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path: root/security/selinux/avc.c
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2012-04-03lsm_audit: don't specify the audit pre/post callbacks in 'struct ↵Linus Torvalds
common_audit_data' It just bloats the audit data structure for no good reason, since the only time those fields are filled are just before calling the common_lsm_audit() function, which is also the only user of those fields. So just make them be the arguments to common_lsm_audit(), rather than bloating that structure that is passed around everywhere, and is initialized in hot paths. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03SELinux: do not allocate stack space for AVC data unless neededEric Paris
Instead of declaring the entire selinux_audit_data on the stack when we start an operation on declare it on the stack if we are going to use it. We know it's usefulness at the end of the security decision and can declare it there. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03SELinux: remove avd from slow_avc_audit()Eric Paris
We don't use the argument, so remove it. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03LSM: shrink sizeof LSM specific portion of common_audit_dataEric Paris
Linus found that the gigantic size of the common audit data caused a big perf hit on something as simple as running stat() in a loop. This patch requires LSMs to declare the LSM specific portion separately rather than doing it in a union. Thus each LSM can be responsible for shrinking their portion and don't have to pay a penalty just because other LSMs have a bigger space requirement. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-31selinux: inline avc_audit() and avc_has_perm_noaudit() into callerLinus Torvalds
Now that all the slow-path code is gone from these functions, we can inline them into the main caller - avc_has_perm_flags(). Now the compiler can see that 'avc' is allocated on the stack for this case, which helps register pressure a bit. It also actually shrinks the total stack frame, because the stack frame that avc_has_perm_flags() always needed (for that 'avc' allocation) is now sufficient for the inlined functions too. Inlining isn't bad - but mindless inlining of cold code (see the previous commit) is. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-31selinux: don't inline slow-path code into avc_has_perm_noaudit()Linus Torvalds
The selinux AVC paths remain some of the hottest (and deepest) codepaths at filename lookup time, and we make it worse by having the slow path cases take up I$ and stack space even when they don't trigger. Gcc tends to always want to inline functions that are just called once - never mind that this might make for slower and worse code in the caller. So this tries to improve on it a bit by making the slow-path cases explicitly separate functions that are marked noinline, causing gcc to at least no longer allocate stack space for them unless they are actually called. It also seems to help register allocation a tiny bit, since gcc now doesn't take the slow case code into account. Uninlining the slow path may also allow us to inline the remaining hot path into the one caller that actually matters: avc_has_perm_flags(). I'll have to look at that separately, but both avc_audit() and avc_has_perm_noaudit() are now small and lean enough that inlining them may make sense. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-22security: optimize avc_audit() common pathLinus Torvalds
avc_audit() did a lot of jumping around and had a big stack frame, all for the uncommon case. Split up the uncommon case (which we really can't make go fast anyway) into its own slow function, and mark the conditional branches appropriately for the common likely case. This causes avc_audit() to no longer show up as one of the hottest functions on the branch profiles (the new "perf -b" thing), and makes the cycle profiles look really nice and dense too. The whole audit path is still annoyingly very much one of the biggest costs of name lookup, so these things are worth optimizing for. I wish we could just tell people to turn it off, but realistically we do need it: we just need to make sure that the overhead of the necessary evil is as low as possible. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-07-20selinux: don't transliterate MAY_NOT_BLOCK to IPERM_FLAG_RCUAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-26selinux: don't pass in NULL avd to avc_has_perm_noauditLinus Torvalds
Right now security_get_user_sids() will pass in a NULL avd pointer to avc_has_perm_noaudit(), which then forces that function to have a dummy entry for that case and just generally test it. Don't do it. The normal callers all pass a real avd pointer, and this helper function is incredibly hot. So don't make avc_has_perm_noaudit() do conditional stuff that isn't needed for the common case. This also avoids some duplicated stack space. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-24Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into ↵James Morris
