path: root/security/selinux/ss/services.c (follow)
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2020-01-16selinux: do not allocate ancillary buffer on first loadOndrej Mosnacek1-15/+13
In security_load_policy(), we can defer allocating the newpolicydb ancillary array to after checking state->initialized, thereby avoiding the pointless allocation when loading policy the first time. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: merged portions by hand] Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2020-01-10selinux: treat atomic flags more carefullyOndrej Mosnacek1-19/+19
The disabled/enforcing/initialized flags are all accessed concurrently by threads so use the appropriate accessors that ensure atomicity and document that it is expected. Use smp_load/acquire...() helpers (with memory barriers) for the initialized flag, since it gates access to the rest of the state structures. Note that the disabled flag is currently not used for anything other than avoiding double disable, but it will be used for bailing out of hooks once security_delete_hooks() is removed. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: James Morris <jamorris@linux.microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-24selinux: remove set but not used variable 'sidtab'YueHaibing1-8/+0
security/selinux/ss/services.c: In function security_port_sid: security/selinux/ss/services.c:2346:17: warning: variable sidtab set but not used [-Wunused-but-set-variable] security/selinux/ss/services.c: In function security_ib_endport_sid: security/selinux/ss/services.c:2435:17: warning: variable sidtab set but not used [-Wunused-but-set-variable] security/selinux/ss/services.c: In function security_netif_sid: security/selinux/ss/services.c:2480:17: warning: variable sidtab set but not used [-Wunused-but-set-variable] security/selinux/ss/services.c: In function security_fs_use: security/selinux/ss/services.c:2831:17: warning: variable sidtab set but not used [-Wunused-but-set-variable] Since commit 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table") 'sidtab' is not used any more, so remove it. Reported-by: Hulk Robot <hulkci@huawei.com> Signed-off-by: YueHaibing <yuehaibing@huawei.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-23selinux: ensure the policy has been loaded before reading the sidtab statsPaul Moore1-0/+6
Check to make sure we have loaded a policy before we query the sidtab's hash stats. Failure to do so could result in a kernel panic/oops due to a dereferenced NULL pointer. Fixes: 66f8e2f03c02 ("selinux: sidtab reverse lookup hash table") Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-09selinux: cache the SID -> context string translationOndrej Mosnacek1-54/+84
Translating a context struct to string can be quite slow, especially if the context has a lot of category bits set. This can cause quite noticeable performance impact in situations where the translation needs to be done repeatedly. A common example is a UNIX datagram socket with the SO_PASSSEC option enabled, which is used e.g. by systemd-journald when receiving log messages via datagram socket. This scenario can be reproduced with: cat /dev/urandom | base64 | logger & timeout 30s perf record -p $(pidof systemd-journald) -a -g kill %1 perf report -g none --pretty raw | grep security_secid_to_secctx Before the caching introduced by this patch, computing the context string (security_secid_to_secctx() function) takes up ~65% of systemd-journald's CPU time (assuming a context with 1024 categories set and Fedora x86_64 release kernel configs). After this patch (assuming near-perfect cache hit ratio) this overhead is reduced to just ~2%. This patch addresses the issue by caching a certain number (compile-time configurable) of recently used context strings to speed up repeated translations of the same context, while using only a small amount of memory. The cache is integrated into the existing sidtab table by adding a field to each entry, which when not NULL contains an RCU-protected pointer to a cache entry containing the cached string. The cache entries are kept in a linked list sorted according to how recently they were used. On a cache miss when the cache is full, the least recently used entry is removed to make space for the new entry. The patch migrates security_sid_to_context_core() to use the cache (also a few other functions where it was possible without too much fuss, but these mostly use the translation for logging in case of error, which is rare). Link: https://bugzilla.redhat.com/show_bug.cgi?id=1733259 Cc: Michal Sekletar <msekleta@redhat.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Tested-by: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: Paul E. McKenney <paulmck@kernel.org> [PM: lots of merge fixups due to collisions with other sidtab patches] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-12-09selinux: sidtab reverse lookup hash tableJeff Vander Stoep1-24/+72
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 https://github.com/SELinuxProject/selinux-kernel/issues/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 <jeffv@google.com> Reported-by: Stephen Smalley <sds@tycho.nsa.gov> Reported-by: Jovana Knezevic <jovanak@google.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Tested-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: subj tweak, removed changelog from patch description] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-10-08Merge tag 'selinux-pr-20191007' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-1/+8
Pull selinuxfix from Paul Moore: "One patch to ensure we don't copy bad memory up into userspace" * tag 'selinux-pr-20191007' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: fix context string corruption in convert_context()
2019-10-03selinux: fix context string corruption in convert_context()Ondrej Mosnacek1-1/+8
