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2020-08-31ima: Pre-parse the list of keyrings in a KEY_CHECK ruleTyler Hicks1-45/+93
The ima_keyrings buffer was used as a work buffer for strsep()-based parsing of the "keyrings=" option of an IMA policy rule. This parsing was re-performed each time an asymmetric key was added to a kernel keyring for each loaded policy rule that contained a "keyrings=" option. An example rule specifying this option is: measure func=KEY_CHECK keyrings=a|b|c The rule says to measure asymmetric keys added to any of the kernel keyrings named "a", "b", or "c". The size of the buffer size was equal to the size of the largest "keyrings=" value seen in a previously loaded rule (5 + 1 for the NUL-terminator in the previous example) and the buffer was pre-allocated at the time of policy load. The pre-allocated buffer approach suffered from a couple bugs: 1) There was no locking around the use of the buffer so concurrent key add operations, to two different keyrings, would result in the strsep() loop of ima_match_keyring() to modify the buffer at the same time. This resulted in unexpected results from ima_match_keyring() and, therefore, could cause unintended keys to be measured or keys to not be measured when IMA policy intended for them to be measured. 2) If the kstrdup() that initialized entry->keyrings in ima_parse_rule() failed, the ima_keyrings buffer was freed and set to NULL even when a valid KEY_CHECK rule was previously loaded. The next KEY_CHECK event would trigger a call to strcpy() with a NULL destination pointer and crash the kernel. Remove the need for a pre-allocated global buffer by parsing the list of keyrings in a KEY_CHECK rule at the time of policy load. The ima_rule_entry will contain an array of string pointers which point to the name of each keyring specified in the rule. No string processing needs to happen at the time of asymmetric key add so iterating through the list and doing a string comparison is all that's required at the time of policy check. In the process of changing how the "keyrings=" policy option is handled, a couple additional bugs were fixed: 1) The rule parser accepted rules containing invalid "keyrings=" values such as "a|b||c", "a|b|", or simply "|". 2) The /sys/kernel/security/ima/policy file did not display the entire "keyrings=" value if the list of keyrings was longer than what could fit in the fixed size tbuf buffer in ima_policy_show(). Fixes: 5c7bac9fb2c5 ("IMA: pre-allocate buffer to hold keyrings string") Fixes: 2b60c0ecedf8 ("IMA: Read keyrings= option from the IMA policy") Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Reviewed-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-08-31selinux: simplify away security_policydb_len()Ondrej Mosnacek3-30/+10
Remove the security_policydb_len() calls from sel_open_policy() and instead update the inode size from the size returned from security_read_policy(). Since after this change security_policydb_len() is only called from security_load_policy(), remove it entirely and just open-code it there. Also, since security_load_policy() is always called with policy_mutex held, make it dereference the policy pointer directly and drop the unnecessary RCU locking. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-27selinux: move policy mutex to selinux_state, use in lockdep checksStephen Smalley4-43/+22
Move the mutex used to synchronize policy changes (reloads and setting of booleans) from selinux_fs_info to selinux_state and use it in lockdep checks for rcu_dereference_protected() calls in the security server functions. This makes the dependency on the mutex explicit in the code rather than relying on comments. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-26selinux: fix error handling bugs in security_load_policy()Dan Carpenter1-11/+23
There are a few bugs in the error handling for security_load_policy(). 1) If the newpolicy->sidtab allocation fails then it leads to a NULL dereference. Also the error code was not set to -ENOMEM on that path. 2) If policydb_read() failed then we call policydb_destroy() twice which meands we call kvfree(p->sym_val_to_name[i]) twice. 3) If policydb_load_isids() failed then we call sidtab_destroy() twice and that results in a double free in the sidtab_destroy_tree() function because entry.ptr_inner and entry.ptr_leaf are not set to NULL. One thing that makes this code nice to deal with is that none of the functions return partially allocated data. In other words, the policydb_read() either allocates everything successfully or it frees all the data it allocates. It never returns a mix of allocated and not allocated data. I re-wrote this to only free the successfully allocated data which avoids the double frees. I also re-ordered selinux_policy_free() so it's in the reverse order of the allocation function. Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> [PM: partially merged by hand due to merge fuzz] Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-25bpf: Implement bpf_local_storage for inodesKP Singh1-0/+6
Similar to bpf_local_storage for sockets, add local storage for inodes. The life-cycle of storage is managed with the life-cycle of the inode. i.e. the storage is destroyed along with the owning inode. The BPF LSM allocates an __rcu pointer to the bpf_local_storage in the security blob which are now stackable and can co-exist with other LSMs. Signed-off-by: KP Singh <kpsingh@google.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200825182919.1118197-6-kpsingh@chromium.org
2020-08-25selinux: convert policy read-write lock to RCUStephen Smalley4-218/+280
Convert the policy read-write lock to RCU. This is significantly simplified by the earlier work to encapsulate the policy data structures and refactor the policy load and boolean setting logic. Move the latest_granting sequence number into the selinux_policy structure so that it can be updated atomically with the policy. Since removing the policy rwlock and moving latest_granting reduces the selinux_ss structure to nothing more than a wrapper around the selinux_policy pointer, get rid of the extra layer of indirection. At present this change merely passes a hardcoded 1 to rcu_dereference_check() in the cases where we know we do not need to take rcu_read_lock(), with the preceding comment explaining why. Alternatively we could pass fsi->mutex down from selinuxfs and apply a lockdep check on it instead. Based in part on earlier attempts to convert the policy rwlock to RCU by Kaigai Kohei [1] and by Peter Enderborg [2]. [1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/ [2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/ Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Reviewed-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-24selinux: delete repeated words in commentsRandy Dunlap1-3/+3