for-linus Conflicts: lib/flex_array.c security/selinux/avc.c security/selinux/hooks.c security/selinux/ss/policydb.c security/smack/smack_lsm.c Manually resolve conflicts. Signed-off-by: James Morris <jmorris@namei.org>
2011-05-19selinux: avoid unnecessary avc cache stat hit countLinus Torvalds
There is no point in counting hits - we can calculate it from the number of lookups and misses. This makes the avc statistics a bit smaller, and makes the code generation better too. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-05-19selinux: de-crapify avc cache stat code generationLinus Torvalds
You can turn off the avc cache stats, but distributions seem to not do that (perhaps because several performance tuning how-to's talk about the avc cache statistics). Which is sad, because the code it generates is truly horrendous, with the statistics update being sandwitched between get_cpu/put_cpu which in turn causes preemption disables etc. We're talking ten+ instructions just to increment a per-cpu variable in some pretty hot code. Fix the craziness by just using 'this_cpu_inc()' instead. Suddenly we only need a single 'inc' instruction to increment the statistics. This is quite noticeable in the incredibly hot avc_has_perm_noaudit() function (which triggers all the statistics by virtue of doing an avc_lookup() call). Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-25SELINUX: Make selinux cache VFS RCU walks safeEric Paris
Now that the security modules can decide whether they support the dcache RCU walk or not it's possible to make selinux a bit more RCU friendly. The SELinux AVC and security server access decision code is RCU safe. A specific piece of the LSM audit code may not be RCU safe. This patch makes the VFS RCU walk retry if it would hit the non RCU safe chunk of code. It will normally just work under RCU. This is done simply by passing the VFS RCU state as a flag down into the avc_audit() code and returning ECHILD there if it would have an issue. Based-on-patch-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-25LSM: split LSM_AUDIT_DATA_FS into _PATH and _INODEEric Paris
The lsm common audit code has wacky contortions making sure which pieces of information are set based on if it was given a path, dentry, or inode. Split this into path and inode to get rid of some of the code complexity. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2011-04-25SELINUX: Make selinux cache VFS RCU walks safeEric Paris
Now that the security modules can decide whether they support the dcache RCU walk or not it's possible to make selinux a bit more RCU friendly. The SELinux AVC and security server access decision code is RCU safe. A specific piece of the LSM audit code may not be RCU safe. This patch makes the VFS RCU walk retry if it would hit the non RCU safe chunk of code. It will normally just work under RCU. This is done simply by passing the VFS RCU state as a flag down into the avc_audit() code and returning ECHILD there if it would have an issue. Based-on-patch-by: Andi Kleen <ak@linux.intel.com> Signed-off-by: Eric Paris <eparis@redhat.com>
2010-08-02SELinux: special dontaudit for access checksEric Paris
Currently there are a number of applications (nautilus being the main one) which calls access() on files in order to determine how they should be displayed. It is normal and expected that nautilus will want to see if files are executable or if they are really read/write-able. access() should return the real permission. SELinux policy checks are done in access() and can result in lots of AVC denials as policy denies RWX on files which DAC allows. Currently SELinux must dontaudit actual attempts to read/write/execute a file in order to silence these messages (and not flood the logs.) But dontaudit rules like that can hide real attacks. This patch addes a new common file permission audit_access. This permission is special in that it is meaningless and should never show up in an allow rule. Instead the only place this permission has meaning is in a dontaudit rule like so: dontaudit nautilus_t sbin_t:file audit_access With such a rule if nautilus just checks access() we will still get denied and thus userspace will still get the correct answer but we will not log the denial. If nautilus attempted to actually perform one of the forbidden actions (rather than just querying access(2) about it) we would still log a denial. This type of dontaudit rule should be used sparingly, as it could be a method for an attacker to probe the system permissions without detection. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02selinux: remove all rcu head initializationsPaul E. McKenney
Remove all rcu head inits. We don't care about the RCU head state before passing it to call_rcu() anyway. Only leave the "on_stack" variants so debugobjects can keep track of objects on stack. Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Stephen Smalley <sds@tycho.nsa.gov> Reviewed-by: James Morris <jmorris@namei.org> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: James Morris <jmorris@namei.org>