string_to_context_struct() may garble the context string, so we need to copy back the contents again from the old context struct to avoid storing the corrupted context. Since string_to_context_struct() tokenizes (and therefore truncates) the context string and we are later potentially copying it with kstrdup(), this may eventually cause pieces of uninitialized kernel memory to be disclosed to userspace (when copying to userspace based on the stored length and not the null character). How to reproduce on Fedora and similar: # dnf install -y memcached # systemctl start memcached # semodule -d memcached # load_policy # load_policy # systemctl stop memcached # ausearch -m AVC type=AVC msg=audit(1570090572.648:313): avc: denied { signal } for pid=1 comm="systemd" scontext=system_u:system_r:init_t:s0 tcontext=system_u:object_r:unlabeled_t:s0 tclass=process permissive=0 trawcon=73797374656D5F75007400000000000070BE6E847296FFFF726F6D000096FFFF76 Cc: stable@vger.kernel.org Reported-by: Milos Malik <mmalik@redhat.com> Fixes: ee1a84fdfeed ("selinux: overhaul sidtab to fix bug and improve performance") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-09-23Merge tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-3/+3
Pull selinux updates from Paul Moore: - Add LSM hooks, and SELinux access control hooks, for dnotify, fanotify, and inotify watches. This has been discussed with both the LSM and fs/notify folks and everybody is good with these new hooks. - The LSM stacking changes missed a few calls to current_security() in the SELinux code; we fix those and remove current_security() for good. - Improve our network object labeling cache so that we always return the object's label, even when under memory pressure. Previously we would return an error if we couldn't allocate a new cache entry, now we always return the label even if we can't create a new cache entry for it. - Convert the sidtab atomic_t counter to a normal u32 with READ/WRITE_ONCE() and memory barrier protection. - A few patches to policydb.c to clean things up (remove forward declarations, long lines, bad variable names, etc) * tag 'selinux-pr-20190917' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: lsm: remove current_security() selinux: fix residual uses of current_security() for the SELinux blob selinux: avoid atomic_t usage in sidtab fanotify, inotify, dnotify, security: add security hook for fs notifications selinux: always return a secid from the network caches if we find one selinux: policydb - rename type_val_to_struct_array selinux: policydb - fix some checkpatch.pl warnings selinux: shuffle around policydb.c to get rid of forward declarations
2019-08-05selinux: policydb - rename type_val_to_struct_arrayOndrej Mosnacek1-3/+3
The name is overly long and inconsistent with the other *_val_to_struct members. Dropping the "_array" prefix makes the code easier to read and gets rid of one line over 80 characters warning. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-07-08Merge tag 'selinux-pr-20190702' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-14/+19
Pull selinux updates from Paul Moore: "Like the audit pull request this is a little early due to some upcoming vacation plans and uncertain network access while I'm away. Also like the audit PR, the list of patches here is pretty minor, the highlights include: - Explicitly use __le variables to make sure "sparse" can verify proper byte endian handling. - Remove some BUG_ON()s that are no longer needed. - Allow zero-byte writes to the "keycreate" procfs attribute without requiring key:create to make it easier for userspace to reset the keycreate label. - Consistently log the "invalid_context" field as an untrusted string in the AUDIT_SELINUX_ERR audit records" * tag 'selinux-pr-20190702' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: format all invalid context as untrusted selinux: fix empty write to keycreate file selinux: remove some no-op BUG_ONs selinux: provide __le variables explicitly
2019-07-01selinux: format all invalid context as untrustedRichard Guy Briggs1-10/+19
The userspace tools expect all fields of the same name to be logged consistently with the same encoding. Since the invalid_context fields contain untrusted strings in selinux_inode_setxattr() and selinux_setprocattr(), encode all instances of this field the same way as though they were untrusted even though compute_sid_handle_invalid_context() and security_sid_mls_copy() are trusted. Please see github issue https://github.com/linux-audit/audit-kernel/issues/57 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-06-05treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 372Thomas Gleixner1-3/+1
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 <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190531081036.435762997@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-21selinux: remove some no-op BUG_ONsOndrej Mosnacek1-4/+0
Since acdf52d97f82 ("selinux: convert to kvmalloc"), these check whether an address-of value is NULL, which is pointless. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-25selinux: remove useless assignmentsOndrej Mosnacek1-5/+2
The code incorrectly assigned directly to the variables instead of the values they point to. Since the values are already set to NULL/0 at the beginning of the function, we can simply remove these useless assignments. Reported-by: Hariprasad Kelam <hariprasad.kelam@gmail.com> Fixes: fede148324c3 ("selinux: log invalid contexts in AVCs") Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> [PM: removed a bad comment that was causing compiler warnings] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-03-12selinux: convert to kvmallocKent Overstreet1-15/+7
The flex arrays were being used for constant sized arrays, so there's no benefit to using flex_arrays over something simpler. Link: http://lkml.kernel.org/r/20181217131929.11727-4-kent.overstreet@gmail.com Signed-off-by: Kent Overstreet <kent.overstreet@gmail.com> Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Neil Horman <nhorman@tuxdriver.com> Cc: Pravin B Shelar <pshelar@ovn.org> Cc: Shaohua Li <shli@kernel.org> Cc: Vlad Yasevich <vyasevich@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-07Merge tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/auditLinus Torvalds1-2/+1
