path: root/security/selinux/selinuxfs.c
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2022-08-30selinux: use int arrays for boolean valuesChristian Göttsche
Do not cast pointers of signed integers to pointers of unsigned integers and vice versa. It should currently not be an issue since they hold SELinux boolean values which should only contain either 0's or 1's, which should have the same representation. Reported by sparse: .../selinuxfs.c:1485:30: warning: incorrect type in assignment (different signedness) .../selinuxfs.c:1485:30: expected unsigned int * .../selinuxfs.c:1485:30: got int *[addressable] values .../selinuxfs.c:1402:48: warning: incorrect type in argument 3 (different signedness) .../selinuxfs.c:1402:48: expected int *values .../selinuxfs.c:1402:48: got unsigned int *bool_pending_values Signed-off-by: Christian Göttsche <> [PM: minor whitespace fixes, sparse output cleanup] Signed-off-by: Paul Moore <>
2022-08-30selinux: remove an unneeded variable in sel_make_class_dir_entries()ye xingchen
Return the value sel_make_perm_files() directly instead of storing it in another redundant variable. Reported-by: Zeal Robot <> Signed-off-by: ye xingchen <> [PM: subject line tweak] Signed-off-by: Paul Moore <>
2022-04-14selinux: don't sleep when CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE is truePaul Moore
Unfortunately commit 81200b0265b1 ("selinux: checkreqprot is deprecated, add some ssleep() discomfort") added a five second sleep during early kernel boot, e.g. start_kernel(), which could cause a "scheduling while atomic" panic. This patch fixes this problem by moving the sleep out of checkreqprot_set() and into sel_write_checkreqprot() so that we only sleep when the checkreqprot setting is set during runtime, after the kernel has booted. The error message remains the same in both cases. Fixes: 81200b0265b1 ("selinux: checkreqprot is deprecated, add some ssleep() discomfort") Reported-by: J. Bruce Fields <> Signed-off-by: Paul Moore <>
2022-04-04selinux: checkreqprot is deprecated, add some ssleep() discomfortPaul Moore
The checkreqprot functionality was disabled by default back in Linux v4.4 (2015) with commit 2a35d196c160e3 ("selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default") and it was officially marked as deprecated in Linux v5.7. It was always a bit of a hack to workaround very old userspace and to the best of our knowledge, the checkreqprot functionality has been disabled by Linux distributions for quite some time. This patch moves the deprecation messages from KERN_WARNING to KERN_ERR and adds a five second sleep to anyone using it to help draw their attention to the deprecation and provide a URL which helps explain things in more detail. Signed-off-by: Paul Moore <>
2022-04-04selinux: runtime disable is deprecated, add some ssleep() discomfortPaul Moore
We deprecated the SELinux runtime disable functionality in Linux v5.6, and it is time to get a bit more serious about removing it. Add a five second sleep to anyone using it to help draw their attention to the deprecation and provide a URL which helps explain things in more detail, including how to add kernel command line parameters to some of the more popular Linux distributions. Acked-by: Casey Schaufler <> Signed-off-by: Paul Moore <>
2022-03-02selinux: shorten the policy capability enum namesPaul Moore
The SELinux policy capability enum names are rather long and follow the "POLICYDB_CAPABILITY_XXX format". While the "POLICYDB_" prefix is helpful in tying the enums to other SELinux policy constants, macros, etc. there is no reason why we need to spell out "CAPABILITY" completely. Shorten "CAPABILITY" to "CAP" in order to make things a bit shorter and cleaner. Moving forward, the SELinux policy capability enum names should follow the "POLICYDB_CAP_XXX" format. Signed-off-by: Paul Moore <>
2022-01-25selinux: check return value of sel_make_avc_filesChristian Göttsche
sel_make_avc_files() might fail and return a negative errno value on memory allocation failures. Re-add the check of the return value, dropped in 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table"). Reported by clang-analyzer: security/selinux/selinuxfs.c:2129:2: warning: Value stored to 'ret' is never read [deadcode.DeadStores] ret = sel_make_avc_files(dentry); ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~ Fixes: 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table") Signed-off-by: Christian Göttsche <> Reviewed-by: Nick Desaulniers <> [PM: description line wrapping, added proper commit ref] Signed-off-by: Paul Moore <>
2021-04-27Merge tag 'selinux-pr-20210426' of ↵Linus Torvalds
