Commit graph

284 commits

Author SHA1 Message Date
David Howells
3a3b7ce933 CRED: Allow kernel services to override LSM settings for task actions
Allow kernel services to override LSM settings appropriate to the actions
performed by a task by duplicating a set of credentials, modifying it and then
using task_struct::cred to point to it when performing operations on behalf of
a task.

This is used, for example, by CacheFiles which has to transparently access the
cache on behalf of a process that thinks it is doing, say, NFS accesses with a
potentially inappropriate (with respect to accessing the cache) set of
credentials.

This patch provides two LSM hooks for modifying a task security record:

 (*) security_kernel_act_as() which allows modification of the security datum
     with which a task acts on other objects (most notably files).

 (*) security_kernel_create_files_as() which allows modification of the
     security datum that is used to initialise the security data on a file that
     a task creates.

The patch also provides four new credentials handling functions, which wrap the
LSM functions:

 (1) prepare_kernel_cred()

     Prepare a set of credentials for a kernel service to use, based either on
     a daemon's credentials or on init_cred.  All the keyrings are cleared.

 (2) set_security_override()

     Set the LSM security ID in a set of credentials to a specific security
     context, assuming permission from the LSM policy.

 (3) set_security_override_from_ctx()

     As (2), but takes the security context as a string.

 (4) set_create_files_as()

     Set the file creation LSM security ID in a set of credentials to be the
     same as that on a particular inode.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> [Smack changes]
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:28 +11:00
David Howells
3b11a1dece CRED: Differentiate objective and effective subjective credentials on a task
Differentiate the objective and real subjective credentials from the effective
subjective credentials on a task by introducing a second credentials pointer
into the task_struct.

task_struct::real_cred then refers to the objective and apparent real
subjective credentials of a task, as perceived by the other tasks in the
system.

task_struct::cred then refers to the effective subjective credentials of a
task, as used by that task when it's actually running.  These are not visible
to the other tasks in the system.

__task_cred(task) then refers to the objective/real credentials of the task in
question.

current_cred() refers to the effective subjective credentials of the current
task.

prepare_creds() uses the objective creds as a base and commit_creds() changes
both pointers in the task_struct (indeed commit_creds() requires them to be the
same).

override_creds() and revert_creds() change the subjective creds pointer only,
and the former returns the old subjective creds.  These are used by NFSD,
faccessat() and do_coredump(), and will by used by CacheFiles.

In SELinux, current_has_perm() is provided as an alternative to
task_has_perm().  This uses the effective subjective context of current,
whereas task_has_perm() uses the objective/real context of the subject.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:26 +11:00
David Howells
a6f76f23d2 CRED: Make execve() take advantage of copy-on-write credentials
Make execve() take advantage of copy-on-write credentials, allowing it to set
up the credentials in advance, and then commit the whole lot after the point
of no return.

This patch and the preceding patches have been tested with the LTP SELinux
testsuite.

This patch makes several logical sets of alteration:

 (1) execve().

     The credential bits from struct linux_binprm are, for the most part,
     replaced with a single credentials pointer (bprm->cred).  This means that
     all the creds can be calculated in advance and then applied at the point
     of no return with no possibility of failure.

     I would like to replace bprm->cap_effective with:

	cap_isclear(bprm->cap_effective)

     but this seems impossible due to special behaviour for processes of pid 1
     (they always retain their parent's capability masks where normally they'd
     be changed - see cap_bprm_set_creds()).

     The following sequence of events now happens:

     (a) At the start of do_execve, the current task's cred_exec_mutex is
     	 locked to prevent PTRACE_ATTACH from obsoleting the calculation of
     	 creds that we make.

     (a) prepare_exec_creds() is then called to make a copy of the current
     	 task's credentials and prepare it.  This copy is then assigned to
     	 bprm->cred.

  	 This renders security_bprm_alloc() and security_bprm_free()
     	 unnecessary, and so they've been removed.

     (b) The determination of unsafe execution is now performed immediately
     	 after (a) rather than later on in the code.  The result is stored in
     	 bprm->unsafe for future reference.

     (c) prepare_binprm() is called, possibly multiple times.

     	 (i) This applies the result of set[ug]id binaries to the new creds
     	     attached to bprm->cred.  Personality bit clearance is recorded,
     	     but now deferred on the basis that the exec procedure may yet
     	     fail.

         (ii) This then calls the new security_bprm_set_creds().  This should
	     calculate the new LSM and capability credentials into *bprm->cred.

	     This folds together security_bprm_set() and parts of
	     security_bprm_apply_creds() (these two have been removed).
	     Anything that might fail must be done at this point.

         (iii) bprm->cred_prepared is set to 1.

	     bprm->cred_prepared is 0 on the first pass of the security
	     calculations, and 1 on all subsequent passes.  This allows SELinux
	     in (ii) to base its calculations only on the initial script and
	     not on the interpreter.

     (d) flush_old_exec() is called to commit the task to execution.  This
     	 performs the following steps with regard to credentials:

	 (i) Clear pdeath_signal and set dumpable on certain circumstances that
	     may not be covered by commit_creds().

         (ii) Clear any bits in current->personality that were deferred from
             (c.i).