Drop a repeated word in comments. {open, is, then} Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <stephen.smalley.work@gmail.com> Cc: Eric Paris <eparis@parisplace.org> Cc: selinux@vger.kernel.org Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: linux-security-module@vger.kernel.org [PM: fix subject line] Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva12-38/+30
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-21selinux: add basic filtering for audit trace eventsPeter Enderborg1-13/+15
This patch adds further attributes to the event. These attributes are helpful to understand the context of the message and can be used to filter the events. There are three common items. Source context, target context and tclass. There are also items from the outcome of operation performed. An event is similar to: <...>-1309 [002] .... 6346.691689: selinux_audited: requested=0x4000000 denied=0x4000000 audited=0x4000000 result=-13 scontext=system_u:system_r:cupsd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:bin_t:s0 tclass=file With systems where many denials are occurring, it is useful to apply a filter. The filtering is a set of logic that is inserted with the filter file. Example: echo "tclass==\"file\" " > events/avc/selinux_audited/filter This adds that we only get tclass=file. The trace can also have extra properties. Adding the user stack can be done with echo 1 > options/userstacktrace Now the output will be runcon-1365 [003] .... 6960.955530: selinux_audited: requested=0x4000000 denied=0x4000000 audited=0x4000000 result=-13 scontext=system_u:system_r:cupsd_t:s0-s0:c0.c1023 tcontext=system_u:object_r:bin_t:s0 tclass=file runcon-1365 [003] .... 6960.955560: <user stack trace> => <00007f325b4ce45b> => <00005607093efa57> Signed-off-by: Peter Enderborg <peter.enderborg@sony.com> Reviewed-by: Thiébaud Weksteen <tweek@google.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21selinux: add tracepoint on audited eventsThiébaud Weksteen1-0/+5
The audit data currently captures which process and which target is responsible for a denial. There is no data on where exactly in the process that call occurred. Debugging can be made easier by being able to reconstruct the unified kernel and userland stack traces [1]. Add a tracepoint on the SELinux denials which can then be used by userland (i.e. perf). Although this patch could manually be added by each OS developer to trouble shoot a denial, adding it to the kernel streamlines the developers workflow. It is possible to use perf for monitoring the event: # perf record -e avc:selinux_audited -g -a ^C # perf report -g [...] 6.40% 6.40% audited=800000 tclass=4 | __libc_start_main | |--4.60%--__GI___ioctl | entry_SYSCALL_64 | do_syscall_64 | __x64_sys_ioctl | ksys_ioctl | binder_ioctl | binder_set_nice | can_nice | capable | security_capable | cred_has_capability.isra.0 | slow_avc_audit | common_lsm_audit | avc_audit_post_callback | avc_audit_post_callback | It is also possible to use the ftrace interface: # echo 1 > /sys/kernel/debug/tracing/events/avc/selinux_audited/enable # cat /sys/kernel/debug/tracing/trace tracer: nop entries-in-buffer/entries-written: 1/1 #P:8 [...] dmesg-3624 [001] 13072.325358: selinux_denied: audited=800000 tclass=4 The tclass value can be mapped to a class by searching security/selinux/flask.h. The audited value is a bit field of the permissions described in security/selinux/av_permissions.h for the corresponding class. [1] https://source.android.com/devices/tech/debug/native_stack_dump Signed-off-by: Thiébaud Weksteen <tweek@google.com> Suggested-by: Joel Fernandes <joelaf@google.com> Reviewed-by: Peter Enderborg <peter.enderborg@sony.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21selinux: Create new booleans and class dirs out of treeDaniel Burgener1-23/+90
In order to avoid concurrency issues around selinuxfs resource availability during policy load, we first create new directories out of tree for reloaded resources, then swap them in, and finally delete the old versions. This fix focuses on concurrency in each of the two subtrees swapped, and not concurrency between the trees. This means that it is still possible that subsequent reads to eg the booleans directory and the class directory during a policy load could see the old state for one and the new for the other. The problem of ensuring that policy loads are fully atomic from the perspective of userspace is larger than what is dealt with here. This commit focuses on ensuring that the directories contents always match either the new or the old policy state from the perspective of userspace. In the previous implementation, on policy load /sys/fs/selinux is updated by deleting the previous contents of /sys/fs/selinux/{class,booleans} and then recreating them. This means that there is a period of time when the contents of these directories do not exist which can cause race conditions as userspace relies on them for information about the policy. In addition, it means that error recovery in the event of failure is challenging. In order to demonstrate the race condition that this series fixes, you can use the following commands: while true; do cat /sys/fs/selinux/class/service/perms/status >/dev/null; done & while true; do load_policy; done; In the existing code, this will display errors fairly often as the class lookup fails. (In normal operation from systemd, this would result in a permission check which would be allowed or denied based on policy settings around unknown object classes.) After applying this patch series you should expect to no longer see such error messages. Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21selinux: Standardize string literal usage for selinuxfs directory namesDaniel Burgener1-4/+6
Switch class and policy_capabilities directory names to be referred to with global constants, consistent with booleans directory name. This will allow for easy consistency of naming in future development. Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21selinux: Refactor selinuxfs directory populating functionsDaniel Burgener1-20/+25