Pull audit updates from Paul Moore: "A lucky 13 audit patches for v5.1. Despite the rather large diffstat, most of the changes are from two bug fix patches that move code from one Kconfig option to another. Beyond that bit of churn, the remaining changes are largely cleanups and bug-fixes as we slowly march towards container auditing. It isn't all boring though, we do have a couple of new things: file capabilities v3 support, and expanded support for filtering on filesystems to solve problems with remote filesystems. All changes pass the audit-testsuite. Please merge for v5.1" * tag 'audit-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: audit: mark expected switch fall-through audit: hide auditsc_get_stamp and audit_serial prototypes audit: join tty records to their syscall audit: remove audit_context when CONFIG_ AUDIT and not AUDITSYSCALL audit: remove unused actx param from audit_rule_match audit: ignore fcaps on umount audit: clean up AUDITSYSCALL prototypes and stubs audit: more filter PATH records keyed on filesystem magic audit: add support for fcaps v3 audit: move loginuid and sessionid from CONFIG_AUDITSYSCALL to CONFIG_AUDIT audit: add syscall information to CONFIG_CHANGE records audit: hand taken context to audit_kill_trees for syscall logging audit: give a clue what CONFIG_CHANGE op was involved
2019-03-07Merge tag 'selinux-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinuxLinus Torvalds1-5/+32
Pull SELinux updates from Paul Moore: "Nine SELinux patches for v5.1, all bug fixes. As far as I'm concerned, nothing really jumps out as risky or special to me, but each commit has a decent description so you can judge for yourself. As usual, everything passes the selinux-testsuite; please merge for v5.1" * tag 'selinux-pr-20190305' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/selinux: selinux: fix avc audit messages selinux: replace BUG_ONs with WARN_ONs in avc.c selinux: log invalid contexts in AVCs selinux: replace some BUG_ON()s with a WARN_ON() selinux: inline some AVC functions used only once selinux: do not override context on context mounts selinux: never allow relabeling on context mounts selinux: stop passing MAY_NOT_BLOCK to the AVC upon follow_link selinux: avoid silent denials in permissive mode under RCU walk
2019-01-31audit: remove unused actx param from audit_rule_matchRichard Guy Briggs1-2/+1
The audit_rule_match() struct audit_context *actx parameter is not used by any in-tree consumers (selinux, apparmour, integrity, smack). The audit context is an internal audit structure that should only be accessed by audit accessor functions. It was part of commit 03d37d25e0f9 ("LSM/Audit: Introduce generic Audit LSM hooks") but appears to have never been used. Remove it. Please see the github issue https://github.com/linux-audit/audit-kernel/issues/107 Signed-off-by: Richard Guy Briggs <rgb@redhat.com> [PM: fixed the referenced commit title] Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-25selinux: log invalid contexts in AVCsOndrej Mosnacek1-5/+32
In case a file has an invalid context set, in an AVC record generated upon access to such file, the target context is always reported as unlabeled. This patch adds new optional fields to the AVC record (srawcon and trawcon) that report the actual context string if it differs from the one reported in scontext/tcontext. This is useful for diagnosing SELinux denials involving invalid contexts. To trigger an AVC that illustrates this situation: # setenforce 0 # touch /tmp/testfile # setfattr -n security.selinux -v system_u:object_r:banana_t:s0 /tmp/testfile # runcon system_u:system_r:sshd_t:s0 cat /tmp/testfile AVC before: type=AVC msg=audit(1547801083.248:11): avc: denied { open } for pid=1149 comm="cat" path="/tmp/testfile" dev="tmpfs" ino=6608 scontext=system_u:system_r:sshd_t:s0 tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=file permissive=1 AVC after: type=AVC msg=audit(1547801083.248:11): avc: denied { open } for pid=1149 comm="cat" path="/tmp/testfile" dev="tmpfs" ino=6608 scontext=system_u:system_r:sshd_t:s0 tcontext=system_u:object_r:unlabeled_t:s15:c0.c1023 tclass=file permissive=1 trawcon=system_u:object_r:banana_t:s0 Note that it is also possible to encounter this situation with the 'scontext' field - e.g. when a new policy is loaded while a process is running, whose context is not valid in the new policy. Link: https://bugzilla.redhat.com/show_bug.cgi?id=1135683 Cc: Daniel Walsh <dwalsh@redhat.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2019-01-08SELinux: Remove unused selinux_is_enabledCasey Schaufler1-1/+0
There are no longer users of selinux_is_enabled(). Remove it. As selinux_is_enabled() is the only reason for include/linux/selinux.h remove that as well. Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> Reviewed-by: Kees Cook <keescook@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org>
2018-12-05selinux: overhaul sidtab to fix bug and improve performanceOndrej Mosnacek1-71/+51
Before this patch, during a policy reload the sidtab would become frozen and trying to map a new context to SID would be unable to add a new entry to sidtab and fail with -ENOMEM. Such failures are usually propagated into userspace, which has no way of distignuishing them from actual allocation failures and thus doesn't handle them gracefully. Such situation can be triggered e.g. by the following reproducer: while true; do load_policy; echo -n .; sleep 0.1; done & for (( i = 0; i < 1024; i++ )); do runcon -l s0:c$i echo -n x || break # or: # chcon -l s0:c$i <some_file> || break done This patch overhauls the sidtab so it doesn't need to be frozen during policy reload, thus solving the above problem. The new SID table leverages the fact that SIDs are allocated sequentially and are never invalidated and stores them in linear buckets indexed by a tree structure. This brings several advantages: 1. Fast SID -> context lookup - this lookup can now be done in logarithmic time complexity (usually in less than 4 array lookups) and can still be done safely without locking. 