     (e) install_exec_creds() [compute_creds() as was] is called to install the
     	 new credentials.  This performs the following steps with regard to
     	 credentials:

         (i) Calls security_bprm_committing_creds() to apply any security
             requirements, such as flushing unauthorised files in SELinux, that
             must be done before the credentials are changed.

	     This is made up of bits of security_bprm_apply_creds() and
	     security_bprm_post_apply_creds(), both of which have been removed.
	     This function is not allowed to fail; anything that might fail
	     must have been done in (c.ii).

         (ii) Calls commit_creds() to apply the new credentials in a single
             assignment (more or less).  Possibly pdeath_signal and dumpable
             should be part of struct creds.

	 (iii) Unlocks the task's cred_replace_mutex, thus allowing
	     PTRACE_ATTACH to take place.

         (iv) Clears The bprm->cred pointer as the credentials it was holding
             are now immutable.

         (v) Calls security_bprm_committed_creds() to apply any security
             alterations that must be done after the creds have been changed.
             SELinux uses this to flush signals and signal handlers.

     (f) If an error occurs before (d.i), bprm_free() will call abort_creds()
     	 to destroy the proposed new credentials and will then unlock
     	 cred_replace_mutex.  No changes to the credentials will have been
     	 made.

 (2) LSM interface.

     A number of functions have been changed, added or removed:

     (*) security_bprm_alloc(), ->bprm_alloc_security()
     (*) security_bprm_free(), ->bprm_free_security()

     	 Removed in favour of preparing new credentials and modifying those.

     (*) security_bprm_apply_creds(), ->bprm_apply_creds()
     (*) security_bprm_post_apply_creds(), ->bprm_post_apply_creds()

     	 Removed; split between security_bprm_set_creds(),
     	 security_bprm_committing_creds() and security_bprm_committed_creds().

     (*) security_bprm_set(), ->bprm_set_security()

     	 Removed; folded into security_bprm_set_creds().

     (*) security_bprm_set_creds(), ->bprm_set_creds()

     	 New.  The new credentials in bprm->creds should be checked and set up
     	 as appropriate.  bprm->cred_prepared is 0 on the first call, 1 on the
     	 second and subsequent calls.

     (*) security_bprm_committing_creds(), ->bprm_committing_creds()
     (*) security_bprm_committed_creds(), ->bprm_committed_creds()

     	 New.  Apply the security effects of the new credentials.  This
     	 includes closing unauthorised files in SELinux.  This function may not
     	 fail.  When the former is called, the creds haven't yet been applied
     	 to the process; when the latter is called, they have.

 	 The former may access bprm->cred, the latter may not.

 (3) SELinux.

     SELinux has a number of changes, in addition to those to support the LSM
     interface changes mentioned above:

     (a) The bprm_security_struct struct has been removed in favour of using
     	 the credentials-under-construction approach.

     (c) flush_unauthorized_files() now takes a cred pointer and passes it on
     	 to inode_has_perm(), file_has_perm() and dentry_open().

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:24 +11:00
David Howells
d84f4f992c CRED: Inaugurate COW credentials
Inaugurate copy-on-write credentials management.  This uses RCU to manage the
credentials pointer in the task_struct with respect to accesses by other tasks.
A process may only modify its own credentials, and so does not need locking to
access or modify its own credentials.

A mutex (cred_replace_mutex) is added to the task_struct to control the effect
of PTRACE_ATTACHED on credential calculations, particularly with respect to
execve().

With this patch, the contents of an active credentials struct may not be
changed directly; rather a new set of credentials must be prepared, modified
and committed using something like the following sequence of events:

	struct cred *new = prepare_creds();
	int ret = blah(new);
	if (ret < 0) {
		abort_creds(new);
		return ret;
	}
	return commit_creds(new);

There are some exceptions to this rule: the keyrings pointed to by the active
credentials may be instantiated - keyrings violate the COW rule as managing
COW keyrings is tricky, given that it is possible for a task to directly alter
the keys in a keyring in use by another task.

To help enforce this, various pointers to sets of credentials, such as those in
the task_struct, are declared const.  The purpose of this is compile-time
discouragement of altering credentials through those pointers.  Once a set of
credentials has been made public through one of these pointers, it may not be
modified, except under special circumstances:

  (1) Its reference count may incremented and decremented.

  (2) The keyrings to which it points may be modified, but not replaced.

The only safe way to modify anything else is to create a replacement and commit
using the functions described in Documentation/credentials.txt (which will be
added by a later patch).

This patch and the preceding patches have been tested with the LTP SELinux
testsuite.

This patch makes several logical sets of alteration:

 (1) execve().

     This now prepares and commits credentials in various places in the
     security code rather than altering the current creds directly.

 (2) Temporary credential overrides.

     do_coredump() and sys_faccessat() now prepare their own credentials and
     temporarily override the ones currently on the acting thread, whilst
     preventing interference from other threads by holding cred_replace_mutex
     on the thread being dumped.

     This will be replaced in a future patch by something that hands down the
     credentials directly to the functions being called, rather than altering
     the task's objective credentials.

 (3) LSM interface.

     A number of functions have been changed, added or removed:

     (*) security_capset_check(), ->capset_check()
     (*) security_capset_set(), ->capset_set()

     	 Removed in favour of security_capset().

     (*) security_capset(), ->capset()

     	 New.  This is passed a pointer to the new creds, a pointer to the old
     	 creds and the proposed capability sets.  It should fill in the new
     	 creds or return an error.  All pointers, barring the pointer to the
     	 new creds, are now const.