Make sel_make_bools and sel_make_classes take the specific elements of selinux_fs_info that they need rather than the entire struct. This will allow a future patch to pass temporary elements that are not in the selinux_fs_info struct to these functions so that the original elements can be preserved until we are ready to perform the switch over. Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-21selinux: Create function for selinuxfs directory cleanupDaniel Burgener1-14/+25
Separating the cleanup from the creation will simplify two things in future patches in this series. First, the creation can be made generic, to create directories not tied to the selinux_fs_info structure. Second, we will ultimately want to reorder creation and deletion so that the deletions aren't performed until the new directory structures have already been moved into place. Signed-off-by: Daniel Burgener <dburgener@linux.microsoft.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-20selinux: permit removing security.selinux xattr before policy loadStephen Smalley1-0/+3
Currently SELinux denies attempts to remove the security.selinux xattr always, even when permissive or no policy is loaded. This was originally motivated by the view that all files should be labeled, even if that label is unlabeled_t, and we shouldn't permit files that were once labeled to have their labels removed entirely. This however prevents removing SELinux xattrs in the case where one "disables" SELinux by not loading a policy (e.g. a system where runtime disable is removed and selinux=0 was not specified). Allow removing the xattr before SELinux is initialized. We could conceivably permit it even after initialization if permissive, or introduce a separate permission check here. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-20device_cgroup: Fix RCU list debugging warningAmol Grover1-1/+2
exceptions may be traversed using list_for_each_entry_rcu() outside of an RCU read side critical section BUT under the protection of decgroup_mutex. Hence add the corresponding lockdep expression to fix the following false-positive warning: [ 2.304417] ============================= [ 2.304418] WARNING: suspicious RCU usage [ 2.304420] 5.5.4-stable #17 Tainted: G E [ 2.304422] ----------------------------- [ 2.304424] security/device_cgroup.c:355 RCU-list traversed in non-reader section!! Signed-off-by: Amol Grover <frextrite@gmail.com> Signed-off-by: James Morris <jmorris@namei.org>
2020-08-20selinux: fix memdup.cocci warningskernel test robot1-3/+2
Use kmemdup rather than duplicating its implementation Generated by: scripts/coccinelle/api/memdup.cocci Fixes: c7c556f1e81b ("selinux: refactor changing booleans") CC: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: kernel test robot <lkp@intel.com> Signed-off-by: Julia Lawall <julia.lawall@inria.fr> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-19selinux: avoid dereferencing the policy prior to initializationStephen Smalley1-0/+60
Certain SELinux security server functions (e.g. security_port_sid, called during bind) were not explicitly testing to see if SELinux has been initialized (i.e. initial policy loaded) and handling the no-policy-loaded case. In the past this happened to work because the policydb was statically allocated and could always be accessed, but with the recent encapsulation of policy state and conversion to dynamic allocation, we can no longer access the policy state prior to initialization. Add a test of !selinux_initialized(state) to all of the exported functions that were missing them and handle appropriately. Fixes: 461698026ffa ("selinux: encapsulate policy state, refactor policy load") Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org> Tested-by: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-19selinux: fix allocation failure check on newpolicy->sidtabColin Ian King1-1/+1
The allocation check of newpolicy->sidtab is null checking if newpolicy is null and not newpolicy->sidtab. Fix this. Addresses-Coverity: ("Logically dead code") Fixes: c7c556f1e81b ("selinux: refactor changing booleans") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17selinux: refactor changing booleansStephen Smalley8-64/+368
Refactor the logic for changing SELinux policy booleans in a similar manner to the refactoring of policy load, thereby reducing the size of the critical section when the policy write-lock is held and making it easier to convert the policy rwlock to RCU in the future. Instead of directly modifying the policydb in place, modify a copy and then swap it into place through a single pointer update. Only fully copy the portions of the policydb that are affected by boolean changes to avoid the full cost of a deep policydb copy. Introduce another level of indirection for the sidtab since changing booleans does not require updating the sidtab, unlike policy load. While we are here, create a common helper for notifying other kernel components and userspace of a policy change and call it from both security_set_bools() and selinux_policy_commit(). Based on an old (2004) patch by Kaigai Kohei [1] to convert the policy rwlock to RCU that was deferred at the time since it did not significantly improve performance and introduced complexity. Peter Enderborg later submitted a patch series to convert to RCU [2] that would have made changing booleans a much more expensive operation by requiring a full policydb_write();policydb_read(); sequence to deep copy the entire policydb and also had concerns regarding atomic allocations. This change is now simplified by the earlier work to encapsulate policy state in the selinux_policy struct and to refactor policy load. After this change, the last major obstacle to converting the policy rwlock to RCU is likely the sidtab live convert support. [1] https://lore.kernel.org/selinux/6e2f9128-e191-ebb3-0e87-74bfccb0767f@tycho.nsa.gov/ [2] https://lore.kernel.org/selinux/20180530141104.28569-1-peter.enderborg@sony.com/ Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17selinux: move policy commit after updating selinuxfsStephen Smalley6-80/+104