git:// Pull selinux updates from Paul Moore: - Add support for measuring the SELinux state and policy capabilities using IMA. - A handful of SELinux/NFS patches to compare the SELinux state of one mount with a set of mount options. Olga goes into more detail in the patch descriptions, but this is important as it allows more flexibility when using NFS and SELinux context mounts. - Properly differentiate between the subjective and objective LSM credentials; including support for the SELinux and Smack. My clumsy attempt at a proper fix for AppArmor didn't quite pass muster so John is working on a proper AppArmor patch, in the meantime this set of patches shouldn't change the behavior of AppArmor in any way. This change explains the bulk of the diffstat beyond security/. - Fix a problem where we were not properly terminating the permission list for two SELinux object classes. * tag 'selinux-pr-20210426' of git:// selinux: add proper NULL termination to the secclass_map permissions smack: differentiate between subjective and objective task credentials selinux: clarify task subjective and objective credentials lsm: separate security_task_getsecid() into subjective and objective variants nfs: account for selinux security context when deciding to share superblock nfs: remove unneeded null check in nfs_fill_super() lsm,selinux: add new hook to compare new mount to an existing mount selinux: fix misspellings using codespell tool selinux: fix misspellings using codespell tool selinux: measure state and policy capabilities selinux: Allow context mounts for unpriviliged overlayfs
2021-03-18selinuxfs: unify policy load error reportingOndrej Mosnacek
Let's drop the pr_err()s from sel_make_policy_nodes() and just add one pr_warn_ratelimited() call to the sel_make_policy_nodes() error path in sel_write_load(). Changing from error to warning makes sense, since after 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs"), this error path no longer leads to a broken selinuxfs tree (it's just kept in the original state and policy load is aborted). I also added _ratelimited to be consistent with the other prtin in the same function (it's probably not necessary, but can't really hurt... there are likely more important error messages to be printed when filesystem entry creation starts erroring out). Suggested-by: Paul Moore <> Signed-off-by: Ondrej Mosnacek <> Signed-off-by: Paul Moore <>
2021-03-18selinux: fix variable scope issue in live sidtab conversionOndrej Mosnacek
Commit 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") moved the selinux_policy_commit() call out of security_load_policy() into sel_write_load(), which caused a subtle yet rather serious bug. The problem is that security_load_policy() passes a reference to the convert_params local variable to sidtab_convert(), which stores it in the sidtab, where it may be accessed until the policy is swapped over and RCU synchronized. Before 02a52c5c8c3b, selinux_policy_commit() was called directly from security_load_policy(), so the convert_params pointer remained valid all the way until the old sidtab was destroyed, but now that's no longer the case and calls to sidtab_context_to_sid() on the old sidtab after security_load_policy() returns may cause invalid memory accesses. This can be easily triggered using the stress test from commit ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance"): ``` function rand_cat() { echo $(( $RANDOM % 1024 )) } function do_work() { while true; do echo -n "system_u:system_r:kernel_t:s0:c$(rand_cat),c$(rand_cat)" \ >/sys/fs/selinux/context 2>/dev/null || true done } do_work >/dev/null & do_work >/dev/null & do_work >/dev/null & while load_policy; do echo -n .; sleep 0.1; done kill %1 kill %2 kill %3 ``` Fix this by allocating the temporary sidtab convert structures dynamically and passing them among the selinux_policy_{load,cancel,commit} functions. Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") Cc: Tested-by: Tyler Hicks <> Reviewed-by: Tyler Hicks <> Signed-off-by: Ondrej Mosnacek <> [PM: merge fuzz in security.h and services.c] Signed-off-by: Paul Moore <>
2021-03-18selinux: don't log MAC_POLICY_LOAD record on failed policy loadOndrej Mosnacek
If sel_make_policy_nodes() fails, we should jump to 'out', not 'out1', as the latter would incorrectly log an MAC_POLICY_LOAD audit record, even though the policy hasn't actually been reloaded. The 'out1' jump label now becomes unused and can be removed. Fixes: 02a52c5c8c3b ("selinux: move policy commit after updating selinuxfs") Cc: Signed-off-by: Ondrej Mosnacek <> Signed-off-by: Paul Moore <>
2021-03-08selinux: measure state and policy capabilitiesLakshmi Ramasubramanian
SELinux stores the configuration state and the policy capabilities in kernel memory. Changes to this data at runtime would have an impact on the security guarantees provided by SELinux. Measuring this data through IMA subsystem provides a tamper-resistant way for an attestation service to remotely validate it at runtime. Measure the configuration state and policy capabilities by calling the IMA hook ima_measure_critical_data(). To enable SELinux data measurement, the following steps are required: 1, Add "ima_policy=critical_data" to the kernel command line arguments to enable measuring SELinux data at boot time. For example, BOOT_IMAGE=/boot/vmlinuz-5.11.0-rc3+ root=UUID=fd643309-a5d2-4ed3-b10d-3c579a5fab2f ro nomodeset security=selinux ima_policy=critical_data 2, Add the following rule to /etc/ima/ima-policy measure func=CRITICAL_DATA label=selinux Sample measurement of SELinux state and policy capabilities: 10 2122...65d8 ima-buf sha256:13c2...1292 selinux-state 696e...303b Execute the following command to extract