2010-04-28LSM Audit: rename LSM_AUDIT_NO_AUDIT to LSM_AUDIT_DATA_NONEEric Paris
Most of the LSM common audit work uses LSM_AUDIT_DATA_* for the naming. This was not so for LSM_AUDIT_NO_AUDIT which means the generic initializer cannot be used. This patch just renames the flag so the generic initializer can be used. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2010-03-08Merge branch 'for-next' into for-linusJiri Kosina
Conflicts: Documentation/filesystems/proc.txt arch/arm/mach-u300/include/mach/debug-macro.S drivers/net/qlge/qlge_ethtool.c drivers/net/qlge/qlge_main.c drivers/net/typhoon.c
2010-02-05fix comment typos in avc.cJustin P. Mattock
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-02-03selinux: Only audit permissions specified in policyStephen Smalley
Only audit the permissions specified by the policy rules. Before: type=AVC msg=audit(01/28/2010 14:30:46.690:3250) : avc: denied { read append } for pid=14092 comm=foo name=test_file dev=dm-1 ino=132932 scontext=unconfined_u:unconfined_r:load_policy_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:rpm_tmp_t:s0 tclass=file After: type=AVC msg=audit(01/28/2010 14:52:37.448:26) : avc: denied { append } for pid=1917 comm=foo name=test_file dev=dm-1 ino=132932 scontext=unconfined_u:unconfined_r:load_policy_t:s0-s0:c0.c1023 tcontext=unconfined_u:object_r:rpm_tmp_t:s0 tclass=file Reference: https://bugzilla.redhat.com/show_bug.cgi?id=558499 Reported-by: Tom London <selinux@gmail.com> Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2010-01-18selinux: change the handling of unknown classesStephen Smalley
If allow_unknown==deny, SELinux treats an undefined kernel security class as an error condition rather than as a typical permission denial and thus does not allow permissions on undefined classes even when in permissive mode. Change the SELinux logic so that this case is handled as a typical permission denial, subject to the usual permissive mode and permissive domain handling. Also drop the 'requested' argument from security_compute_av() and helpers as it is a legacy of the original security server interface and is unused. Changes: - Handle permissive domains consistently by moving up the test for a permissive domain. - Make security_compute_av_user() consistent with security_compute_av(); the only difference now is that security_compute_av() performs mapping between the kernel-private class and permission indices and the policy values. In the userspace case, this mapping is handled by libselinux. - Moved avd_init inside the policy lock. Based in part on a patch by Paul Moore <paul.moore@hp.com>. Reported-by: Andrew Worsley <amworsley@gmail.com> Signed-off-by: Stephen D. Smalley <sds@tycho.nsa.gov> Reviewed-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-11-24SELinux: print denials for buggy kernel with unknown permsEric Paris
Historically we've seen cases where permissions are requested for classes where they do not exist. In particular we have seen CIFS forget to set i_mode to indicate it is a directory so when we later check something like remove_name we have problems since it wasn't defined in tclass file. This used to result in a avc which included the permission 0x2000 or something. Currently the kernel will deny the operations (good thing) but will not print ANY information (bad thing). First the auditdeny field is no extended to include unknown permissions. After that is fixed the logic in avc_dump_query to output this information isn't right since it will remove the permission from the av and print the phrase "<NULL>". This takes us back to the behavior before the classmap rewrite. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-10-07selinux: dynamic class/perm discoveryStephen Smalley
Modify SELinux to dynamically discover class and permission values upon policy load, based on the dynamic object class/perm discovery logic from libselinux. A mapping is created between kernel-private class and permission indices used outside the security server and the policy values used within the security server. The mappings are only applied upon kernel-internal computations; similar mappings for the private indices of userspace object managers is handled on a per-object manager basis by the userspace AVC. The interfaces for compute_av and transition_sid are split for kernel vs. userspace; the userspace functions are distinguished by a _user suffix. The kernel-private class indices are no longer tied to the policy values and thus do not need to skip indices for userspace classes; thus the kernel class index values are compressed. The flask.h definitions were regenerated by deleting the userspace classes from refpolicy's definitions and then regenerating the headers. Going forward, we can just maintain the flask.h, av_permissions.h, and classmap.h definitions separately from policy as they are no