     (*) security_bprm_apply_creds(), ->bprm_apply_creds()

     	 Changed; now returns a value, which will cause the process to be
     	 killed if it's an error.

     (*) security_task_alloc(), ->task_alloc_security()

     	 Removed in favour of security_prepare_creds().

     (*) security_cred_free(), ->cred_free()

     	 New.  Free security data attached to cred->security.

     (*) security_prepare_creds(), ->cred_prepare()

     	 New. Duplicate any security data attached to cred->security.

     (*) security_commit_creds(), ->cred_commit()

     	 New. Apply any security effects for the upcoming installation of new
     	 security by commit_creds().

     (*) security_task_post_setuid(), ->task_post_setuid()

     	 Removed in favour of security_task_fix_setuid().

     (*) security_task_fix_setuid(), ->task_fix_setuid()

     	 Fix up the proposed new credentials for setuid().  This is used by
     	 cap_set_fix_setuid() to implicitly adjust capabilities in line with
     	 setuid() changes.  Changes are made to the new credentials, rather
     	 than the task itself as in security_task_post_setuid().

     (*) security_task_reparent_to_init(), ->task_reparent_to_init()

     	 Removed.  Instead the task being reparented to init is referred
     	 directly to init's credentials.

	 NOTE!  This results in the loss of some state: SELinux's osid no
	 longer records the sid of the thread that forked it.

     (*) security_key_alloc(), ->key_alloc()
     (*) security_key_permission(), ->key_permission()

     	 Changed.  These now take cred pointers rather than task pointers to
     	 refer to the security context.

 (4) sys_capset().

     This has been simplified and uses less locking.  The LSM functions it
     calls have been merged.

 (5) reparent_to_kthreadd().

     This gives the current thread the same credentials as init by simply using
     commit_thread() to point that way.

 (6) __sigqueue_alloc() and switch_uid()

     __sigqueue_alloc() can't stop the target task from changing its creds
     beneath it, so this function gets a reference to the currently applicable
     user_struct which it then passes into the sigqueue struct it returns if
     successful.

     switch_uid() is now called from commit_creds(), and possibly should be
     folded into that.  commit_creds() should take care of protecting
     __sigqueue_alloc().

 (7) [sg]et[ug]id() and co and [sg]et_current_groups.

     The set functions now all use prepare_creds(), commit_creds() and
     abort_creds() to build and check a new set of credentials before applying
     it.

     security_task_set[ug]id() is called inside the prepared section.  This
     guarantees that nothing else will affect the creds until we've finished.

     The calling of set_dumpable() has been moved into commit_creds().

     Much of the functionality of set_user() has been moved into
     commit_creds().

     The get functions all simply access the data directly.

 (8) security_task_prctl() and cap_task_prctl().

     security_task_prctl() has been modified to return -ENOSYS if it doesn't
     want to handle a function, or otherwise return the return value directly
     rather than through an argument.

     Additionally, cap_task_prctl() now prepares a new set of credentials, even
     if it doesn't end up using it.

 (9) Keyrings.

     A number of changes have been made to the keyrings code:

     (a) switch_uid_keyring(), copy_keys(), exit_keys() and suid_keys() have
     	 all been dropped and built in to the credentials functions directly.
     	 They may want separating out again later.

     (b) key_alloc() and search_process_keyrings() now take a cred pointer
     	 rather than a task pointer to specify the security context.

     (c) copy_creds() gives a new thread within the same thread group a new
     	 thread keyring if its parent had one, otherwise it discards the thread
     	 keyring.

     (d) The authorisation key now points directly to the credentials to extend
     	 the search into rather pointing to the task that carries them.

     (e) Installing thread, process or session keyrings causes a new set of
     	 credentials to be created, even though it's not strictly necessary for
     	 process or session keyrings (they're shared).

(10) Usermode helper.

     The usermode helper code now carries a cred struct pointer in its
     subprocess_info struct instead of a new session keyring pointer.  This set
     of credentials is derived from init_cred and installed on the new process
     after it has been cloned.

     call_usermodehelper_setup() allocates the new credentials and
     call_usermodehelper_freeinfo() discards them if they haven't been used.  A
     special cred function (prepare_usermodeinfo_creds()) is provided
     specifically for call_usermodehelper_setup() to call.

     call_usermodehelper_setkeys() adjusts the credentials to sport the
     supplied keyring as the new session keyring.

(11) SELinux.

     SELinux has a number of changes, in addition to those to support the LSM
     interface changes mentioned above:

     (a) selinux_setprocattr() no longer does its check for whether the
     	 current ptracer can access processes with the new SID inside the lock
     	 that covers getting the ptracer's SID.  Whilst this lock ensures that
     	 the check is done with the ptracer pinned, the result is only valid
     	 until the lock is released, so there's no point doing it inside the
     	 lock.

(12) is_single_threaded().

     This function has been extracted from selinux_setprocattr() and put into
     a file of its own in the lib/ directory as join_session_keyring() now
     wants to use it too.

     The code in SELinux just checked to see whether a task shared mm_structs
     with other tasks (CLONE_VM), but that isn't good enough.  We really want
     to know if they're part of the same thread group (CLONE_THREAD).

(13) nfsd.