the measured data from the IMA's runtime measurements list: grep "selinux-state" /sys/kernel/security/integrity/ima/ascii_runtime_measurements | tail -1 | cut -d' ' -f 6 | xxd -r -p The output should be a list of key-value pairs. For example, initialized=1;enforcing=0;checkreqprot=1;network_peer_controls=1;open_perms=1;extended_socket_class=1;always_check_network=0;cgroup_seclabel=1;nnp_nosuid_transition=1;genfs_seclabel_symlinks=0; To verify the measurement is consistent with the current SELinux state reported on the system, compare the integer values in the following files with those set in the IMA measurement (using the following commands): - cat /sys/fs/selinux/enforce - cat /sys/fs/selinux/checkreqprot - cat /sys/fs/selinux/policy_capabilities/[capability_file] Note that the actual verification would be against an expected state and done on a separate system (likely an attestation server) requiring "initialized=1;enforcing=1;checkreqprot=0;" for a secure state and then whatever policy capabilities are actually set in the expected policy (which can be extracted from the policy itself via seinfo, for example). Signed-off-by: Lakshmi Ramasubramanian <> Suggested-by: Stephen Smalley <> Suggested-by: Paul Moore <> Signed-off-by: Paul Moore <>
2021-01-12selinux: mark some global variables __ro_after_initOndrej Mosnacek
All of these are never modified outside initcalls, so they can be __ro_after_init. Signed-off-by: Ondrej Mosnacek <> Signed-off-by: Paul Moore <>
2021-01-12selinux: make selinuxfs_mount staticOndrej Mosnacek
It is not referenced outside selinuxfs.c, so remove its extern header declaration and make it static. Signed-off-by: Ondrej Mosnacek <> Signed-off-by: Paul Moore <>
2020-09-15selinux: Add helper functions to get and set checkreqprotLakshmi Ramasubramanian
checkreqprot data member in selinux_state struct is accessed directly by SELinux functions to get and set. This could cause unexpected read or write access to this data member due to compiler optimizations and/or compiler's reordering of access to this field. Add helper functions to get and set checkreqprot data member in selinux_state struct. These helper functions use READ_ONCE and WRITE_ONCE macros to ensure atomic read or write of memory for this data member. Signed-off-by: Lakshmi Ramasubramanian <> Suggested-by: Stephen Smalley <> Suggested-by: Paul Moore <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-08-31selinux: simplify away security_policydb_len()Ondrej Mosnacek
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 <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-08-27selinux: move policy mutex to selinux_state, use in lockdep checksStephen Smalley
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 <> Reviewed-by: Ondrej Mosnacek <> Signed-off-by: Paul Moore <>
2020-08-21selinux: Create new booleans and class dirs out of treeDaniel Burgener
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 <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-08-21selinux: Standardize string literal usage for selinuxfs directory namesDaniel Burgener
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 <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-08-21selinux: Refactor selinuxfs directory populating functionsDaniel Burgener
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 <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-08-21selinux: Create function for selinuxfs directory cleanupDaniel Burgener
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 <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-08-17selinux: move policy commit after updating selinuxfsStephen Smalley
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 <> Signed-off-by: Paul Moore <>
2020-02-27selinux: remove unused initial SIDs and improve handlingStephen Smalley
Remove initial SIDs that have never been used or are no longer used by the kernel from its string table, which is also used to generate the SECINITSID_* symbols referenced in code. Update the code to gracefully handle the fact that these can now be NULL. Stop treating it as an error if a policy defines additional initial SIDs unknown to the kernel. Do not load unused initial SID contexts into the sidtab. Fix the incorrect usage of the name from the ocontext in error messages when loading initial SIDs since these are not presently written to the kernel policy and are therefore always NULL. After this change, it is possible to safely reclaim and reuse some of the unused initial SIDs without compatibility issues. Specifically, unused initial SIDs that were being assigned the same context as the unlabeled initial SID in policies can be reclaimed and reused for another purpose, with existing policies still treating them as having the unlabeled context and future policies having the option of mapping them to a more specific context. For example, this could have been used when the infiniband labeling support was introduced to define initial SIDs for the default pkey and endport SIDs similar to the handling of port/netif/node SIDs rather than always using SECINITSID_UNLABELED as the default. The set of safely reclaimable unused initial SIDs across all