2. No need to re-search the whole table on reverse lookup miss - after acquiring the spinlock only the newly added entries need to be searched, which means that reverse lookups that end up inserting a new entry are now about twice as fast. 3. No need to freeze sidtab during policy reload - it is now possible to handle insertion of new entries even during sidtab conversion. The tree structure of the new sidtab is able to grow automatically to up to about 2^31 entries (at which point it should not have more than about 4 tree levels). The old sidtab had a theoretical capacity of almost 2^32 entries, but half of that is still more than enough since by that point the reverse table lookups would become unusably slow anyway... The number of entries per tree node is selected automatically so that each node fits into a single page, which should be the easiest size for kmalloc() to handle. Note that the cache for reverse lookup is preserved with equivalent logic. The only difference is that instead of storing pointers to the hash table nodes it stores just the indices of the cached entries. The new cache ensures that the indices are loaded/stored atomically, but it still has the drawback that concurrent cache updates may mess up the contents of the cache. Such situation however only reduces its effectivity, not the correctness of lookups. Tested by selinux-testsuite and thoroughly tortured by this simple stress test: ``` 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 ``` Link: https://github.com/SELinuxProject/selinux-kernel/issues/38 Reported-by: Orion Poplawski <orion@nwra.com> Reported-by: Li Kun <hw.likun@huawei.com> Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: most of sidtab.c merged by hand due to conflicts] [PM: checkpatch fixes in mls.c, services.c, sidtab.c] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-12-05selinux: use separate table for initial SID lookupOndrej Mosnacek1-38/+50
This moves handling of initial SIDs into a separate table. Note that the SIDs stored in the main table are now shifted by SECINITSID_NUM and converted to/from the actual SIDs transparently by helper functions. This change doesn't make much sense on its own, but it simplifies further sidtab overhaul in a succeeding patch. Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Reviewed-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: fixed some checkpatch warnings on line length, whitespace] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-26selinux: make "selinux_policycap_names[]" const char *Alexey Dobriyan1-1/+1
Those strings aren't written. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-11-20selinux: refactor sidtab conversionOndrej Mosnacek1-21/+1
This is a purely cosmetic change that encapsulates the three-step sidtab conversion logic (shutdown -> clone -> map) into a single function defined in sidtab.c (as opposed to services.c). Signed-off-by: Ondrej Mosnacek <omosnace@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: whitespaces fixes to make checkpatch happy] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-09-05selinux: refactor mls_context_to_sid() and make it stricterJann Horn1-8/+4
The intended behavior change for this patch is to reject any MLS strings that contain (trailing) garbage if p->mls_enabled is true. As suggested by Paul Moore, change mls_context_to_sid() so that the two parts of the range are extracted before the rest of the parsing. Because now we don't have to scan for two different separators simultaneously everywhere, we can actually switch to strchr() everywhere instead of the open-coded loops that scan for two separators at once. mls_context_to_sid() used to signal how much of the input string was parsed by updating `*scontext`. However, there is actually no case in which mls_context_to_sid() only parses a subset of the input and still returns a success (other than the buggy case with a second '-' in which it incorrectly claims to have consumed the entire string). Turn `scontext` into a simple pointer argument and stop redundantly checking whether the entire input was consumed in string_to_context_struct(). This also lets us remove the `scontext_len` argument from `string_to_context_struct()`. Signed-off-by: Jann Horn <jannh@google.com> [PM: minor merge fuzz in convert_context()] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-06-19selinux: Cleanup printk logging in servicespeter enderborg1-36/+35
Replace printk with pr_* to avoid checkpatch warnings. Signed-off-by: Peter Enderborg <peter.enderborg@sony.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-06-12treewide: kzalloc() -> kcalloc()Kees Cook1-1/+1
The kzalloc() function has a 2-factor argument form, kcalloc(). This patch replaces cases of: kzalloc(a * b, gfp) with: kcalloc(a * b, gfp) as well as handling cases of: kzalloc(a * b * c, gfp) with: kzalloc(array3_size(a, b, c), gfp) as it's slightly less ugly than: kzalloc_array(array_size(a, b), c, gfp) This does, however, attempt to ignore constant size factors like: kzalloc(4 * 1024, gfp) though any constants defined via macros get caught up in the conversion. Any factors with a sizeof() of "unsigned char", "char", and "u8" were dropped, since they're redundant. The Coccinelle script used for this was: // Fix redundant parens around sizeof(). @@ type TYPE; expression THING, E; @@ ( kzalloc( - (sizeof(TYPE)) * E + sizeof(TYPE) * E , ...) | kzalloc( - (sizeof(THING)) * E + sizeof(THING) * E , ...) ) // Drop single-byte sizes and redundant parens. @@ expression COUNT; typedef u8; typedef __u8; @@ ( kzalloc( - sizeof(u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(__u8) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(unsigned char) * (COUNT) + COUNT , ...) | kzalloc( - sizeof(u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(__u8) * COUNT + COUNT , ...) | kzalloc( - sizeof(char) * COUNT + COUNT , ...) | kzalloc( - sizeof(unsigned char) * COUNT + COUNT , ...) ) // 2-factor product with sizeof(type/expression) and identifier or constant. @@ type TYPE; expression THING; identifier COUNT_ID; constant COUNT_CONST; @@ ( - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_ID) + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_ID + COUNT_ID, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (COUNT_CONST) + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * COUNT_CONST + COUNT_CONST, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_ID) + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_ID + COUNT_ID, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (COUNT_CONST) + COUNT_CONST, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * COUNT_CONST + COUNT_CONST, sizeof(THING) , ...) ) // 2-factor product, only identifiers. @@ identifier SIZE, COUNT; @@ - kzalloc + kcalloc ( - SIZE * COUNT + COUNT, SIZE , ...) // 3-factor product with 1 sizeof(type) or sizeof(expression), with // redundant parens removed. @@ expression THING; identifier STRIDE, COUNT; type TYPE; @@ ( kzalloc( - sizeof(TYPE) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(TYPE) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(TYPE)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * (COUNT) * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * (STRIDE) + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) | kzalloc( - sizeof(THING) * COUNT * STRIDE + array3_size(COUNT, STRIDE, sizeof(THING)) , ...) ) // 3-factor product with 2 sizeof(variable), with redundant parens removed. @@ expression THING1, THING2; identifier COUNT; type TYPE1, TYPE2; @@ ( kzalloc( - sizeof(TYPE1) * sizeof(TYPE2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(TYPE2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(THING1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(THING1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * COUNT + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) | kzalloc( - sizeof(TYPE1) * sizeof(THING2) * (COUNT) + array3_size(COUNT, sizeof(TYPE1), sizeof(THING2)) , ...) ) // 3-factor product, only identifiers, with redundant parens removed. @@ identifier STRIDE, SIZE, COUNT; @@ ( kzalloc( - (COUNT) * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * STRIDE * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - (COUNT) * (STRIDE) * (SIZE) + array3_size(COUNT, STRIDE, SIZE) , ...) | kzalloc( - COUNT * STRIDE * SIZE + array3_size(COUNT, STRIDE, SIZE) , ...) ) // Any remaining multi-factor products, first at least 3-factor products, // when they're not all constants... @@ expression E1, E2, E3; constant C1, C2, C3; @@ ( kzalloc(C1 * C2 * C3, ...) | kzalloc( - (E1) * E2 * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * E3 + array3_size(E1, E2, E3) , ...) | kzalloc( - (E1) * (E2) * (E3) + array3_size(E1, E2, E3) , ...) | kzalloc( - E1 * E2 * E3 + array3_size(E1, E2, E3) , ...) ) // And then all remaining 2 factors products when they're not all constants, // keeping sizeof() as the second factor argument. @@ expression THING, E1, E2; type TYPE; constant C1, C2, C3; @@ ( kzalloc(sizeof(THING) * C2, ...) | kzalloc(sizeof(TYPE) * C2, ...) | kzalloc(C1 * C2 * C3, ...) | kzalloc(C1 * C2, ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * (E2) + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(TYPE) * E2 + E2, sizeof(TYPE) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * (E2) + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - sizeof(THING) * E2 + E2, sizeof(THING) , ...) | - kzalloc + kcalloc ( - (E1) * E2 + E1, E2 , ...) | - kzalloc + kcalloc ( - (E1) * (E2) + E1, E2 , ...) | - kzalloc + kcalloc ( - E1 * E2 + E1, E2 , ...) ) Signed-off-by: Kees Cook <keescook@chromium.org>
2018-06-06Merge tag 'audit-pr-20180605' of git://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/auditLinus Torvalds1-6/+6
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://git.kernel.org/pub/scm/linux/kernel/git/pcmoore/audit: 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
2018-05-29selinux: KASAN: slab-out-of-bounds in xattr_getsecuritySachin Grover1-1/+1
Call trace: [<ffffff9203a8d7a8>] dump_backtrace+0x0/0x428 [<ffffff9203a8dbf8>] show_stack+0x28/0x38 [<ffffff920409bfb8>] dump_stack+0xd4/0x124 [<ffffff9203d187e8>] print_address_description+0x68/0x258 [<ffffff9203d18c00>] kasan_report.part.2+0x228/0x2f0 [<ffffff9203d1927c>] kasan_report+0x5c/0x70 [<ffffff9203d1776c>] check_memory_region+0x12c/0x1c0 [<ffffff9203d17cdc>] memcpy+0x34/0x68 [<ffffff9203d75348>] xattr_getsecurity+0xe0/0x160 [<ffffff9203d75490>] vfs_getxattr+0xc8/0x120 [<ffffff9203d75d68>] getxattr+0x100/0x2c8 [<ffffff9203d76fb4>] SyS_fgetxattr+0x64/0xa0 [<ffffff9203a83f70>] el0_svc_naked+0x24/0x28 If user get root access and calls security.selinux setxattr() with an embedded NUL on a file and then if some process performs a getxattr() on that file with a length greater than the actual length of the string, it would result in a panic. To fix this, add the actual length of the string to the security context instead of the length passed by the userspace process. Signed-off-by: Sachin Grover <sgrover@codeaurora.org> Cc: stable@vger.kernel.org Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-05-14audit: use inline function to get audit contextRichard Guy Briggs1-6/+6
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 <rgb@redhat.com> [PM: merge fuzz in auditsc.c and selinuxfs.c, checkpatch.pl fixes] Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-20selinux: wrap AVC stateStephen Smalley1-4/+5
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 <sds@tycho.nsa.gov> Reviewed-by: James Morris <james.morris@microsoft.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-20selinux: fix handling of uninitialized selinux state in get_bools/classesStephen Smalley1-0/+13
If security_get_bools/classes are called before the selinux state is initialized (i.e. before first policy load), then they should just return immediately with no booleans/classes. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-02selinux: rename the {is,set}_enforcing() functionsPaul Moore1-3/+3