     The NFS server daemon now has to use the COW credentials to set the
     credentials it is going to use.  It really needs to pass the credentials
     down to the functions it calls, but it can't do that until other patches
     in this series have been applied.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:23 +11:00
David Howells
745ca2475a CRED: Pass credentials through dentry_open()
Pass credentials through dentry_open() so that the COW creds patch can have
SELinux's flush_unauthorized_files() pass the appropriate creds back to itself
when it opens its null chardev.

The security_dentry_open() call also now takes a creds pointer, as does the
dentry_open hook in struct security_operations.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:22 +11:00
David Howells
88e67f3b88 CRED: Make inode_has_perm() and file_has_perm() take a cred pointer
Make inode_has_perm() and file_has_perm() take a cred pointer rather than a
task pointer.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:21 +11:00
David Howells
275bb41e9d CRED: Wrap access to SELinux's task SID
Wrap access to SELinux's task SID, using task_sid() and current_sid() as
appropriate.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:19 +11:00
David Howells
f1752eec61 CRED: Detach the credentials from task_struct
Detach the credentials from task_struct, duplicating them in copy_process()
and releasing them in __put_task_struct().

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:17 +11:00
David Howells
b6dff3ec5e CRED: Separate task security context from task_struct
Separate the task security context from task_struct.  At this point, the
security data is temporarily embedded in the task_struct with two pointers
pointing to it.

Note that the Alpha arch is altered as it refers to (E)UID and (E)GID in
entry.S via asm-offsets.

With comment fixes Signed-off-by: Marc Dionne <marc.c.dionne@gmail.com>

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:16 +11:00
David Howells
15a2460ed0 CRED: Constify the kernel_cap_t arguments to the capset LSM hooks
Constify the kernel_cap_t arguments to the capset LSM hooks.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:15 +11:00
David Howells
1cdcbec1a3 CRED: Neuter sys_capset()
Take away the ability for sys_capset() to affect processes other than current.

This means that current will not need to lock its own credentials when reading
them against interference by other processes.

This has effectively been the case for a while anyway, since:

 (1) Without LSM enabled, sys_capset() is disallowed.

 (2) With file-based capabilities, sys_capset() is neutered.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-14 10:39:14 +11:00
Eric Paris
066746796b Currently SELinux jumps through some ugly hoops to not audit a capbility
check when determining if a process has additional powers to override
memory limits or when trying to read/write illegal file labels.  Use
the new noaudit call instead.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-11 22:02:57 +11:00
Eric Paris
06112163f5 Add a new capable interface that will be used by systems that use audit to
make an A or B type decision instead of a security decision.  Currently
this is the case at least for filesystems when deciding if a process can use
the reserved 'root' blocks and for the case of things like the oom
algorithm determining if processes are root processes and should be less
likely to be killed.  These types of security system requests should not be
audited or logged since they are not really security decisions.  It would be
possible to solve this problem like the vm_enough_memory security check did
by creating a new LSM interface and moving all of the policy into that
interface but proves the needlessly bloat the LSM and provide complex
indirection.

This merely allows those decisions to be made where they belong and to not
flood logs or printk with denials for thing that are not security decisions.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-11 22:02:50 +11:00
Eric Paris
39c9aede2b SELinux: Use unknown perm handling to handle unknown netlink msg types
Currently when SELinux has not been updated to handle a netlink message
type the operation is denied with EINVAL.  This patch will leave the
audit/warning message so things get fixed but if policy chose to allow
unknowns this will allow the netlink operation.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-09 07:33:18 +08:00
David S. Miller
9eeda9abd1 Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:

	drivers/net/wireless/ath5k/base.c
	net/8021q/vlan_core.c
2008-11-06 22:43:03 -08:00
James Morris
e21e696edb Merge branch 'master' into next 2008-11-06 07:12:34 +08:00
Eric Paris
41d9f9c524 SELinux: hold tasklist_lock and siglock while waking wait_chldexit
SELinux has long been calling wake_up_interruptible() on
current->parent->signal->wait_chldexit without holding any locks.  It
appears that this operation should hold the tasklist_lock to dereference
current->parent and we should hold the siglock when waking up the
signal->wait_chldexit.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-05 08:44:11 +11:00
Eric Paris
37dd0bd04a SELinux: properly handle empty tty_files list
SELinux has wrongly (since 2004) had an incorrect test for an empty
tty->tty_files list.  With an empty list selinux would be pointing to part
of the tty struct itself and would then proceed to dereference that value
and again dereference that result.  An F10 change to plymouth on a ppc64
system is actually currently triggering this bug.  This patch uses
list_empty() to handle empty lists rather than looking at a meaningless
location.