known policies is igmp_packet (13), icmp_socket (14), tcp_socket (15), kmod (24), policy (25), and scmp_packet (26); these initial SIDs were assigned the same context as unlabeled in all known policies including mls. If only considering non-mls policies (i.e. assuming that mls users always upgrade policy with their kernels), the set of safely reclaimable unused initial SIDs further includes file_labels (6), init (7), sysctl_modprobe (16), and sysctl_fs (18) through sysctl_dev (23). Adding new initial SIDs beyond SECINITSID_NUM to policy unfortunately became a fatal error in commit 24ed7fdae669 ("selinux: use separate table for initial SID lookup") and even before that it could cause problems on a policy reload (collision between the new initial SID and one allocated at runtime) ever since commit 42596eafdd75 ("selinux: load the initial SIDs upon every policy load") so we cannot safely start adding new initial SIDs to policies beyond SECINITSID_NUM (27) until such a time as all such kernels do not need to be supported and only those that include this commit are relevant. That is not a big deal since we haven't added a new initial SID since 2004 (v2.6.7) and we have plenty of unused ones we can reclaim if we truly need one. If we want to avoid the wasted storage in initial_sid_to_string[] and/or sidtab->isids[] for the unused initial SIDs, we could introduce an indirection between the kernel initial SID values and the policy initial SID values and just map the policy SID values in the ocontexts to the kernel values during policy_load_isids(). Originally I thought we'd do this by preserving the initial SID names in the kernel policy and creating a mapping at load time like we do for the security classes and permissions but that would require a new kernel policy format version and associated changes to libsepol/checkpolicy and I'm not sure it is justified. Simpler approach is just to create a fixed mapping table in the kernel from the existing fixed policy values to the kernel values. Less flexible but probably sufficient. A separate selinux userspace change was applied in to enable removal of most of the unused initial SID contexts from policies, but there is no dependency between that change and this one. That change permits removing all of the unused initial SID contexts from policy except for the fs and sysctl SID contexts. The initial SID declarations themselves would remain in policy to preserve the values of subsequent ones but the contexts can be dropped. If/when the kernel decides to reuse one of them, future policies can change the name and start assigning a context again without breaking compatibility. Here is how I would envision staging changes to the initial SIDs in a compatible manner after this commit is applied: 1. At any time after this commit is applied, the kernel could choose to reclaim one of the safely reclaimable unused initial SIDs listed above for a new purpose (i.e. replace its NULL entry in the initial_sid_to_string[] table with a new name and start using the newly generated SECINITSID_name symbol in code), and refpolicy could at that time rename its declaration of that initial SID to reflect its new purpose and start assigning it a context going forward. Existing/old policies would map the reclaimed initial SID to the unlabeled context, so that would be the initial default behavior until policies are updated. This doesn't depend on the selinux userspace change; it will work with existing policies and userspace. 2. In 6 months or so we'll have another SELinux userspace release that will include the libsepol/checkpolicy support for omitting unused initial SID contexts. 3. At any time after that release, refpolicy can make that release its minimum build requirement and drop the sid context statements (but not the sid declarations) for all of the unused initial SIDs except for fs and sysctl, which must remain for compatibility on policy reload with old kernels and for compatibility with kernels that were still using SECINITSID_SYSCTL (< 2.6.39). This doesn't depend on this kernel commit; it will work with previous kernels as well. 4. After N years for some value of N, refpolicy decides that it no longer cares about policy reload compatibility for kernels that predate this kernel commit, and refpolicy drops the fs and sysctl SID contexts from policy too (but retains the declarations). 5. After M years for some value of M, the kernel decides that it no longer cares about compatibility with refpolicies that predate step 4 (dropping the fs and sysctl SIDs), and those two SIDs also become safely reclaimable. This step is optional and need not ever occur unless we decide that the need to reclaim those two SIDs outweighs the compatibility cost. 6. After O years for some value of O, refpolicy decides that it no longer cares about policy load (not just reload) compatibility for kernels that predate this kernel commit, and both kernel and refpolicy can then start adding and using new initial SIDs beyond 27. This does not depend on the previous change (step 5) and can occur independent of it. Fixes: Signed-off-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-02-11selinux: convert cond_list to arrayOndrej Mosnacek