Rename is_enforcing() to enforcing_enabled() and enforcing_set() to set_enforcing(). Signed-off-by: Paul Moore <paul@paul-moore.com>
2018-03-01selinux: wrap global selinux stateStephen Smalley1-467/+611
Define a selinux state structure (struct selinux_state) for global SELinux state and pass it explicitly to all security server functions. The public portion of the structure contains state that is used throughout the SELinux code, such as the enforcing mode. The structure also contains a pointer to a selinux_ss structure whose definition is private to the security server and contains security server specific state such as the policy database and SID table. This change should have no effect on SELinux behavior or APIs (userspace or LSM). It merely wraps SELinux state and passes it explicitly as needed. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: minor fixups needed due to collisions with the SCTP patches] Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-12-05selinux: skip bounded transition processing if the policy isn't loadedPaul Moore1-0/+3
We can't do anything reasonable in security_bounded_transition() if we don't have a policy loaded, and in fact we could run into problems with some of the code inside expecting a policy. Fix these problems like we do many others in security/selinux/ss/services.c by checking to see if the policy is loaded (ss_initialized) and returning quickly if it isn't. Reported-by: syzbot <syzkaller-bugs@googlegroups.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: James Morris <james.l.morris@oracle.com>
2017-11-28selinux: ensure the context is NUL terminated in security_context_to_sid_core()Paul Moore1-10/+8
The syzbot/syzkaller automated tests found a problem in security_context_to_sid_core() during early boot (before we load the SELinux policy) where we could potentially feed context strings without NUL terminators into the strcmp() function. We already guard against this during normal operation (after the SELinux policy has been loaded) by making a copy of the context strings and explicitly adding a NUL terminator to the end. The patch extends this protection to the early boot case (no loaded policy) by moving the context copy earlier in security_context_to_sid_core(). Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Paul Moore <paul@paul-moore.com> Reviewed-By: William Roberts <william.c.roberts@intel.com>
2017-09-20selinux: Use kmem_cache for hashtab_nodeKyeongdon Kim1-0/+4
During random test as own device to check slub account, we found some slack memory from hashtab_node(kmalloc-64). By using kzalloc(), middle of test result like below: allocated size 240768 request size 45144 slack size 195624 allocation count 3762 So, we want to use kmem_cache_zalloc() and that can reduce memory size 52byte(slack size/alloc count) per each struct. Signed-off-by: Kyeongdon Kim <kyeongdon.kim@lge.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-08-17selinux: update my email addressStephen Smalley1-1/+1
Update my email address since epoch.ncsc.mil no longer exists. MAINTAINERS and CREDITS are already correct. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-08-02selinux: Generalize support for NNP/nosuid SELinux domain transitionsStephen Smalley1-1/+6
As systemd ramps up enabling NNP (NoNewPrivileges) for system services, it is increasingly breaking SELinux domain transitions for those services and their descendants. systemd enables NNP not only for services whose unit files explicitly specify NoNewPrivileges=yes but also for services whose unit files specify any of the following options in combination with running without CAP_SYS_ADMIN (e.g. specifying User= or a CapabilityBoundingSet= without CAP_SYS_ADMIN): SystemCallFilter=, SystemCallArchitectures=, RestrictAddressFamilies=, RestrictNamespaces=, PrivateDevices=, ProtectKernelTunables=, ProtectKernelModules=, MemoryDenyWriteExecute=, or RestrictRealtime= as per the systemd.exec(5) man page. The end result is bad for the security of both SELinux-disabled and SELinux-enabled systems. Packagers have to turn off these options in the unit files to preserve SELinux domain transitions. For users who choose to disable SELinux, this means that they miss out on at least having the systemd-supported protections. For users who keep SELinux enabled, they may still be missing out on some protections because it isn't necessarily guaranteed that the SELinux policy for that service provides the same protections in all cases. commit 7b0d0b40cd78 ("selinux: Permit bounded transitions under NO_NEW_PRIVS or NOSUID.") allowed bounded transitions under NNP in order to support limited usage for sandboxing programs. However, defining typebounds for all of the affected service domains is impractical to implement in policy, since typebounds requires us to ensure that each domain is allowed everything all of its descendant domains are allowed, and this has to be repeated for the entire chain of domain transitions. There is no way to clone all allow rules from descendants to their ancestors in policy currently, and doing so would be undesirable even if it were practical, as it requires leaking permissions to objects and operations into ancestor domains that could weaken their own security in order to allow them to the descendants (e.g. if a descendant requires execmem permission, then so do all of its ancestors; if a descendant requires execute permission to a file, then so do all of its ancestors; if a descendant requires read to a symbolic link or temporary file, then so do all of its ancestors...). SELinux domains are intentionally not hierarchical / bounded in this manner normally, and making them so would undermine their protections and least privilege. We have long had a similar tension with SELinux transitions and nosuid mounts, albeit not as severe. Users often have had to choose between retaining nosuid on a mount and allowing