[note, this fixes the oops reported in
https://bugzilla.redhat.com/show_bug.cgi?id=469079]

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-11-01 09:38:48 +11:00
Eric Paris
8b6a5a37f8 SELinux: check open perms in dentry_open not inode_permission
Some operations, like searching a directory path or connecting a unix domain
socket, make explicit calls into inode_permission.  Our choices are to
either try to come up with a signature for all of the explicit calls to
inode_permission and do not check open on those, or to move the open checks to
dentry_open where we know this is always an open operation.  This patch moves
the checks to dentry_open.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-10-31 02:00:52 +11:00
Alexey Dobriyan
def8b4faff net: reduce structures when XFRM=n
ifdef out
* struct sk_buff::sp		(pointer)
* struct dst_entry::xfrm	(pointer)
* struct sock::sk_policy	(2 pointers)

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-10-28 13:24:06 -07:00
Thomas Gleixner
c465a76af6 Merge branches 'timers/clocksource', 'timers/hrtimers', 'timers/nohz', 'timers/ntp', 'timers/posixtimers' and 'timers/debug' into v28-timers-for-linus 2008-10-20 13:14:06 +02:00
Steven Whitehouse
a447c09324 vfs: Use const for kernel parser table
This is a much better version of a previous patch to make the parser
tables constant. Rather than changing the typedef, we put the "const" in
all the various places where its required, allowing the __initconst
exception for nfsroot which was the cause of the previous trouble.

This was posted for review some time ago and I believe its been in -mm
since then.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
Cc: Alexander Viro <aviro@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 10:10:37 -07:00
Linus Torvalds
8d71ff0bef Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (24 commits)
  integrity: special fs magic
  As pointed out by Jonathan Corbet, the timer must be deleted before
  ERROR: code indent should use tabs where possible
  The tpm_dev_release function is only called for platform devices, not pnp
  Protect tpm_chip_list when transversing it.
  Renames num_open to is_open, as only one process can open the file at a time.
  Remove the BKL calls from the TPM driver, which were added in the overall
  netlabel: Add configuration support for local labeling
  cipso: Add support for native local labeling and fixup mapping names
  netlabel: Changes to the NetLabel security attributes to allow LSMs to pass full contexts
  selinux: Cache NetLabel secattrs in the socket's security struct
  selinux: Set socket NetLabel based on connection endpoint
  netlabel: Add functionality to set the security attributes of a packet
  netlabel: Add network address selectors to the NetLabel/LSM domain mapping
  netlabel: Add a generic way to create ordered linked lists of network addrs
  netlabel: Replace protocol/NetLabel linking with refrerence counts
  smack: Fix missing calls to netlbl_skbuff_err()
  selinux: Fix missing calls to netlbl_skbuff_err()
  selinux: Fix a problem in security_netlbl_sid_to_secattr()
  selinux: Better local/forward check in selinux_ip_postroute()
  ...
2008-10-13 10:00:44 -07:00
Alan Cox
934e6ebf96 tty: Redo current tty locking
Currently it is sometimes locked by the tty mutex and sometimes by the
sighand lock. The latter is in fact correct and now we can hand back referenced
objects we can fix this up without problems around sleeping functions.

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:41 -07:00
Alan Cox
452a00d2ee tty: Make get_current_tty use a kref
We now return a kref covered tty reference. That ensures the tty structure
doesn't go away when you have a return from get_current_tty. This is not
enough to protect you from most of the resources being freed behind your
back - yet.

[Updated to include fixes for SELinux problems found by Andrew Morton and
 an s390 leak found while debugging the former]

Signed-off-by: Alan Cox <alan@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-10-13 09:51:41 -07:00
James Morris
0da939b005 Merge branch 'master' of git://git.infradead.org/users/pcmoore/lblnet-2.6_next into next 2008-10-11 09:26:14 +11:00
Paul Moore
6c5b3fc014 selinux: Cache NetLabel secattrs in the socket's security struct
Previous work enabled the use of address based NetLabel selectors, which
while highly useful, brought the potential for additional per-packet overhead
when used.  This patch attempts to mitigate some of that overhead by caching
the NetLabel security attribute struct within the SELinux socket security
structure.  This should help eliminate the need to recreate the NetLabel
secattr structure for each packet resulting in less overhead.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:33 -04:00
Paul Moore
014ab19a69 selinux: Set socket NetLabel based on connection endpoint
Previous work enabled the use of address based NetLabel selectors, which while
highly useful, brought the potential for additional per-packet overhead when
used.  This patch attempts to solve that by applying NetLabel socket labels
when sockets are connect()'d.  This should alleviate the per-packet NetLabel
labeling for all connected sockets (yes, it even works for connected DGRAM
sockets).

Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:33 -04:00
Paul Moore
948bf85c1b netlabel: Add functionality to set the security attributes of a packet
This patch builds upon the new NetLabel address selector functionality by
providing the NetLabel KAPI and CIPSO engine support needed to enable the
new packet-based labeling.  The only new addition to the NetLabel KAPI at
this point is shown below:

 * int netlbl_skbuff_setattr(skb, family, secattr)

... and is designed to be called from a Netfilter hook after the packet's
IP header has been populated such as in the FORWARD or LOCAL_OUT hooks.