With the refactoring of the policy load logic in the security server from the previous change, it is now possible to split out the committing of the new policy from security_load_policy() and perform it only after successful updating of selinuxfs. Change security_load_policy() to return the newly populated policy data structures to the caller, export selinux_policy_commit() for external callers, and introduce selinux_policy_cancel() to provide a way to cancel the policy load in the event of an error during updating of the selinuxfs directory tree. Further, rework the interfaces used by selinuxfs to get information from the policy when creating the new directory tree to take and act upon the new policy data structure rather than the current/active policy. Update selinuxfs to use these updated and new interfaces. While we are here, stop re-creating the policy_capabilities directory on each policy load since it does not depend on the policy, and stop trying to create the booleans and classes directories during the initial creation of selinuxfs since no information is available until first policy load. After this change, a failure while updating the booleans and class directories will cause the entire policy load to be canceled, leaving the original policy intact, and policy load notifications to userspace will only happen after a successful completion of updating those directories. This does not (yet) provide full atomicity with respect to the updating of the directory trees themselves. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17selinux: encapsulate policy state, refactor policy loadStephen Smalley2-192/+221
Encapsulate the policy state in its own structure (struct selinux_policy) that is separately allocated but referenced from the selinux_ss structure. The policy state includes the SID table (particularly the context structures), the policy database, and the mapping between the kernel classes/permissions and the policy values. Refactor the security server portion of the policy load logic to cleanly separate loading of the new structures from committing the new policy. Unify the initial policy load and reload code paths as much as possible, avoiding duplicated code. Make sure we are taking the policy read-lock prior to any dereferencing of the policy. Move the copying of the policy capability booleans into the state structure outside of the policy write-lock because they are separate from the policy and are read outside of any policy lock; possibly they should be using at least READ_ONCE/WRITE_ONCE or smp_load_acquire/store_release. These changes simplify the policy loading logic, reduce the size of the critical section while holding the policy write-lock, and should facilitate future changes to e.g. refactor the entire policy reload logic including the selinuxfs code to make the updating of the policy and the selinuxfs directory tree atomic and/or to convert the policy read-write lock to RCU. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-17scripts/selinux,selinux: update mdp to enable policy capabilitiesStephen Smalley4-26/+40
Presently mdp does not enable any SELinux policy capabilities in the dummy policy it generates. Thus, policies derived from it will by default lack various features commonly used in modern policies such as open permission, extended socket classes, network peer controls, etc. Split the policy capability definitions out into their own headers so that we can include them into mdp without pulling in other kernel headers and extend mdp generate policycap statements for the policy capabilities known to the kernel. Policy authors may wish to selectively remove some of these from the generated policy. Signed-off-by: Stephen Smalley <stephen.smalley.work@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-08-12Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-1/+1
Merge more updates from Andrew Morton: - most of the rest of MM (memcg, hugetlb, vmscan, proc, compaction, mempolicy, oom-kill, hugetlbfs, migration, thp, cma, util, memory-hotplug, cleanups, uaccess, migration, gup, pagemap), - various other subsystems (alpha, misc, sparse, bitmap, lib, bitops, checkpatch, autofs, minix, nilfs, ufs, fat, signals, kmod, coredump, exec, kdump, rapidio, panic, kcov, kgdb, ipc). * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (164 commits) mm/gup: remove task_struct pointer for all gup code mm: clean up the last pieces of page fault accountings mm/xtensa: use general page fault accounting mm/x86: use general page fault accounting mm/sparc64: use general page fault accounting mm/sparc32: use general page fault accounting mm/sh: use general page fault accounting mm/s390: use general page fault accounting mm/riscv: use general page fault accounting mm/powerpc: use general page fault accounting mm/parisc: use general page fault accounting mm/openrisc: use general page fault accounting mm/nios2: use general page fault accounting mm/nds32: use general page fault accounting mm/mips: use general page fault accounting mm/microblaze: use general page fault accounting mm/m68k: use general page fault accounting mm/ia64: use general page fault accounting mm/hexagon: use general page fault accounting mm/csky: use general page fault accounting ...
2020-08-12mm/gup: remove task_struct pointer for all gup codePeter Xu1-1/+1
After the cleanup of page fault accounting, gup does not need to pass task_struct around any more. Remove that parameter in the whole gup stack. Signed-off-by: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: John Hubbard <jhubbard@nvidia.com> Link: http://lkml.kernel.org/r/20200707225021.200906-26-peterx@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-11Merge tag 'for-v5.9' of ↵Linus Torvalds10-10/+10
git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security Pull security subsystem updates from James Morris: "A couple of minor documentation updates only for this release" * tag 'for-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: LSM: drop duplicated words in header file comments Replace HTTP links with HTTPS ones: security
2020-08-07mm, treewide: rename kzfree() to kfree_sensitive()Waiman Long10-62/+62