Since it is fixed-size after allocation and we know the size beforehand, using a plain old array is simpler and more efficient. While there, also fix signedness of some related variables/parameters. Signed-off-by: Ondrej Mosnacek <> Signed-off-by: Paul Moore <>
2020-02-10selinux: sel_avc_get_stat_idx should increase position indexVasily Averin
If seq_file .next function does not change position index, read after some lseek can generate unexpected output. $ dd if=/sys/fs/selinux/avc/cache_stats # usual output lookups hits misses allocations reclaims frees 817223 810034 7189 7189 6992 7037 1934894 1926896 7998 7998 7632 7683 1322812 1317176 5636 5636 5456 5507 1560571 1551548 9023 9023 9056 9115 0+1 records in 0+1 records out 189 bytes copied, 5,1564e-05 s, 3,7 MB/s $# read after lseek to midle of last line $ dd if=/sys/fs/selinux/avc/cache_stats bs=180 skip=1 dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset 056 9115 <<<< end of last line 1560571 1551548 9023 9023 9056 9115 <<< whole last line once again 0+1 records in 0+1 records out 45 bytes copied, 8,7221e-05 s, 516 kB/s $# read after lseek beyond end of of file $ dd if=/sys/fs/selinux/avc/cache_stats bs=1000 skip=1 dd: /sys/fs/selinux/avc/cache_stats: cannot skip to specified offset 1560571 1551548 9023 9023 9056 9115 <<<< generates whole last line 0+1 records in 0+1 records out 36 bytes copied, 9,0934e-05 s, 396 kB/s Signed-off-by: Vasily Averin <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-02-10Documentation,selinux: deprecate setting checkreqprot to 1Stephen Smalley
Deprecate setting the SELinux checkreqprot tunable to 1 via kernel parameter or /sys/fs/selinux/checkreqprot. Setting it to 0 is left intact for compatibility since Android and some Linux distributions do so for security and treat an inability to set it as a fatal error. Eventually setting it to 0 will become a no-op and the kernel will stop using checkreqprot's value internally altogether. checkreqprot was originally introduced as a compatibility mechanism for legacy userspace and the READ_IMPLIES_EXEC personality flag. However, if set to 1, it weakens security by allowing mappings to be made executable without authorization by policy. The default value for the SECURITY_SELINUX_CHECKREQPROT_VALUE config option was changed from 1 to 0 in commit 2a35d196c160e3 ("selinux: change CONFIG_SECURITY_SELINUX_CHECKREQPROT_VALUE default") and both Android and Linux distributions began explicitly setting /sys/fs/selinux/checkreqprot to 0 some time ago. Signed-off-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-01-07selinux: deprecate disabling SELinux and runtimePaul Moore
Deprecate the CONFIG_SECURITY_SELINUX_DISABLE functionality. The code was originally developed to make it easier for Linux distributions to support architectures where adding parameters to the kernel command line was difficult. Unfortunately, supporting runtime disable meant we had to make some security trade-offs when it came to the LSM hooks, as documented in the Kconfig help text: NOTE: selecting this option will disable the '__ro_after_init' kernel hardening feature for security hooks. Please consider using the selinux=0 boot parameter instead of enabling this option. Fortunately it looks as if that the original motivation for the runtime disable functionality is gone, and Fedora/RHEL appears to be the only major distribution enabling this capability at build time so we are now taking steps to remove it entirely from the kernel. The first step is to mark the functionality as deprecated and print an error when it is used (what this patch is doing). As Fedora/RHEL makes progress in transitioning the distribution away from runtime disable, we will introduce follow-up patches over several kernel releases which will block for increasing periods of time when the runtime disable is used. Finally we will remove the option entirely once we believe all users have moved to the kernel cmdline approach. Acked-by: Casey Schaufler <> Acked-by: Ondrej Mosnacek <> Acked-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2020-01-06selinuxfs: use scnprintf to get real length for inodeliuyang34
The return value of snprintf maybe over the size of TMPBUFLEN, use scnprintf instead in sel_read_class and sel_read_perm. Signed-off-by: liuyang34 <> [PM: cleaned up the description] Signed-off-by: Paul Moore <>
2019-12-18selinux: clean up selinux_enabled/disabled/enforcing_bootStephen Smalley
Rename selinux_enabled to selinux_enabled_boot to make it clear that it only reflects whether SELinux was enabled at boot. Replace the references to it in the MAC_STATUS audit log in sel_write_enforce() with hardcoded "1" values because this code is only reachable if SELinux is enabled and does not change its value, and update the corresponding MAC_STATUS audit log in sel_write_disable(). Stop clearing selinux_enabled in selinux_disable() since it is not used outside of initialization code that runs before selinux_disable() can be reached. Mark both selinux_enabled_boot and selinux_enforcing_boot as __initdata since they are only used in initialization code. Wrap the disabled field in the struct selinux_state with CONFIG_SECURITY_SELINUX_DISABLE since it is only used for runtime disable. Signed-off-by: Stephen Smalley <> Signed-off-by: Paul Moore <>