This patch also provides the necessary SELinux hooks to support this new
functionality.  Smack support is not currently included due to uncertainty
regarding the permissions needed to expand the Smack network access controls.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Reviewed-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:32 -04:00
Paul Moore
dfaebe9825 selinux: Fix missing calls to netlbl_skbuff_err()
At some point I think I messed up and dropped the calls to netlbl_skbuff_err()
which are necessary for CIPSO to send error notifications to remote systems.
This patch re-introduces the error handling calls into the SELinux code.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:31 -04:00
Paul Moore
d8395c876b selinux: Better local/forward check in selinux_ip_postroute()
It turns out that checking to see if skb->sk is NULL is not a very good
indicator of a forwarded packet as some locally generated packets also have
skb->sk set to NULL.  Fix this by not only checking the skb->sk field but also
the IP[6]CB(skb)->flags field for the IP[6]SKB_FORWARDED flag.  While we are
at it, we are calling selinux_parse_skb() much earlier than we really should
resulting in potentially wasted cycles parsing packets for information we
might no use; so shuffle the code around a bit to fix this.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:30 -04:00
Paul Moore
aa86290089 selinux: Correctly handle IPv4 packets on IPv6 sockets in all cases
We did the right thing in a few cases but there were several areas where we
determined a packet's address family based on the socket's address family which
is not the right thing to do since we can get IPv4 packets on IPv6 sockets.
This patch fixes these problems by either taking the address family directly
from the packet.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: James Morris <jmorris@namei.org>
2008-10-10 10:16:29 -04:00
Stephen Smalley
ea6b184f7d selinux: use default proc sid on symlinks
As we are not concerned with fine-grained control over reading of
symlinks in proc, always use the default proc SID for all proc symlinks.
This should help avoid permission issues upon changes to the proc tree
as in the /proc/net -> /proc/self/net example.
This does not alter labeling of symlinks within /proc/pid directories.
ls -Zd /proc/net output before and after the patch should show the difference.

Signed-off-by:  Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-09-30 00:26:53 +10:00
Frank Mayhar
f06febc96b timers: fix itimer/many thread hang
Overview

This patch reworks the handling of POSIX CPU timers, including the
ITIMER_PROF, ITIMER_VIRT timers and rlimit handling.  It was put together
with the help of Roland McGrath, the owner and original writer of this code.

The problem we ran into, and the reason for this rework, has to do with using
a profiling timer in a process with a large number of threads.  It appears
that the performance of the old implementation of run_posix_cpu_timers() was
at least O(n*3) (where "n" is the number of threads in a process) or worse.
Everything is fine with an increasing number of threads until the time taken
for that routine to run becomes the same as or greater than the tick time, at
which point things degrade rather quickly.

This patch fixes bug 9906, "Weird hang with NPTL and SIGPROF."

Code Changes

This rework corrects the implementation of run_posix_cpu_timers() to make it
run in constant time for a particular machine.  (Performance may vary between
one machine and another depending upon whether the kernel is built as single-
or multiprocessor and, in the latter case, depending upon the number of
running processors.)  To do this, at each tick we now update fields in
signal_struct as well as task_struct.  The run_posix_cpu_timers() function
uses those fields to make its decisions.

We define a new structure, "task_cputime," to contain user, system and
scheduler times and use these in appropriate places:

struct task_cputime {
	cputime_t utime;
	cputime_t stime;
	unsigned long long sum_exec_runtime;
};

This is included in the structure "thread_group_cputime," which is a new
substructure of signal_struct and which varies for uniprocessor versus
multiprocessor kernels.  For uniprocessor kernels, it uses "task_cputime" as
a simple substructure, while for multiprocessor kernels it is a pointer:

struct thread_group_cputime {
	struct task_cputime totals;
};

struct thread_group_cputime {
	struct task_cputime *totals;
};

We also add a new task_cputime substructure directly to signal_struct, to
cache the earliest expiration of process-wide timers, and task_cputime also
replaces the it_*_expires fields of task_struct (used for earliest expiration
of thread timers).  The "thread_group_cputime" structure contains process-wide
timers that are updated via account_user_time() and friends.  In the non-SMP
case the structure is a simple aggregator; unfortunately in the SMP case that
simplicity was not achievable due to cache-line contention between CPUs (in
one measured case performance was actually _worse_ on a 16-cpu system than
the same test on a 4-cpu system, due to this contention).  For SMP, the
thread_group_cputime counters are maintained as a per-cpu structure allocated
using alloc_percpu().  The timer functions update only the timer field in
the structure corresponding to the running CPU, obtained using per_cpu_ptr().

We define a set of inline functions in sched.h that we use to maintain the
thread_group_cputime structure and hide the differences between UP and SMP
implementations from the rest of the kernel.  The thread_group_cputime_init()
function initializes the thread_group_cputime structure for the given task.
The thread_group_cputime_alloc() is a no-op for UP; for SMP it calls the
out-of-line function thread_group_cputime_alloc_smp() to allocate and fill
in the per-cpu structures and fields.  The thread_group_cputime_free()
function, also a no-op for UP, in SMP frees the per-cpu structures.  The
thread_group_cputime_clone_thread() function (also a UP no-op) for SMP calls
thread_group_cputime_alloc() if the per-cpu structures haven't yet been
allocated.  The thread_group_cputime() function fills the task_cputime
structure it is passed with the contents of the thread_group_cputime fields;
in UP it's that simple but in SMP it must also safely check that tsk->signal
is non-NULL (if it is it just uses the appropriate fields of task_struct) and,
if so, sums the per-cpu values for each online CPU.  Finally, the three
functions account_group_user_time(), account_group_system_time() and
account_group_exec_runtime() are used by timer functions to update the
respective fields of the thread_group_cputime structure.

Non-SMP operation is trivial and will not be mentioned further.

The per-cpu structure is always allocated when a task creates its first new
thread, via a call to thread_group_cputime_clone_thread() from copy_signal().
It is freed at process exit via a call to thread_group_cputime_free() from
cleanup_signal().