As said by Linus: A symmetric naming is only helpful if it implies symmetries in use. Otherwise it's actively misleading. In "kzalloc()", the z is meaningful and an important part of what the caller wants. In "kzfree()", the z is actively detrimental, because maybe in the future we really _might_ want to use that "memfill(0xdeadbeef)" or something. The "zero" part of the interface isn't even _relevant_. The main reason that kzfree() exists is to clear sensitive information that should not be leaked to other future users of the same memory objects. Rename kzfree() to kfree_sensitive() to follow the example of the recently added kvfree_sensitive() and make the intention of the API more explicit. In addition, memzero_explicit() is used to clear the memory to make sure that it won't get optimized away by the compiler. The renaming is done by using the command sequence: git grep -w --name-only kzfree |\ xargs sed -i 's/kzfree/kfree_sensitive/' followed by some editing of the kfree_sensitive() kerneldoc and adding a kzfree backward compatibility macro in slab.h. [akpm@linux-foundation.org: fs/crypto/inline_crypt.c needs linux/slab.h] [akpm@linux-foundation.org: fix fs/crypto/inline_crypt.c some more] Suggested-by: Joe Perches <joe@perches.com> Signed-off-by: Waiman Long <longman@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com> Cc: James Morris <jmorris@namei.org> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Joe Perches <joe@perches.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: David Rientjes <rientjes@google.com> Cc: Dan Carpenter <dan.carpenter@oracle.com> Cc: "Jason A . Donenfeld" <Jason@zx2c4.com> Link: http://lkml.kernel.org/r/20200616154311.12314-3-longman@redhat.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-08-06Replace HTTP links with HTTPS ones: securityAlexander A. Klimov10-10/+10
Rationale: Reduces attack surface on kernel devs opening the links for MITM as HTTPS traffic is much harder to manipulate. Deterministic algorithm: For each file: If not .svg: For each line: If doesn't contain `\bxmlns\b`: For each link, `\bhttp://[^# \t\r\n]*(?:\w|/)`: If both the HTTP and HTTPS versions return 200 OK and serve the same content: Replace HTTP with HTTPS. Signed-off-by: Alexander A. Klimov <grandmaster@al2klimov.de> Acked-by: John Johansen <john.johansen@canonical.com> Signed-off-by: James Morris <jmorris@namei.org>
2020-08-06Merge tag 'integrity-v5.9' of ↵Linus Torvalds12-140/+283
git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity Pull integrity updates from Mimi Zohar: "The nicest change is the IMA policy rule checking. The other changes include allowing the kexec boot cmdline line measure policy rules to be defined in terms of the inode associated with the kexec kernel image, making the IMA_APPRAISE_BOOTPARAM, which governs the IMA appraise mode (log, fix, enforce), a runtime decision based on the secure boot mode of the system, and including errno in the audit log" * tag 'integrity-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/zohar/linux-integrity: integrity: remove redundant initialization of variable ret ima: move APPRAISE_BOOTPARAM dependency on ARCH_POLICY to runtime ima: AppArmor satisfies the audit rule requirements ima: Rename internal filter rule functions ima: Support additional conditionals in the KEXEC_CMDLINE hook function ima: Use the common function to detect LSM conditionals in a rule ima: Move comprehensive rule validation checks out of the token parser ima: Use correct type for the args_p member of ima_rule_entry.lsm elements ima: Shallow copy the args_p member of ima_rule_entry.lsm elements ima: Fail rule parsing when appraise_flag=blacklist is unsupportable ima: Fail rule parsing when the KEY_CHECK hook is combined with an invalid cond ima: Fail rule parsing when the KEXEC_CMDLINE hook is combined with an invalid cond ima: Fail rule parsing when buffer hook functions have an invalid action ima: Free the entire rule if it fails to parse ima: Free the entire rule when deleting a list of rules ima: Have the LSM free its audit rule IMA: Add audit log for failure conditions integrity: Add errno field in audit message
2020-08-06Merge tag 'Smack-for-5.9' of git://github.com/cschaufler/smack-nextLinus Torvalds1-3/+16
Pull smack updates from Casey Schaufler: "Minor fixes to Smack for the v5.9 release. All were found by automated checkers and have straightforward resolution" * tag 'Smack-for-5.9' of git://github.com/cschaufler/smack-next: Smack: prevent underflow in smk_set_cipso() Smack: fix another vsscanf out of bounds Smack: fix use-after-free in smk_write_relabel_self()
2020-08-04Merge tag 'cap-checkpoint-restore-v5.9' of ↵Linus Torvalds1-2/+3
git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux Pull checkpoint-restore updates from Christian Brauner: "This enables unprivileged checkpoint/restore of processes. Given that this work has been going on for quite some time the first sentence in this summary is hopefully more exciting than the actual final code changes required. Unprivileged checkpoint/restore has seen a frequent increase in interest over the last two years and has thus been one of the main topics for the combined containers & checkpoint/restore microconference since at least 2018 (cf. [1]). Here are just the three most frequent use-cases that were brought forward: - The JVM developers are integrating checkpoint/restore into a Java VM to significantly decrease the startup time. - In high-performance computing environment a resource manager will typically be distributing jobs where users are always running as non-root. Long-running and "large" processes with significant startup times are supposed to be checkpointed and restored with CRIU. - Container migration as a non-root user. In all of these scenarios it is either desirable or required to run without CAP_SYS_ADMIN. The userspace implementation of checkpoint/restore CRIU already has the pull request for supporting unprivileged checkpoint/restore up (cf. [2]). To enable unprivileged checkpoint/restore a new dedicated capability CAP_CHECKPOINT_RESTORE is introduced. This solution has last been discussed in 2019 in a talk by Google at Linux Plumbers (cf. [1] "Update on Task Migration at Google Using CRIU") with Adrian and Nicolas providing the implementation now over the last months. In essence, this allows the CRIU binary to be installed with the CAP_CHECKPOINT_RESTORE vfs capability set thereby enabling unprivileged users to restore processes. To make this possible the following permissions are altered: - Selecting a specific PID via clone3() set_tid relaxed from userns CAP_SYS_ADMIN to CAP_CHECKPOINT_RESTORE. - Selecting a specific PID via /proc/sys/kernel/ns_last_pid relaxed from userns CAP_SYS_ADMIN to CAP_CHECKPOINT_RESTORE. - Accessing /proc/pid/map_files relaxed from init userns CAP_SYS_ADMIN to init userns CAP_CHECKPOINT_RESTORE. - Changing /proc/self/exe from userns CAP_SYS_ADMIN to userns CAP_CHECKPOINT_RESTORE. Of these four changes the /proc/self/exe change deserves a few words because the reasoning behind even restricting /proc/self/exe changes in the first place is just full of historical quirks and tracking this down was a questionable version of fun that I'd like to spare others. In short, it is trivial to change /proc/self/exe as an unprivileged user, i.e. without userns CAP_SYS_ADMIN right now. Either via ptrace() or by simply intercepting