longer tied to the policy values. The next patch introduces a utility to automate generation of flask.h and av_permissions.h from the classmap.h definitions. The older kernel class and permission string tables are removed and replaced by a single security class mapping table that is walked at policy load to generate the mapping. The old kernel class validation logic is completely replaced by the mapping logic. The handle unknown logic is reworked. reject_unknown=1 is handled when the mappings are computed at policy load time, similar to the old handling by the class validation logic. allow_unknown=1 is handled when computing and mapping decisions - if the permission was not able to be mapped (i.e. undefined, mapped to zero), then it is automatically added to the allowed vector. If the class was not able to be mapped (i.e. undefined, mapped to zero), then all permissions are allowed for it if allow_unknown=1. avc_audit leverages the new security class mapping table to lookup the class and permission names from the kernel-private indices. The mdp program is updated to use the new table when generating the class definitions and allow rules for a minimal boot policy for the kernel. It should be noted that this policy will not include any userspace classes, nor will its policy index values for the kernel classes correspond with the ones in refpolicy (they will instead match the kernel-private indices). Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-23SELinux: do not destroy the avc_cache_nodepEric Paris
The security_ops reset done when SELinux is disabled at run time is done after the avc cache is freed and after the kmem_cache for the avc is also freed. This means that between the time the selinux disable code destroys the avc_node_cachep another process could make a security request and could try to allocate from the cache. We are just going to leave the cachep around, like we always have. SELinux: Disabled at runtime. BUG: unable to handle kernel NULL pointer dereference at (null) IP: [<ffffffff81122537>] kmem_cache_alloc+0x9a/0x185 PGD 0 Oops: 0000 [#1] PREEMPT SMP DEBUG_PAGEALLOC last sysfs file: CPU 1 Modules linked in: Pid: 12, comm: khelper Not tainted 2.6.31-tip-05525-g0eeacc6-dirty #14819 System Product Name RIP: 0010:[<ffffffff81122537>] [<ffffffff81122537>] kmem_cache_alloc+0x9a/0x185 RSP: 0018:ffff88003f9258b0 EFLAGS: 00010086 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000078c0129e RDX: 0000000000000000 RSI: ffffffff8130b626 RDI: ffffffff81122528 RBP: ffff88003f925900 R08: 0000000078c0129e R09: 0000000000000001 R10: 0000000000000000 R11: 0000000078c0129e R12: 0000000000000246 R13: 0000000000008020 R14: ffff88003f8586d8 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff880002b00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0018 ES: 0018 CR0: 000000008005003b CR2: 0000000000000000 CR3: 0000000001001000 CR4: 00000000000006e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: ffffffff827bd420 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Process khelper (pid: 12, threadinfo ffff88003f924000, task ffff88003f928000) Stack: 0000000000000246 0000802000000246 ffffffff8130b626 0000000000000001 <0> 0000000078c0129e 0000000000000000 ffff88003f925a70 0000000000000002 <0> 0000000000000001 0000000000000001 ffff88003f925960 ffffffff8130b626 Call Trace: [<ffffffff8130b626>] ? avc_alloc_node+0x36/0x273 [<ffffffff8130b626>] avc_alloc_node+0x36/0x273 [<ffffffff8130b545>] ? avc_latest_notif_update+0x7d/0x9e [<ffffffff8130b8b4>] avc_insert+0x51/0x18d [<ffffffff8130bcce>] avc_has_perm_noaudit+0x9d/0x128 [<ffffffff8130bf20>] avc_has_perm+0x45/0x88 [<ffffffff8130f99d>] current_has_perm+0x52/0x6d [<ffffffff8130fbb2>] selinux_task_create+0x2f/0x45 [<ffffffff81303bf7>] security_task_create+0x29/0x3f [<ffffffff8105c6ba>] copy_process+0x82/0xdf0 [<ffffffff81091578>] ? register_lock_class+0x2f/0x36c [<ffffffff81091a13>] ? mark_lock+0x2e/0x1e1 [<ffffffff8105d596>] do_fork+0x16e/0x382 [<ffffffff81091578>] ? register_lock_class+0x2f/0x36c [<ffffffff810d9166>] ? probe_workqueue_execution+0x57/0xf9 [<ffffffff81091a13>] ? mark_lock+0x2e/0x1e1 [<ffffffff810d9166>] ? probe_workqueue_execution+0x57/0xf9 [<ffffffff8100cdb2>] kernel_thread+0x82/0xe0 [<ffffffff81078b1f>] ? ____call_usermodehelper+0x0/0x139 [<ffffffff8100ce10>] ? child_rip+0x0/0x20 [<ffffffff81078aea>] ? __call_usermodehelper+0x65/0x9a [<ffffffff8107a5c7>] run_workqueue+0x171/0x27e [<ffffffff8107a573>] ? run_workqueue+0x11d/0x27e [<ffffffff81078a85>] ? __call_usermodehelper+0x0/0x9a [<ffffffff8107a7bc>] worker_thread+0xe8/0x10f [<ffffffff810808e2>] ? autoremove_wake_function+0x0/0x63 [<ffffffff8107a6d4>] ? worker_thread+0x0/0x10f [<ffffffff8108042e>] kthread+0x91/0x99 [<ffffffff8100ce1a>] child_rip+0xa/0x20 [<ffffffff8100c754>] ? restore_args+0x0/0x30 [<ffffffff8108039d>] ? kthread+0x0/0x99 [<ffffffff8100ce10>] ? child_rip+0x0/0x20 Code: 0f 85 99 00 00 00 9c 58 66 66 90 66 90 49 89 c4 fa 66 66 90 66 66 90 e8 83 34 fb ff e8 d7 e9 26 00 48 98 49 8b 94 c6 10 01 00 00 <48> 8b 1a 44 8b 7a 18 48 85 db 74 0f 8b 42 14 48 8b 04 c3 ff 42 RIP [<ffffffff81122537>] kmem_cache_alloc+0x9a/0x185 RSP <ffff88003f9258b0> CR2: 0000000000000000 ---[ end trace 42f41a982344e606 ]--- Reported-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-14SELinux: flush the avc before disabling SELinuxEric Paris
