 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: fixed the referenced commit title] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-18LSM: Make lsm_early_cred() and lsm_early_task() local functions.Tetsuo Handa1-5/+0
Since current->cred == current->real_cred when ordered_lsm_init() is called, and lsm_early_cred()/lsm_early_task() need to be called between the amount of required bytes is determined and module specific initialization function is called, we can move these calls from individual modules to ordered_lsm_init(). Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Acked-by: Casey Schaufler <casey@schaufler-ca.com> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-10LSM: generalize flag passing to security_capableMicah Morton1-3/+5
This patch provides a general mechanism for passing flags to the security_capable LSM hook. It replaces the specific 'audit' flag that is used to tell security_capable whether it should log an audit message for the given capability check. The reason for generalizing this flag passing is so we can add an additional flag that signifies whether security_capable is being called by a setid syscall (which is needed by the proposed SafeSetID LSM). Signed-off-by: Micah Morton <mortonm@chromium.org> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: James Morris <james.morris@microsoft.com>
2019-01-08LSM: Infrastructure management of the ipc security blobCasey Schaufler1-0/+2
Move management of the kern_ipc_perm->security and msg_msg->security blobs out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Infrastructure management of the task securityCasey Schaufler1-0/+2
Move management of the task_struct->security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. The only user of this blob is AppArmor. The AppArmor use is abstracted to avoid future conflict. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Infrastructure management of the inode securityCasey Schaufler1-0/+3
Move management of the inode->i_security blob out of the individual security modules and into the security infrastructure. Instead of allocating the blobs from within the modules the modules tell the infrastructure how much space is required, and the space is allocated there. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Infrastructure management of the file securityCasey Schaufler1-0/+1
Move management of the file->f_security blob out of the individual security modules and into the infrastructure. The modules no longer allocate or free the data, instead they tell the infrastructure how much space they require. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08Infrastructure management of the cred security blobCasey Schaufler1-0/+12
Move management of the cred security blob out of the security modules and into the security infrastructre. Instead of allocating and freeing space the security modules tell the infrastructure how much space they require. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> [kees: adjusted for ordered init series] Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08capability: Initialize as LSM_ORDER_FIRSTKees Cook1-2/+0
This converts capabilities to use the new LSM_ORDER_FIRST position. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08LSM: Introduce enum lsm_orderKees Cook1-0/+6
In preparation for distinguishing the "capability" LSM from other LSMs, it must be ordered first. This introduces LSM_ORDER_MUTABLE for the general LSMs and LSM_ORDER_FIRST for capability. In the future LSM_ORDER_LAST for could be added for anything that must run last (e.g. Landlock may use this). Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08Yama: Initialize as ordered LSMKees Cook1-5/+0
This converts Yama from being a direct "minor" LSM into an ordered LSM. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08LoadPin: Initialize as ordered LSMKees Cook1-5/+0
This converts LoadPin from being a direct "minor" LSM into an ordered LSM. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08LSM: Separate idea of "major" LSM from "exclusive" LSMKees Cook1-0/+1
In order to both support old "security=" Legacy Major LSM selection, and handling real exclusivity, this creates LSM_FLAG_EXCLUSIVE and updates the selection logic to handle them. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com>
2019-01-08LSM: Tie enabling logic to presence in ordered listKees Cook1-1/+1
Until now, any LSM without an enable storage variable was considered enabled. This inverts the logic and sets defaults to true only if the LSM gets added to the ordered initialization list. (And an exception continues for the major LSMs until they are integrated into the ordered initialization in a later patch.) Signed-off-by: Kees Cook <keescook@chromium.org>
2019-01-08LSM: Lift LSM selection out of individual LSMsKees Cook1-1/+0
As a prerequisite to adjusting LSM selection logic in the future, this moves the selection logic up out of the individual major LSMs, making their init functions only run when actually enabled. This considers all LSMs enabled by default unless they specified an external "enable" variable. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
2019-01-08LSM: Plumb visibility into optional "enabled" stateKees Cook1-0/+1
In preparation for lifting the "is this LSM enabled?" logic out of the individual LSMs, pass in any special enabled state tracking (as needed for SELinux, AppArmor, and LoadPin). This should be an "int" to include handling any future cases where "enabled" is exposed via sysctl which has no "bool" type. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
2019-01-08LSM: Introduce LSM_FLAG_LEGACY_MAJORKees Cook1-0/+3
This adds a flag for the current "major" LSMs to distinguish them when we have a universal method for ordering all LSMs. It's called "legacy" since the distinction of "major" will go away in the blob-sharing world. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: John Johansen <john.johansen@canonical.com>
2018-12-21LSM: new method: ->sb_add_mnt_opt()Al Viro1-2/+3
Adding options to growing mnt_opts. NFS kludge with passing context= down into non-text-options mount switched to it, and with that the last use of ->sb_parse_opts_str() is gone. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: hide struct security_mnt_opts from any generic codeAl Viro1-5/+6
Keep void * instead, allocate on demand (in parse_str_opts, at the moment). Eventually both selinux and smack will be better off with private structures with several strings in those, rather than this "counter and two pointers to dynamically allocated arrays" ugliness. This commit allows to do that at leisure, without disrupting anything outside of given module. Changes: * instead of struct security_mnt_opt use an opaque pointer initialized to NULL. * security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and security_free_mnt_opts() take it as var argument (i.e. as void **); call sites are unchanged. * security_sb_set_mnt_opts() and security_sb_remount() take it by value (i.e. as void *). * new method: ->sb_free_mnt_opts(). Takes void *, does whatever freeing that needs to be done. * ->sb_set_mnt_opts() and ->sb_remount() might get NULL as mnt_opts argument, meaning "empty". Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: turn sb_eat_lsm_opts() into a methodAl Viro1-2/+2
Kill ->sb_copy_data() - it's used only in combination with immediately following ->sb_parse_opts_str(). Turn that combination into a new method. This is just a mechanical move - cleanups will be the next step. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()Al Viro1-2/+1
... leaving the "is it kernel-internal" logics in the caller. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: lift extracting and parsing LSM options into the caller of ->sb_remount()Al Viro1-1/+2
This paves the way for retaining the LSM options from a common filesystem mount context during a mount parameter parsing phase to be instituted prior to actual mount/reconfiguration actions. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21LSM: lift parsing LSM options into the caller of ->sb_kern_mount()Al Viro1-1/+2
This paves the way for retaining the LSM options from a common filesystem mount context during a mount parameter parsing phase to be instituted prior to actual mount/reconfiguration actions. Reviewed-by: David Howells <dhowells@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>