SELinux domain transitions on files within those mounts. This likewise leads to unfortunate tradeoffs in security. Decouple NNP/nosuid from SELinux transitions, so that we don't have to make a choice between them. Introduce a nnp_nosuid_transition policy capability that enables transitions under NNP/nosuid to be based on a permission (nnp_transition for NNP; nosuid_transition for nosuid) between the old and new contexts in addition to the current support for bounded transitions. Domain transitions can then be allowed in policy without requiring the parent to be a strict superset of all of its children. With this change, systemd unit files can be left unmodified from upstream. SELinux-disabled and SELinux-enabled users will benefit from retaining any of the systemd-provided protections. SELinux policy will only need to be adapted to enable the new policy capability and to allow the new permissions between domain pairs as appropriate. NB: Allowing nnp_transition between two contexts opens up the potential for the old context to subvert the new context by installing seccomp filters before the execve. Allowing nosuid_transition between two contexts opens up the potential for a context transition to occur on a file from an untrusted filesystem (e.g. removable media or remote filesystem). Use with care. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-06-09selinux: use kmem_cache for ebitmapJunil Lee1-0/+4
The allocated size for each ebitmap_node is 192byte by kzalloc(). Then, ebitmap_node size is fixed, so it's possible to use only 144byte for each object by kmem_cache_zalloc(). It can reduce some dynamic allocation size. Signed-off-by: Junil Lee <junil0814.lee@lge.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23selinux: Add IB Port SMP access vectorDaniel Jurgens1-0/+41
Add a type for Infiniband ports and an access vector for subnet management packets. Implement the ib_port_smp hook to check that the caller has permission to send and receive SMPs on the end port specified by the device name and port. Add interface to query the SID for a IB port, which walks the IB_PORT ocontexts to find an entry for the given name and port. Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Acked-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23selinux: Implement Infiniband PKey "Access" access vectorDaniel Jurgens1-0/+40
Add a type and access vector for PKeys. Implement the ib_pkey_access hook to check that the caller has permission to access the PKey on the given subnet prefix. Add an interface to get the PKey SID. Walk the PKey ocontexts to find an entry for the given subnet prefix and pkey. Signed-off-by: Daniel Jurgens <danielj@mellanox.com> Reviewed-by: James Morris <james.l.morris@oracle.com> Acked-by: Doug Ledford <dledford@redhat.com> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-05-23selinux: log policy capability state when a policy is loadedStephen Smalley1-0/+23
Log the state of SELinux policy capabilities when a policy is loaded. For each policy capability known to the kernel, log the policy capability name and the value set in the policy. For policy capabilities that are set in the loaded policy but unknown to the kernel, log the policy capability index, since this is the only information presently available in the policy. Sample output with a policy created with a new capability defined that is not known to the kernel: SELinux: policy capability network_peer_controls=1 SELinux: policy capability open_perms=1 SELinux: policy capability extended_socket_class=1 SELinux: policy capability always_check_network=0 SELinux: policy capability cgroup_seclabel=0 SELinux: unknown policy capability 5 Resolves: https://github.com/SELinuxProject/selinux-kernel/issues/32 Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-29selinux: Remove unnecessary check of array base in selinux_set_mapping()Matthias Kaehlcke1-1/+1
'perms' will never be NULL since it isn't a plain pointer but an array of u32 values. This fixes the following warning when building with clang: security/selinux/ss/services.c:158:16: error: address of array 'p_in->perms' will always evaluate to 'true' [-Werror,-Wpointer-bool-conversion] while (p_in->perms && p_in->perms[k]) { Signed-off-by: Matthias Kaehlcke <mka@chromium.org> Signed-off-by: Paul Moore <paul@paul-moore.com>
2017-03-02selinux: wrap cgroup seclabel support with its own policy capabilityStephen Smalley1-0/+4
commit 1ea0ce40690dff38935538e8dab7b12683ded0d3 ("selinux: allow changing labels for cgroupfs") broke the Android init program, which looks up security contexts whenever creating directories and attempts to assign them via setfscreatecon(). When creating subdirectories in cgroup mounts, this would previously be ignored since cgroup did not support userspace setting of security contexts. However, after the commit, SELinux would attempt to honor the requested context on cgroup directories and fail due to permission denial. Avoid breaking existing userspace/policy by wrapping this change with a conditional on a new cgroup_seclabel policy capability. This preserves existing behavior until/unless a new policy explicitly enables this capability. Reported-by: John Stultz <john.stultz@linaro.org> Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com> Signed-off-by: James Morris <james.l.morris@oracle.com>
2017-01-09selinux: support distinctions among all network address familiesStephen Smalley1-0/+3