2019-12-09selinux: sidtab reverse lookup hash tableJeff Vander Stoep
This replaces the reverse table lookup and reverse cache with a hashtable which improves cache-miss reverse-lookup times from O(n) to O(1)* and maintains the same performance as a reverse cache hit. This reduces the time needed to add a new sidtab entry from ~500us to 5us on a Pixel 3 when there are ~10,000 sidtab entries. The implementation uses the kernel's generic hashtable API, It uses the context's string represtation as the hash source, and the kernels generic string hashing algorithm full_name_hash() to reduce the string to a 32 bit value. This change also maintains the improvement introduced in commit ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance") which removed the need to keep the current sidtab locked during policy reload. It does however introduce periodic locking of the target sidtab while converting the hashtable. Sidtab entries are never modified or removed, so the context struct stored in the sid_to_context tree can also be used for the context_to_sid hashtable to reduce memory usage. This bug was reported by: - On the selinux bug tracker. BUG: kernel softlockup due to too many SIDs/contexts #37 - Jovana Knezevic on Android's bugtracker. Bug: 140252993 "During multi-user performance testing, we create and remove users many times. selinux_android_restorecon_pkgdir goes from 1ms to over 20ms after about 200 user creations and removals. Accumulated over ~280 packages, that adds a significant time to user creation, making perf benchmarks unreliable." * Hashtable lookup is only O(1) when n < the number of buckets. Signed-off-by: Jeff Vander Stoep <> Reported-by: Stephen Smalley <> Reported-by: Jovana Knezevic <> Reviewed-by: Stephen Smalley <> Tested-by: Stephen Smalley <> [PM: subj tweak, removed changelog from patch description] Signed-off-by: Paul Moore <>
2019-10-01selinux: remove load size limitzhanglin
Load size was limited to 64MB, this was legacy limitation due to vmalloc() which was removed a while ago. Signed-off-by: zhanglin <> [PM: removed comments in the description about 'real world use cases'] Signed-off-by: Paul Moore <>
2019-07-19Merge branch 'work.mount0' of ↵Linus Torvalds
git:// Pull vfs mount updates from Al Viro: "The first part of mount updates. Convert filesystems to use the new mount API" * 'work.mount0' of git:// (63 commits) mnt_init(): call shmem_init() unconditionally constify ksys_mount() string arguments don't bother with registering rootfs init_rootfs(): don't bother with init_ramfs_fs() vfs: Convert smackfs to use the new mount API vfs: Convert selinuxfs to use the new mount API vfs: Convert securityfs to use the new mount API vfs: Convert apparmorfs to use the new mount API vfs: Convert openpromfs to use the new mount API vfs: Convert xenfs to use the new mount API vfs: Convert gadgetfs to use the new mount API vfs: Convert oprofilefs to use the new mount API vfs: Convert ibmasmfs to use the new mount API vfs: Convert qib_fs/ipathfs to use the new mount API vfs: Convert efivarfs to use the new mount API vfs: Convert configfs to use the new mount API vfs: Convert binfmt_misc to use the new mount API convenience helper: get_tree_single() convenience helper get_tree_nodev() vfs: Kill sget_userns() ...
2019-07-08Merge branch 'next-integrity' of ↵Linus Torvalds
git:// Pull integrity updates from Mimi Zohar: "Bug fixes, code clean up, and new features: - IMA policy rules can be defined in terms of LSM labels, making the IMA policy dependent on LSM policy label changes, in particular LSM label deletions. The new environment, in which IMA-appraisal is being used, frequently updates the LSM policy and permits LSM label deletions. - Prevent an mmap'ed shared file opened for write from also being mmap'ed execute. In the long term, making this and other similar changes at the VFS layer would be preferable. - The IMA per policy rule template format support is needed for a couple of new/proposed features (eg. kexec boot command line measurement, appended signatures, and VFS provided file hashes). - Other than the "boot-aggregate" record in the IMA measuremeent list, all other measurements are of file data. Measuring and storing the kexec boot command line in the IMA measurement list is the first buffer based measurement included in the measurement list" * 'next-integrity' of git:// integrity: Introduce struct evm_xattr ima: Update MAX_TEMPLATE_NAME_LEN to fit largest reasonable definition KEXEC: Call ima_kexec_cmdline to measure the boot command line args IMA: Define a new template field buf IMA: Define a new hook to measure the kexec boot command line arguments IMA: support for per policy rule template formats integrity: Fix __integrity_init_keyring() section mismatch ima: Use designated initializers for struct ima_event_data ima: use the lsm policy update notifier LSM: switch to blocking policy update notifiers x86/ima: fix the Kconfig dependency for IMA_ARCH_POLICY ima: Make arch_policy_entry static ima: prevent a file already mmap'ed write to be mmap'ed execute x86/ima: check EFI SetupMode too