All functions that formerly summed utime/stime/sum_sched_runtime values from
from all threads in the thread group now use thread_group_cputime() to
snapshot the values in the thread_group_cputime structure or the values in
the task structure itself if the per-cpu structure hasn't been allocated.

Finally, the code in kernel/posix-cpu-timers.c has changed quite a bit.
The run_posix_cpu_timers() function has been split into a fast path and a
slow path; the former safely checks whether there are any expired thread
timers and, if not, just returns, while the slow path does the heavy lifting.
With the dedicated thread group fields, timers are no longer "rebalanced" and
the process_timer_rebalance() function and related code has gone away.  All
summing loops are gone and all code that used them now uses the
thread_group_cputime() inline.  When process-wide timers are set, the new
task_cputime structure in signal_struct is used to cache the earliest
expiration; this is checked in the fast path.

Performance

The fix appears not to add significant overhead to existing operations.  It
generally performs the same as the current code except in two cases, one in
which it performs slightly worse (Case 5 below) and one in which it performs
very significantly better (Case 2 below).  Overall it's a wash except in those
two cases.

I've since done somewhat more involved testing on a dual-core Opteron system.

Case 1: With no itimer running, for a test with 100,000 threads, the fixed
	kernel took 1428.5 seconds, 513 seconds more than the unfixed system,
	all of which was spent in the system.  There were twice as many
	voluntary context switches with the fix as without it.

Case 2: With an itimer running at .01 second ticks and 4000 threads (the most
	an unmodified kernel can handle), the fixed kernel ran the test in
	eight percent of the time (5.8 seconds as opposed to 70 seconds) and
	had better tick accuracy (.012 seconds per tick as opposed to .023
	seconds per tick).

Case 3: A 4000-thread test with an initial timer tick of .01 second and an
	interval of 10,000 seconds (i.e. a timer that ticks only once) had
	very nearly the same performance in both cases:  6.3 seconds elapsed
	for the fixed kernel versus 5.5 seconds for the unfixed kernel.

With fewer threads (eight in these tests), the Case 1 test ran in essentially
the same time on both the modified and unmodified kernels (5.2 seconds versus
5.8 seconds).  The Case 2 test ran in about the same time as well, 5.9 seconds
versus 5.4 seconds but again with much better tick accuracy, .013 seconds per
tick versus .025 seconds per tick for the unmodified kernel.

Since the fix affected the rlimit code, I also tested soft and hard CPU limits.

Case 4: With a hard CPU limit of 20 seconds and eight threads (and an itimer
	running), the modified kernel was very slightly favored in that while
	it killed the process in 19.997 seconds of CPU time (5.002 seconds of
	wall time), only .003 seconds of that was system time, the rest was
	user time.  The unmodified kernel killed the process in 20.001 seconds
	of CPU (5.014 seconds of wall time) of which .016 seconds was system
	time.  Really, though, the results were too close to call.  The results
	were essentially the same with no itimer running.

Case 5: With a soft limit of 20 seconds and a hard limit of 2000 seconds
	(where the hard limit would never be reached) and an itimer running,
	the modified kernel exhibited worse tick accuracy than the unmodified
	kernel: .050 seconds/tick versus .028 seconds/tick.  Otherwise,
	performance was almost indistinguishable.  With no itimer running this
	test exhibited virtually identical behavior and times in both cases.

In times past I did some limited performance testing.  those results are below.

On a four-cpu Opteron system without this fix, a sixteen-thread test executed
in 3569.991 seconds, of which user was 3568.435s and system was 1.556s.  On
the same system with the fix, user and elapsed time were about the same, but
system time dropped to 0.007 seconds.  Performance with eight, four and one
thread were comparable.  Interestingly, the timer ticks with the fix seemed
more accurate:  The sixteen-thread test with the fix received 149543 ticks
for 0.024 seconds per tick, while the same test without the fix received 58720
for 0.061 seconds per tick.  Both cases were configured for an interval of
0.01 seconds.  Again, the other tests were comparable.  Each thread in this
test computed the primes up to 25,000,000.

I also did a test with a large number of threads, 100,000 threads, which is
impossible without the fix.  In this case each thread computed the primes only
up to 10,000 (to make the runtime manageable).  System time dominated, at
1546.968 seconds out of a total 2176.906 seconds (giving a user time of
629.938s).  It received 147651 ticks for 0.015 seconds per tick, still quite
accurate.  There is obviously no comparable test without the fix.

Signed-off-by: Frank Mayhar <fmayhar@google.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
2008-09-14 16:25:35 +02:00
KaiGai Kohei
d9250dea3f SELinux: add boundary support and thread context assignment
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>
2008-08-29 00:33:33 +10:00
James Morris
86d688984d Merge branch 'master' into next 2008-08-28 10:47:34 +10:00
David Howells
5cd9c58fbe security: Fix setting of PF_SUPERPRIV by __capable()
Fix the setting of PF_SUPERPRIV by __capable() as it could corrupt the flags
the target process if that is not the current process and it is trying to
change its own flags in a different way at the same time.

__capable() is using neither atomic ops nor locking to protect t->flags.  This
patch removes __capable() and introduces has_capability() that doesn't set
PF_SUPERPRIV on the process being queried.

This patch further splits security_ptrace() in two:

 (1) security_ptrace_may_access().  This passes judgement on whether one
     process may access another only (PTRACE_MODE_ATTACH for ptrace() and
     PTRACE_MODE_READ for /proc), and takes a pointer to the child process.
     current is the parent.