Extend SELinux to support distinctions among all network address families implemented by the kernel by defining new socket security classes and mapping to them. Otherwise, many sockets are mapped to the generic socket class and are indistinguishable in policy. This has come up previously with regard to selectively allowing access to bluetooth sockets, and more recently with regard to selectively allowing access to AF_ALG sockets. Guido Trentalancia submitted a patch that took a similar approach to add only support for distinguishing AF_ALG sockets, but this generalizes his approach to handle all address families implemented by the kernel. Socket security classes are also added for ICMP and SCTP sockets. Socket security classes were not defined for AF_* values that are reserved but unimplemented in the kernel, e.g. AF_NETBEUI, AF_SECURITY, AF_ASH, AF_ECONET, AF_SNA, AF_WANPIPE. Backward compatibility is provided by only enabling the finer-grained socket classes if a new policy capability is set in the policy; older policies will behave as before. The legacy redhat1 policy capability that was only ever used in testing within Fedora for ptrace_child is reclaimed for this purpose; as far as I can tell, this policy capability is not enabled in any supported distro policy. Add a pair of conditional compilation guards to detect when new AF_* values are added so that we can update SELinux accordingly rather than having to belatedly update it long after new address families are introduced. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-05-31selinux: Only apply bounds checking to source typesStephen Smalley1-48/+22
The current bounds checking of both source and target types requires allowing any domain that has access to the child domain to also have the same permissions to the parent, which is undesirable. Drop the target bounds checking. KaiGai Kohei originally removed all use of target bounds in commit 7d52a155e38d ("selinux: remove dead code in type_attribute_bounds_av()") but this was reverted in commit 2ae3ba39389b ("selinux: libsepol: remove dead code in check_avtab_hierarchy_callback()") because it would have required explicitly allowing the parent any permissions to the child that the child is allowed to itself. This change in contrast retains the logic for the case where both source and target types are bounded, thereby allowing access if the parent of the source is allowed the corresponding permissions to the parent of the target. Further, this change reworks the logic such that we only perform a single computation for each case and there is no ambiguity as to how to resolve a bounds violation. Under the new logic, if the source type and target types are both bounded, then the parent of the source type must be allowed the same permissions to the parent of the target type. If only the source type is bounded, then the parent of the source type must be allowed the same permissions to the target type. Examples of the new logic and comparisons with the old logic: 1. If we have: typebounds A B; then: allow B self:process <permissions>; will satisfy the bounds constraint iff: allow A self:process <permissions>; is also allowed in policy. Under the old logic, the allow rule on B satisfies the bounds constraint if any of the following three are allowed: allow A B:process <permissions>; or allow B A:process <permissions>; or allow A self:process <permissions>; However, either of the first two ultimately require the third to satisfy the bounds constraint under the old logic, and therefore this degenerates to the same result (but is more efficient - we only need to perform one compute_av call). 2. If we have: typebounds A B; typebounds A_exec B_exec; then: allow B B_exec:file <permissions>; will satisfy the bounds constraint iff: allow A A_exec:file <permissions>; is also allowed in policy. This is essentially the same as #1; it is merely included as an example of dealing with object types related to a bounded domain in a manner that satisfies the bounds relationship. Note that this approach is preferable to leaving B_exec unbounded and having: allow A B_exec:file <permissions>; in policy because that would allow B's entrypoints to be used to enter A. Similarly for _tmp or other related types. 3. If we have: typebounds A B; and an unbounded type T, then: allow B T:file <permissions>; will satisfy the bounds constraint iff: allow A T:file <permissions>; is allowed in policy. The old logic would have been identical for this example. 4. If we have: typebounds A B; and an unbounded domain D, then: allow D B:unix_stream_socket <permissions>; is not subject to any bounds constraints under the new logic because D is not bounded. This is desirable so that we can allow a domain to e.g. connectto a child domain without having to allow it to do the same to its parent. The old logic would have required: allow D A:unix_stream_socket <permissions>; to also be allowed in policy. Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> [PM: re-wrapped description to appease checkpatch.pl] Signed-off-by: Paul Moore <paul@paul-moore.com>
2016-04-14selinux: Change bool variable name to index.Prarit Bhargava1-3/+3
security_get_bool_value(int bool) argument "bool" conflicts with in-kernel macros such as BUILD_BUG(). This patch changes this to index which isn't a type. Cc: Paul Moore <paul@paul-moore.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Cc: Eric Paris <eparis@parisplace.org> Cc: James Morris <james.l.morris@oracle.com> Cc: "Serge E. Hallyn" <serge@hallyn.com> Cc: Rasmus Villemoes <linux@rasmusvillemoes.dk> Cc: Andrew Perepechko <anserper@ya.ru> Cc: Jeff Vander Stoep <jeffv@google.com> Cc: selinux@tycho.nsa.gov Cc: Eric Paris <eparis@redhat.com> Cc: Paul Moore <pmoore@redhat.com> Cc: David Howells <dhowells@redhat.com> Signed-off-by: Prarit Bhargava <prarit@redhat.com> Acked-by: David Howells <dhowells@redhat.com> [PM: wrapped description for checkpatch.pl, use "selinux:..." as subj] Signed-off-by: Paul Moore <paul@paul-moore.com>
2015-12-24selinux: export validatetrans decisionsAndrew Perepechko1-7/+27
Make validatetrans decisions available through selinuxfs. "/validatetrans" is added to selinuxfs for this purpose. This functionality is needed by file system servers implemented in userspace or kernelspace without the VFS layer. Writing "$oldcontext $newcontext $tclass $taskcontext" to /validatetrans is expected to return 0 if the transition is allowed and -EPERM otherwise. Signed-off-by: Andrew Perepechko <anserper@ya.ru> CC: andrew.perepechko@seagate.com Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: Paul Moore <pmoore@redhat.com>