the elf loader in userspace during exec. Nicolas was nice enough to even provide a POC for the latter (cf. [3]) to illustrate this fact. The original patchset which introduced PR_SET_MM_MAP had no permissions around changing the exe link. They too argued that it is trivial to spoof the exe link already which is true. The argument brought up against this was that the Tomoyo LSM uses the exe link in tomoyo_manager() to detect whether the calling process is a policy manager. This caused changing the exe links to be guarded by userns CAP_SYS_ADMIN. All in all this rather seems like a "better guard it with something rather than nothing" argument which imho doesn't qualify as a great security policy. Again, because spoofing the exe link is possible for the calling process so even if this were security relevant it was broken back then and would be broken today. So technically, dropping all permissions around changing the exe link would probably be possible and would send a clearer message to any userspace that relies on /proc/self/exe for security reasons that they should stop doing this but for now we're only relaxing the exe link permissions from userns CAP_SYS_ADMIN to userns CAP_CHECKPOINT_RESTORE. There's a final uapi change in here. Changing the exe link used to accidently return EINVAL when the caller lacked the necessary permissions instead of the more correct EPERM. This pr contains a commit fixing this. I assume that userspace won't notice or care and if they do I will revert this commit. But since we are changing the permissions anyway it seems like a good opportunity to try this fix. With these changes merged unprivileged checkpoint/restore will be possible and has already been tested by various users" [1] LPC 2018 1. "Task Migration at Google Using CRIU" https://www.youtube.com/watch?v=yI_1cuhoDgA&t=12095 2. "Securely Migrating Untrusted Workloads with CRIU" https://www.youtube.com/watch?v=yI_1cuhoDgA&t=14400 LPC 2019 1. "CRIU and the PID dance" https://www.youtube.com/watch?v=LN2CUgp8deo&list=PLVsQ_xZBEyN30ZA3Pc9MZMFzdjwyz26dO&index=9&t=2m48s 2. "Update on Task Migration at Google Using CRIU" https://www.youtube.com/watch?v=LN2CUgp8deo&list=PLVsQ_xZBEyN30ZA3Pc9MZMFzdjwyz26dO&index=9&t=1h2m8s [2] https://github.com/checkpoint-restore/criu/pull/1155 [3] https://github.com/nviennot/run_as_exe * tag 'cap-checkpoint-restore-v5.9' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux: selftests: add clone3() CAP_CHECKPOINT_RESTORE test prctl: exe link permission error changed from -EINVAL to -EPERM prctl: Allow local CAP_CHECKPOINT_RESTORE to change /proc/self/exe proc: allow access in init userns for map_files with CAP_CHECKPOINT_RESTORE pid_namespace: use checkpoint_restore_ns_capable() for ns_last_pid pid: use checkpoint_restore_ns_capable() for set_tid capabilities: Introduce CAP_CHECKPOINT_RESTORE
2020-08-04Merge branch 'exec-linus' of ↵Linus Torvalds3-5/+5
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull execve updates from Eric Biederman: "During the development of v5.7 I ran into bugs and quality of implementation issues related to exec that could not be easily fixed because of the way exec is implemented. So I have been diggin into exec and cleaning up what I can. This cycle I have been looking at different ideas and different implementations to see what is possible to improve exec, and cleaning the way exec interfaces with in kernel users. Only cleaning up the interfaces of exec with rest of the kernel has managed to stabalize and make it through review in time for v5.9-rc1 resulting in 2 sets of changes this cycle. - Implement kernel_execve - Make the user mode driver code a better citizen With kernel_execve the code size got a little larger as the copying of parameters from userspace and copying of parameters from userspace is now separate. The good news is kernel threads no longer need to play games with set_fs to use exec. Which when combined with the rest of Christophs set_fs changes should security bugs with set_fs much more difficult" * 'exec-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: (23 commits) exec: Implement kernel_execve exec: Factor bprm_stack_limits out of prepare_arg_pages exec: Factor bprm_execve out of do_execve_common exec: Move bprm_mm_init into alloc_bprm exec: Move initialization of bprm->filename into alloc_bprm exec: Factor out alloc_bprm exec: Remove unnecessary spaces from binfmts.h umd: Stop using split_argv umd: Remove exit_umh bpfilter: Take advantage of the facilities of struct pid exit: Factor thread_group_exited out of pidfd_poll umd: Track user space drivers with struct pid bpfilter: Move bpfilter_umh back into init data exec: Remove do_execve_file umh: Stop calling do_execve_file umd: Transform fork_usermode_blob into fork_usermode_driver umd: Rename umd_info.cmdline umd_info.driver_name umd: For clarity rename umh_info umd_info umh: Separate the user mode driver and the user mode helper support umh: Remove call_usermodehelper_setup_file. ...
2020-08-04Merge tag 'audit-pr-20200803' of ↵Linus Torvalds5-55/+49
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit Pull audit updates from Paul Moore: "Aside from some smaller bug fixes, here are the highlights: - add a new backlog wait metric to the audit status message, this is intended to help admins determine how long processes have been waiting for the audit backlog queue to clear - generate audit records for nftables configuration changes - generate CWD audit records for for the relevant LSM audit records" * tag 'audit-pr-20200803' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: report audit wait metric in audit status reply audit: purge audit_log_string from the intra-kernel audit API audit: issue CWD record to accompany LSM_AUDIT_DATA_* records audit: use the proper gfp flags in the audit_log_nfcfg() calls audit: remove unused !CONFIG_AUDITSYSCALL __audit_inode* stubs audit: add gfp parameter to audit_log_nfcfg audit: log nftables configuration change events audit: Use struct_size() helper in alloc_chunk
2020-08-04Merge tag 'selinux-pr-20200803' of ↵Linus Torvalds14-161/+240