Before SELinux is disabled at boot it can create AVC entries. This patch will flush those entries before disabling SELinux. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-09-14SELinux: seperate avc_cache flushingEric Paris
Move the avc_cache flushing into it's own function so it can be reused when disabling SELinux. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-08-17SELinux: Convert avc_audit to use lsm_audit.hThomas Liu
Convert avc_audit in security/selinux/avc.c to use lsm_audit.h, for better maintainability. - changed selinux to use common_audit_data instead of avc_audit_data - eliminated code in avc.c and used code from lsm_audit.h instead. Had to add a LSM_AUDIT_NO_AUDIT to lsm_audit.h so that avc_audit can call common_lsm_audit and do the pre and post callbacks without doing the actual dump. This makes it so that the patched version behaves the same way as the unpatched version. Also added a denied field to the selinux_audit_data private space, once again to make it so that the patched version behaves like the unpatched. I've tested and confirmed that AVCs look the same before and after this patch. Signed-off-by: Thomas Liu <tliu@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-07-13Revert "SELinux: Convert avc_audit to use lsm_audit.h"James Morris
This reverts commit 8113a8d80f4c6a3dc3724b39b470f3fee9c426b6. The patch causes a stack overflow on my system during boot. Signed-off-by: James Morris <jmorris@namei.org>
2009-07-13SELinux: Convert avc_audit to use lsm_audit.hThomas Liu
Convert avc_audit in security/selinux/avc.c to use lsm_audit.h, for better maintainability and for less code duplication. - changed selinux to use common_audit_data instead of avc_audit_data - eliminated code in avc.c and used code from lsm_audit.h instead. I have tested to make sure that the avcs look the same before and after this patch. Signed-off-by: Thomas Liu <tliu@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-06-25selinux: clean up avc node cache when disabling selinuxThomas Liu
Added a call to free the avc_node_cache when inside selinux_disable because it should not waste resources allocated during avc_init if SELinux is disabled and the cache will never be used. Signed-off-by: Thomas Liu <tliu@redhat.com> Acked-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-06-19Merge branch 'master' into nextJames Morris
2009-06-19Add audit messages on type boundary violationsKaiGai Kohei
The attached patch adds support to generate audit messages on two cases. The first one is a case when a multi-thread process tries to switch its performing security context using setcon(3), but new security context is not bounded by the old one. type=SELINUX_ERR msg=audit(1245311998.599:17): \ op=security_bounded_transition result=denied \ oldcontext=system_u:system_r:httpd_t:s0 \ newcontext=system_u:system_r:guest_webapp_t:s0 The other one is a case when security_compute_av() masked any permissions due to the type boundary violation. type=SELINUX_ERR msg=audit(1245312836.035:32): \ op=security_compute_av reason=bounds \ scontext=system_u:object_r:user_webapp_t:s0 \ tcontext=system_u:object_r:shadow_t:s0:c0 \ tclass=file perms=getattr,open Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-04-02Permissive domain in userspace object managerKaiGai Kohei
This patch enables applications to handle permissive domain correctly. Since the v2.6.26 kernel, SELinux has supported an idea of permissive domain which allows certain processes to work as if permissive mode, even if the global setting is enforcing mode. However, we don't have an application program interface to inform what domains are permissive one, and what domains are not. It means applications focuses on SELinux (XACE/SELinux, SE-PostgreSQL and so on) cannot handle permissive domain correctly. This patch add the sixth field (flags) on the reply of the /selinux/access interface which is used to make an access control decision from userspace. If the first bit of the flags field is positive, it means the required access control decision is on permissive domain, so application should allow any required actions, as the kernel doing. This patch also has a side benefit. The av_decision.flags is set at context_struct_compute_av(). It enables to check required permissions without read_lock(&policy_rwlock). Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Acked-by: Eric Paris <eparis@redhat.com> -- security/selinux/avc.c | 2 +- security/selinux/include/security.h | 4 +++- security/selinux/selinuxfs.c | 4 ++-- security/selinux/ss/services.c | 30 +++++------------------------- 4 files changed, 11 insertions(+), 29 deletions(-) Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14SELinux: convert the avc cache hash list to an hlistEric Paris