2019-07-04vfs: Convert selinuxfs to use the new mount APIDavid Howells
Convert the selinuxfs filesystem to the new internal mount API as the old one will be obsoleted and removed. This allows greater flexibility in communication of mount parameters between userspace, the VFS and the filesystem. See Documentation/filesystems/mount_api.txt for more information. Signed-off-by: David Howells <> cc: Paul Moore <> cc: Stephen Smalley <> cc: Eric Paris <> cc: cc: Signed-off-by: Al Viro <>
2019-06-14LSM: switch to blocking policy update notifiersJanne Karhunen
Atomic policy updaters are not very useful as they cannot usually perform the policy updates on their own. Since it seems that there is no strict need for the atomicity, switch to the blocking variant. While doing so, rename the functions accordingly. Signed-off-by: Janne Karhunen <> Acked-by: Paul Moore <> Acked-by: James Morris <> Signed-off-by: Mimi Zohar <>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation version 2 extracted by the scancode license scanner the SPDX license identifier GPL-2.0-only has been chosen to replace the boilerplate/reference in 135 file(s). Signed-off-by: Thomas Gleixner <> Reviewed-by: Allison Randal <> Cc: Link: Signed-off-by: Greg Kroah-Hartman <>
2019-01-08SELinux: Abstract use of inode security blobCasey Schaufler
Don't use the inode->i_security pointer directly. Provide a helper function that provides the security blob pointer. Signed-off-by: Casey Schaufler <> Reviewed-by: Kees Cook <> Signed-off-by: Kees Cook <>
2018-08-15Merge tag 'selinux-pr-20180814' of ↵Linus Torvalds
git:// Pull SELinux updates from Paul Moore: "There are 16 patches in here but really only one that is of any significance. That one patch is by nixiaoming and fixes a few places where we were not properly cleaning up dentry and inode objects in the selinuxfs error handling code. The rest are either printk->pr_* conversions, constification tweaks, and a minor tweak to MAINTAINERS. Everything passes the selinux-testsuite and looks to merge cleanly against your master branch" * tag 'selinux-pr-20180814' of git:// selinux: cleanup dentry and inodes on error in selinuxfs selinux: constify write_op[] selinux: Cleanup printk logging in netnode selinux: Cleanup printk logging in avc selinux: Cleanup printk logging in netif selinux: Cleanup printk logging in netport selinux: Cleanup printk logging in sidtab selinux: Cleanup printk logging in netlink selinux: Cleanup printk logging in selinuxfs selinux: Cleanup printk logging in services selinux: Cleanup printk logging in avtab selinux: Cleanup printk logging in hooks selinux: Cleanup printk logging in policydb selinux: Cleanup printk logging in ebitmap selinux: Cleanup printk logging in conditional MAINTAINERS: update the LSM and SELinux subsystems
2018-08-07selinux: cleanup dentry and inodes on error in selinuxfsnixiaoming
If the resource requested by d_alloc_name is not added to the linked list through d_add, then dput needs to be called to release the subsequent abnormal branch to avoid resource leakage. Add missing dput to selinuxfs.c Signed-off-by: nixiaoming <> [PM: tweak the subject line] Signed-off-by: Paul Moore <>
2018-07-17selinux: constify write_op[]Eric Biggers
write_op[] is never modified, so make it 'const'. Signed-off-by: Eric Biggers <> Signed-off-by: Paul Moore <>
2018-06-30Merge tag 'selinux-pr-20180629' of ↵Linus Torvalds
git:// Pull selinux fix from Paul Moore: "One fairly straightforward patch to fix a longstanding issue where a process could stall while accessing files in selinuxfs and block everyone else due to a held mutex. The patch passes all our tests and looks to apply cleanly to your current tree" * tag 'selinux-pr-20180629' of git:// selinux: move user accesses in selinuxfs out of locked regions
2018-06-28selinux: move user accesses in selinuxfs out of locked regionsJann Horn
If a user is accessing a file in selinuxfs with a pointer to a userspace buffer that is backed by e.g. a userfaultfd, the userspace access can stall indefinitely, which can block fsi->mutex if it is held. For sel_read_policy(), remove the locking, since this method doesn't seem to access anything that requires locking. For sel_read_bool(), move the user access below the locked region. For sel_write_bool() and sel_commit_bools_write(), move the user access up above the locked region. Cc: Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Jann Horn <> Acked-by: Stephen Smalley <> [PM: removed an unused variable in sel_read_policy()] Signed-off-by: Paul Moore <>
2018-06-19selinux: Cleanup printk logging in selinuxfspeter enderborg
Replace printk with pr_* to avoid checkpatch warnings. Signed-off-by: Peter Enderborg <> Signed-off-by: Paul Moore <>
2018-06-06Merge tag 'audit-pr-20180605' of ↵Linus Torvalds