git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux Pull selinux updates from Paul Moore: "Beyond the usual smattering of bug fixes, we've got three small improvements worth highlighting: - improved SELinux policy symbol table performance due to a reworking of the insert and search functions - allow reading of SELinux labels before the policy is loaded, allowing for some more "exotic" initramfs approaches - improved checking an error reporting about process class/permissions during SELinux policy load" * tag 'selinux-pr-20200803' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: complete the inlining of hashtab functions selinux: prepare for inlining of hashtab functions selinux: specialize symtab insert and search functions selinux: Fix spelling mistakes in the comments selinux: fixed a checkpatch warning with the sizeof macro selinux: log error messages on required process class / permissions scripts/selinux/mdp: fix initial SID handling selinux: allow reading labels before policy is loaded
2020-08-04Merge tag 'var-init-v5.9-rc1' of ↵Linus Torvalds1-4/+25
git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux Pull automatic variable initialization updates from Kees Cook: "This adds the "zero" init option from Clang, which is being used widely in production builds of Android and Chrome OS (though it also keeps the "pattern" init, which is better for debug builds). - Introduce CONFIG_INIT_STACK_ALL_ZERO (Alexander Potapenko)" * tag 'var-init-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux: security: allow using Clang's zero initialization for stack variables
2020-08-03Merge tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-blockLinus Torvalds1-0/+1
Pull core block updates from Jens Axboe: "Good amount of cleanups and tech debt removals in here, and as a result, the diffstat shows a nice net reduction in code. - Softirq completion cleanups (Christoph) - Stop using ->queuedata (Christoph) - Cleanup bd claiming (Christoph) - Use check_events, moving away from the legacy media change (Christoph) - Use inode i_blkbits consistently (Christoph) - Remove old unused writeback congestion bits (Christoph) - Cleanup/unify submission path (Christoph) - Use bio_uninit consistently, instead of bio_disassociate_blkg (Christoph) - sbitmap cleared bits handling (John) - Request merging blktrace event addition (Jan) - sysfs add/remove race fixes (Luis) - blk-mq tag fixes/optimizations (Ming) - Duplicate words in comments (Randy) - Flush deferral cleanup (Yufen) - IO context locking/retry fixes (John) - struct_size() usage (Gustavo) - blk-iocost fixes (Chengming) - blk-cgroup IO stats fixes (Boris) - Various little fixes" * tag 'for-5.9/block-20200802' of git://git.kernel.dk/linux-block: (135 commits) block: blk-timeout: delete duplicated word block: blk-mq-sched: delete duplicated word block: blk-mq: delete duplicated word block: genhd: delete duplicated words block: elevator: delete duplicated word and fix typos block: bio: delete duplicated words block: bfq-iosched: fix duplicated word iocost_monitor: start from the oldest usage index iocost: Fix check condition of iocg abs_vdebt block: Remove callback typedefs for blk_mq_ops block: Use non _rcu version of list functions for tag_set_list blk-cgroup: show global disk stats in root cgroup io.stat blk-cgroup: make iostat functions visible to stat printing block: improve discard bio alignment in __blkdev_issue_discard() block: change REQ_OP_ZONE_RESET and REQ_OP_ZONE_RESET_ALL to be odd numbers block: defer flush request no matter whether we have elevator block: make blk_timeout_init() static block: remove retry loop in ioc_release_fn() block: remove unnecessary ioc nested locking block: integrate bd_start_claiming into __blkdev_get ...
2020-07-27integrity: remove redundant initialization of variable retColin Ian King1-1/+1
The variable ret is being initialized with a value that is never read and it is being updated later with a new value. The initialization is redundant and can be removed. Fixes: eb5798f2e28f ("integrity: convert digsig to akcipher api") Signed-off-by: Colin Ian King <colin.king@canonical.com> Acked-by: James Morris <jamorris@linux.microsoft.com> Addresses-Coverity: ("Unused value") Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-27Smack: prevent underflow in smk_set_cipso()Dan Carpenter1-1/+1
We have an upper bound on "maplevel" but forgot to check for negative values. Fixes: e114e473771c ("Smack: Simplified Mandatory Access Control Kernel") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-07-27Smack: fix another vsscanf out of boundsDan Carpenter1-0/+4
This is similar to commit 84e99e58e8d1 ("Smack: slab-out-of-bounds in vsscanf") where we added a bounds check on "rule". Reported-by: syzbot+a22c6092d003d6fe1122@syzkaller.appspotmail.com Fixes: f7112e6c9abf ("Smack: allow for significantly longer Smack labels v4") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2020-07-21audit: purge audit_log_string from the intra-kernel audit APIRichard Guy Briggs5-55/+44
audit_log_string() was inteded to be an internal audit function and since there are only two internal uses, remove them. Purge all external uses of it by restructuring code to use an existing audit_log_format() or using audit_log_format(). Please see the upstream issue https://github.com/linux-audit/audit-kernel/issues/84 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-07-21exec: Implement kernel_execveEric W. Biederman3-5/+5
To allow the kernel not to play games with set_fs to call exec implement kernel_execve. The function kernel_execve takes pointers into kernel memory and copies the values pointed to onto the new userspace stack. The calls with arguments from kernel space of do_execve are replaced with calls to kernel_execve. The calls do_execve and do_execveat are made static as there are now no callers outside of exec. The comments that mention do_execve are updated to refer to kernel_execve or execve depending on the circumstances. In addition to correcting the comments, this makes it easy to grep for do_execve and verify it is not used. Inspired-by: https://lkml.kernel.org/r/20200627072704.2447163-1-hch@lst.de Reviewed-by: Kees Cook <keescook@chromium.org> Link: https://lkml.kernel.org/r/87wo365ikj.fsf@x220.int.ebiederm.org Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-07-20ima: move APPRAISE_BOOTPARAM dependency on ARCH_POLICY to runtimeBruno Meneguele2-1/+7