We do not need O(1) access to the tail of the avc cache lists and so we are wasting lots of space using struct list_head instead of struct hlist_head. This patch converts the avc cache to use hlists in which there is a single pointer from the head which saves us about 4k of global memory. Resulted in about a 1.5% decrease in time spent in avc_has_perm_noaudit based on oprofile sampling of tbench. Although likely within the noise.... Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed-by: Paul Moore <paul.moore@hp.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14SELinux: code readability with avc_cacheEric Paris
The code making use of struct avc_cache was not easy to read thanks to liberal use of &avc_cache.{slots_lock,slots}[hvalue] throughout. This patch simply creates local pointers and uses those instead of the long global names. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14SELinux: remove unused av.decided fieldEric Paris
It appears there was an intention to have the security server only decide certain permissions and leave other for later as some sort of a portential performance win. We are currently always deciding all 32 bits of permissions and this is a useless couple of branches and wasted space. This patch completely drops the av.decided concept. This in a 17% reduction in the time spent in avc_has_perm_noaudit based on oprofile sampling of a tbench benchmark. Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed-by: Paul Moore <paul.moore@hp.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14SELinux: more careful use of avd in avc_has_perm_noauditEric Paris
we are often needlessly jumping through hoops when it comes to avd entries in avc_has_perm_noaudit and we have extra initialization and memcpy which are just wasting performance. Try to clean the function up a bit. This patch resulted in a 13% drop in time spent in avc_has_perm_noaudit in my oprofile sampling of a tbench benchmark. Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed-by: Paul Moore <paul.moore@hp.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14SELinux: remove the unused ae.usedEric Paris
Currently SELinux code has an atomic which was intended to track how many times an avc entry was used and to evict entries when they haven't been used recently. Instead we never let this atomic get above 1 and evict when it is first checked for eviction since it hits zero. This is a total waste of time so I'm completely dropping ae.used. This change resulted in about a 3% faster avc_has_perm_noaudit when running oprofile against a tbench benchmark. Signed-off-by: Eric Paris <eparis@redhat.com> Reviewed by: Paul Moore <paul.moore@hp.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-02-14SELinux: check seqno when updating an avc_nodeEric Paris
The avc update node callbacks do not check the seqno of the caller with the seqno of the node found. It is possible that a policy change could happen (although almost impossibly unlikely) in which a permissive or permissive_domain decision is not valid for the entry found. Simply pass and check that the seqno of the caller and the seqno of the node found match. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2009-01-05SELinux: shrink sizeof av_inhert selinux_class_perm and contextEric Paris
I started playing with pahole today and decided to put it against the selinux structures. Found we could save a little bit of space on x86_64 (and no harm on i686) just reorganizing some structs. Object size changes: av_inherit: 24 -> 16 selinux_class_perm: 48 -> 40 context: 80 -> 72 Admittedly there aren't many of av_inherit or selinux_class_perm's in the kernel (33 and 1 respectively) But the change to the size of struct context reverberate out a bit. I can get some hard number if they are needed, but I don't see why they would be. We do change which cacheline context->len and context->str would be on, but I don't see that as a problem since we are clearly going to have to load both if the context is to be of any value. I've run with the patch and don't seem to be having any problems. An example of what's going on using struct av_inherit would be: form: to: struct av_inherit { struct av_inherit { u16 tclass; const char **common_pts; const char **common_pts; u32 common_base; u32 common_base; u16 tclass; }; (notice all I did was move u16 tclass to the end of the struct instead of the beginning) Memory layout before the change: struct av_inherit { u16 tclass; /* 2 */ /* 6 bytes hole */ const char** common_pts; /* 8 */ u32 common_base; /* 4 */ /* 4 byes padding */ /* size: 24, cachelines: 1 */ /* sum members: 14, holes: 1, sum holes: 6 */ /* padding: 4 */ }; Memory layout after the change: struct av_inherit { const char ** common_pts; /* 8 */ u32 common_base; /* 4 */ u16 tclass; /* 2 */ /* 2 bytes padding */ /* size: 16, cachelines: 1 */ /* sum members: 14, holes: 0, sum holes: 0 */ /* padding: 2 */ }; Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-10-31misc: replace NIPQUAD()Harvey Harrison