git:// Pull audit updates from Paul Moore: "Another reasonable chunk of audit changes for v4.18, thirteen patches in total. The thirteen patches can mostly be broken down into one of four categories: general bug fixes, accessor functions for audit state stored in the task_struct, negative filter matches on executable names, and extending the (relatively) new seccomp logging knobs to the audit subsystem. The main driver for the accessor functions from Richard are the changes we're working on to associate audit events with containers, but I think they have some standalone value too so I figured it would be good to get them in now. The seccomp/audit patches from Tyler apply the seccomp logging improvements from a few releases ago to audit's seccomp logging; starting with this patchset the changes in /proc/sys/kernel/seccomp/actions_logged should apply to both the standard kernel logging and audit. As usual, everything passes the audit-testsuite and it happens to merge cleanly with your tree" [ Heh, except it had trivial merge conflicts with the SELinux tree that also came in from Paul - Linus ] * tag 'audit-pr-20180605' of git:// audit: Fix wrong task in comparison of session ID audit: use existing session info function audit: normalize loginuid read access audit: use new audit_context access funciton for seccomp_actions_logged audit: use inline function to set audit context audit: use inline function to get audit context audit: convert sessionid unset to a macro seccomp: Don't special case audited processes when logging seccomp: Audit attempts to modify the actions_logged sysctl seccomp: Configurable separator for the actions_logged string seccomp: Separate read and write code for actions_logged sysctl audit: allow not equal op for audit by executable audit: add syscall information to FEATURE_CHANGE records
2018-05-14audit: use inline function to get audit contextRichard Guy Briggs
Recognizing that the audit context is an internal audit value, use an access function to retrieve the audit context pointer for the task rather than reaching directly into the task struct to get it. Signed-off-by: Richard Guy Briggs <> [PM: merge fuzz in auditsc.c and selinuxfs.c, fixes] Signed-off-by: Paul Moore <>
2018-04-17audit: normalize MAC_POLICY_LOAD recordRichard Guy Briggs
The audit MAC_POLICY_LOAD record had redundant dangling keywords and was missing information about which LSM was responsible and its completion status. While this record is only issued on success, the parser expects the res= field to be present. Old record: type=MAC_POLICY_LOAD msg=audit(1479299795.404:43): policy loaded auid=0 ses=1 Delete the redundant dangling keywords, add the lsm= field and the res= field. New record: type=MAC_POLICY_LOAD msg=audit(1523293846.204:894): auid=0 ses=1 lsm=selinux res=1 See: Signed-off-by: Richard Guy Briggs <> Signed-off-by: Paul Moore <>
2018-04-17audit: normalize MAC_STATUS recordRichard Guy Briggs
There were two formats of the audit MAC_STATUS record, one of which was more standard than the other. One listed enforcing status changes and the other listed enabled status changes with a non-standard label. In addition, the record was missing information about which LSM was responsible and the operation's completion status. While this record is only issued on success, the parser expects the res= field to be present. old enforcing/permissive: type=MAC_STATUS msg=audit(1523312831.378:24514): enforcing=0 old_enforcing=1 auid=0 ses=1 old enable/disable: type=MAC_STATUS msg=audit(1523312831.378:24514): selinux=0 auid=0 ses=1 List both sets of status and old values and add the lsm= field and the res= field. Here is the new format: type=MAC_STATUS msg=audit(1523293828.657:891): enforcing=0 old_enforcing=1 auid=0 ses=1 enabled=1 old-enabled=1 lsm=selinux res=1 This record already accompanied a SYSCALL record. See: Signed-off-by: Richard Guy Briggs <> [PM: 80-char fixes, merge fuzz, use new SELinux state functions] Signed-off-by: Paul Moore <>
2018-04-16security: selinux: Change return type to vm_fault_tSouptick Joarder
Use new return type vm_fault_t for fault handler in struct vm_operations_struct. Signed-off-by: Souptick Joarder <> Reviewed-by: Matthew Wilcox <> Signed-off-by: Paul Moore <>
2018-04-09selinux: fix missing dput() before selinuxfs unmountStephen Smalley
Commit 0619f0f5e36f ("selinux: wrap selinuxfs state") triggers a BUG when SELinux is runtime-disabled (i.e. systemd or equivalent disables SELinux before initial policy load via /sys/fs/selinux/disable based on /etc/selinux/config SELINUX=disabled). This does not manifest if SELinux is disabled via kernel command line argument or if SELinux is enabled (permissive or enforcing). Before: SELinux: Disabled at runtime. BUG: Dentry 000000006d77e5c7{i=17,n=null} still in use (1) [unmount of selinuxfs selinuxfs] After: SELinux: Disabled at runtime. Fixes: 0619f0f5e36f ("selinux: wrap selinuxfs state") Reported-by: Tetsuo Handa <> Reported-by: Dmitry Vyukov <> Signed-off-by: Stephen Smalley <> Signed-off-by: Linus Torvalds <>
2018-03-20selinux: wrap AVC stateStephen Smalley
Wrap the AVC state within the selinux_state structure and pass it explicitly to all AVC functions. The AVC private state is encapsulated in a selinux_avc structure that is referenced from the selinux_state. This change should have no effect on SELinux behavior or APIs (userspace or LSM). Signed-off-by: Stephen Smalley <> Reviewed-by: James Morris <> Signed-off-by: Paul Moore <>