The IMA_APPRAISE_BOOTPARAM config allows enabling different "ima_appraise=" modes - log, fix, enforce - at run time, but not when IMA architecture specific policies are enabled.  This prevents properly labeling the filesystem on systems where secure boot is supported, but not enabled on the platform.  Only when secure boot is actually enabled should these IMA appraise modes be disabled. This patch removes the compile time dependency and makes it a runtime decision, based on the secure boot state of that platform. Test results as follows: -> x86-64 with secure boot enabled [ 0.015637] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix [ 0.015668] ima: Secure boot enabled: ignoring ima_appraise=fix boot parameter option -> powerpc with secure boot disabled [ 0.000000] Kernel command line: <...> ima_policy=appraise_tcb ima_appraise=fix [ 0.000000] Secure boot mode disabled -> Running the system without secure boot and with both options set: CONFIG_IMA_APPRAISE_BOOTPARAM=y CONFIG_IMA_ARCH_POLICY=y Audit prompts "missing-hash" but still allow execution and, consequently, filesystem labeling: type=INTEGRITY_DATA msg=audit(07/09/2020 12:30:27.778:1691) : pid=4976 uid=root auid=root ses=2 subj=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023 op=appraise_data cause=missing-hash comm=bash name=/usr/bin/evmctl dev="dm-0" ino=493150 res=no Cc: stable@vger.kernel.org Fixes: d958083a8f64 ("x86/ima: define arch_get_ima_policy() for x86") Signed-off-by: Bruno Meneguele <bmeneg@redhat.com> Cc: stable@vger.kernel.org # 5.0 Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: AppArmor satisfies the audit rule requirementsTyler Hicks1-1/+1
AppArmor meets all the requirements for IMA in terms of audit rules since commit e79c26d04043 ("apparmor: Add support for audit rule filtering"). Update IMA's Kconfig section for CONFIG_IMA_LSM_RULES to reflect this. Fixes: e79c26d04043 ("apparmor: Add support for audit rule filtering") Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Rename internal filter rule functionsTyler Hicks2-25/+21
Rename IMA's internal filter rule functions from security_filter_rule_*() to ima_filter_rule_*(). This avoids polluting the security_* namespace, which is typically reserved for general security subsystem infrastructure. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Suggested-by: Casey Schaufler <casey@schaufler-ca.com> [zohar@linux.ibm.com: reword using the term "filter", not "audit"] Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Support additional conditionals in the KEXEC_CMDLINE hook functionTyler Hicks7-22/+28
Take the properties of the kexec kernel's inode and the current task ownership into consideration when matching a KEXEC_CMDLINE operation to the rules in the IMA policy. This allows for some uniformity when writing IMA policy rules for KEXEC_KERNEL_CHECK, KEXEC_INITRAMFS_CHECK, and KEXEC_CMDLINE operations. Prior to this patch, it was not possible to write a set of rules like this: dont_measure func=KEXEC_KERNEL_CHECK obj_type=foo_t dont_measure func=KEXEC_INITRAMFS_CHECK obj_type=foo_t dont_measure func=KEXEC_CMDLINE obj_type=foo_t measure func=KEXEC_KERNEL_CHECK measure func=KEXEC_INITRAMFS_CHECK measure func=KEXEC_CMDLINE The inode information associated with the kernel being loaded by a kexec_kernel_load(2) syscall can now be included in the decision to measure or not Additonally, the uid, euid, and subj_* conditionals can also now be used in KEXEC_CMDLINE rules. There was no technical reason as to why those conditionals weren't being considered previously other than ima_match_rules() didn't have a valid inode to use so it immediately bailed out for KEXEC_CMDLINE operations rather than going through the full list of conditional comparisons. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Cc: Eric Biederman <ebiederm@xmission.com> Cc: kexec@lists.infradead.org Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Use the common function to detect LSM conditionals in a ruleTyler Hicks1-9/+2
Make broader use of ima_rule_contains_lsm_cond() to check if a given rule contains an LSM conditional. This is a code cleanup and has no user-facing change. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reviewed-by: Mimi Zohar <zohar@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Move comprehensive rule validation checks out of the token parserTyler Hicks3-46/+37
Use ima_validate_rule(), at the end of the token parsing stage, to verify combinations of actions, hooks, and flags. This is useful to increase readability by consolidating such checks into a single function and also because rule conditionals can be specified in arbitrary order making it difficult to do comprehensive rule validation until the entire rule has been parsed. This allows for the check that ties together the "keyrings" conditional with the KEY_CHECK function hook to be moved into the final rule validation. The modsig check no longer needs to compiled conditionally because the token parser will ensure that modsig support is enabled before accepting "imasig|modsig" appraise type values. The final rule validation will ensure that appraise_type and appraise_flag options are only present in appraise rules. Finally, this allows for the check that ties together the "pcr" conditional with the measure action to be moved into the final rule validation. Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Use correct type for the args_p member of ima_rule_entry.lsm elementsTyler Hicks1-9/+9
Make args_p be of the char pointer type rather than have it be a void pointer that gets casted to char pointer when it is used. It is a simple NUL-terminated string as returned by match_strdup(). Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Shallow copy the args_p member of ima_rule_entry.lsm elementsTyler Hicks1-10/+8
The args_p member is a simple string that is allocated by ima_rule_init(). Shallow copy it like other non-LSM references in ima_rule_entry structs. There are no longer any necessary error path cleanups to do in ima_lsm_copy_rule(). Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>
2020-07-20ima: Fail rule parsing when appraise_flag=blacklist is unsupportableTyler Hicks1-1/+14
Verifying that a file hash is not blacklisted is currently only supported for files with appended signatures (modsig). In the future, this might change. For now, the "appraise_flag" option is only appropriate for appraise actions and its "blacklist" value is only appropriate when CONFIG_IMA_APPRAISE_MODSIG is enabled and "appraise_flag=blacklist" is only appropriate when "appraise_type=imasig|modsig" is also present. Make this clear at policy load so that IMA policy authors don't assume that other uses of "appraise_flag=blacklist" are supported. Fixes: 273df864cf74 ("ima: Check against blacklisted hashes for files with modsig") Signed-off-by: Tyler Hicks <tyhicks@linux.microsoft.com> Reivewed-by: Nayna Jain <nayna@linux.ibm.com> Tested-by: Nayna Jain <nayna@linux.ibm.com> Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>