Using NIPQUAD() with NIPQUAD_FMT, %d.%d.%d.%d or %u.%u.%u.%u can be replaced with %pI4 Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-29net: replace %p6 with %pI6Harvey Harrison
Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28misc: replace NIP6_FMT with %p6 format specifierHarvey Harrison
The iscsi_ibft.c changes are almost certainly a bugfix as the pointer 'ip' is a u8 *, so they never print the last 8 bytes of the IPv6 address, and the eight bytes they do print have a zero byte with them in each 16-bit word. Other than that, this should cause no difference in functionality. Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2008-08-29SELinux: add boundary support and thread context assignmentKaiGai Kohei
The purpose of this patch is to assign per-thread security context under a constraint. It enables multi-threaded server application to kick a request handler with its fair security context, and helps some of userspace object managers to handle user's request. When we assign a per-thread security context, it must not have wider permissions than the original one. Because a multi-threaded process shares a single local memory, an arbitary per-thread security context also means another thread can easily refer violated information. The constraint on a per-thread security context requires a new domain has to be equal or weaker than its original one, when it tries to assign a per-thread security context. Bounds relationship between two types is a way to ensure a domain can never have wider permission than its bounds. We can define it in two explicit or implicit ways. The first way is using new TYPEBOUNDS statement. It enables to define a boundary of types explicitly. The other one expand the concept of existing named based hierarchy. If we defines a type with "." separated name like "httpd_t.php", toolchain implicitly set its bounds on "httpd_t". This feature requires a new policy version. The 24th version (POLICYDB_VERSION_BOUNDARY) enables to ship them into kernel space, and the following patch enables to handle it. Signed-off-by: KaiGai Kohei <kaigai@ak.jp.nec.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>
2008-04-28Audit: standardize string audit interfacesEric Paris
This patch standardized the string auditing interfaces. No userspace changes will be visible and this is all just cleanup and consistancy work. We have the following string audit interfaces to use: void audit_log_n_hex(struct audit_buffer *ab, const unsigned char *buf, size_t len); void audit_log_n_string(struct audit_buffer *ab, const char *buf, size_t n); void audit_log_string(struct audit_buffer *ab, const char *buf); void audit_log_n_untrustedstring(struct audit_buffer *ab, const char *string, size_t n); void audit_log_untrustedstring(struct audit_buffer *ab, const char *string); This may be the first step to possibly fixing some of the issues that people have with the string output from the kernel audit system. But we still don't have an agreed upon solution to that problem. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-22SELinux fixups needed for preemptable RCU from -rtPaul E. McKenney
The attached patch needs to move from -rt to mainline given preemptable RCU. This patch fixes SELinux code that implicitly assumes that disabling preemption prevents an RCU grace period from completing, an assumption that is valid for Classic RCU, but not necessarily for preemptable RCU. Explicit rcu_read_lock() calls are thus added. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Acked-by: Steven Rostedt <srostedt@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-04-21SELinux: one little, two little, three little whitespaces, the avc.c saga.Eric Paris
avc.c was bad. It had whitespace and syntax issues which are against our coding style. I have had a little chat with it and the result of that conversation looked like this patch. Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-04-21SELinux: clean up printksEric Paris
Make sure all printk start with KERN_* Make sure all printk end with \n Make sure all printk have the word 'selinux' in them Change "function name" to "%s", __func__ (found 2 wrong) Signed-off-by: Eric Paris <eparis@redhat.com> Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18selinux: introduce permissive typesEric Paris
Introduce the concept of a permissive type. A new ebitmap is introduced to the policy database which indicates if a given type has the permissive bit set or not. This bit is tested for the scontext of any denial. The bit is meaningless on types which only appear as the target of a decision and never the source. A domain running with a permissive type will be allowed to perform any action similarly to when the system is globally set permissive. Signed-off-by: Eric Paris <eparis@redhat.com> Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Signed-off-by: James Morris <jmorris@namei.org>