 (2) security_ptrace_traceme().  This passes judgement on PTRACE_TRACEME only,
     and takes only a pointer to the parent process.  current is the child.

     In Smack and commoncap, this uses has_capability() to determine whether
     the parent will be permitted to use PTRACE_ATTACH if normal checks fail.
     This does not set PF_SUPERPRIV.

Two of the instances of __capable() actually only act on current, and so have
been changed to calls to capable().

Of the places that were using __capable():

 (1) The OOM killer calls __capable() thrice when weighing the killability of a
     process.  All of these now use has_capability().

 (2) cap_ptrace() and smack_ptrace() were using __capable() to check to see
     whether the parent was allowed to trace any process.  As mentioned above,
     these have been split.  For PTRACE_ATTACH and /proc, capable() is now
     used, and for PTRACE_TRACEME, has_capability() is used.

 (3) cap_safe_nice() only ever saw current, so now uses capable().

 (4) smack_setprocattr() rejected accesses to tasks other than current just
     after calling __capable(), so the order of these two tests have been
     switched and capable() is used instead.

 (5) In smack_file_send_sigiotask(), we need to allow privileged processes to
     receive SIGIO on files they're manipulating.

 (6) In smack_task_wait(), we let a process wait for a privileged process,
     whether or not the process doing the waiting is privileged.

I've tested this with the LTP SELinux and syscalls testscripts.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
2008-08-14 22:59:43 +10:00
David Howells
cf9481e289 SELinux: Fix a potentially uninitialised variable in SELinux hooks
Fix a potentially uninitialised variable in SELinux hooks that's given a
pointer to the network address by selinux_parse_skb() passing a pointer back
through its argument list.  By restructuring selinux_parse_skb(), the compiler
can see that the error case need not set it as the caller will return
immediately.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-08-05 10:55:47 +10:00
Adrian Bunk
3583a71183 make selinux_write_opts() static
This patch makes the needlessly global selinux_write_opts() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-08-05 10:55:24 +10:00
Eric Paris
383795c206 SELinux: /proc/mounts should show what it can
Given a hosed SELinux config in which a system never loads policy or
disables SELinux we currently just return -EINVAL for anyone trying to
read /proc/mounts.  This is a configuration problem but we can certainly
be more graceful.  This patch just ignores -EINVAL when displaying LSM
options and causes /proc/mounts display everything else it can.  If
policy isn't loaded the obviously there are no options, so we aren't
really loosing any information here.

This is safe as the only other return of EINVAL comes from
security_sid_to_context_core() in the case of an invalid sid.  Even if a
FS was mounted with a now invalidated context that sid should have been
remapped to unlabeled and so we won't hit the EINVAL and will work like
we should.  (yes, I tested to make sure it worked like I thought)

Signed-off-by: Eric Paris <eparis@redhat.com>
Tested-by: Marc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-30 08:31:28 +10:00
Linus Torvalds
4836e30078 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (39 commits)
  [PATCH] fix RLIM_NOFILE handling
  [PATCH] get rid of corner case in dup3() entirely
  [PATCH] remove remaining namei_{32,64}.h crap
  [PATCH] get rid of indirect users of namei.h
  [PATCH] get rid of __user_path_lookup_open
  [PATCH] f_count may wrap around
  [PATCH] dup3 fix
  [PATCH] don't pass nameidata to __ncp_lookup_validate()
  [PATCH] don't pass nameidata to gfs2_lookupi()
  [PATCH] new (local) helper: user_path_parent()
  [PATCH] sanitize __user_walk_fd() et.al.
  [PATCH] preparation to __user_walk_fd cleanup
  [PATCH] kill nameidata passing to permission(), rename to inode_permission()
  [PATCH] take noexec checks to very few callers that care
  Re: [PATCH 3/6] vfs: open_exec cleanup
  [patch 4/4] vfs: immutable inode checking cleanup
  [patch 3/4] fat: dont call notify_change
  [patch 2/4] vfs: utimes cleanup
  [patch 1/4] vfs: utimes: move owner check into inode_change_ok()
  [PATCH] vfs: use kstrdup() and check failing allocation
  ...
2008-07-26 20:23:44 -07:00
Linus Torvalds
2284284281 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
  netns: fix ip_rt_frag_needed rt_is_expired
  netfilter: nf_conntrack_extend: avoid unnecessary "ct->ext" dereferences
  netfilter: fix double-free and use-after free
  netfilter: arptables in netns for real
  netfilter: ip{,6}tables_security: fix future section mismatch
  selinux: use nf_register_hooks()
  netfilter: ebtables: use nf_register_hooks()
  Revert "pkt_sched: sch_sfq: dump a real number of flows"
  qeth: use dev->ml_priv instead of dev->priv
  syncookies: Make sure ECN is disabled
  net: drop unused BUG_TRAP()
  net: convert BUG_TRAP to generic WARN_ON
  drivers/net: convert BUG_TRAP to generic WARN_ON
2008-07-26 20:17:56 -07:00
Al Viro
b77b0646ef [PATCH] pass MAY_OPEN to vfs_permission() explicitly
... and get rid of the last "let's deduce mask from nameidata->flags"
bit.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-07-26 20:53:22 -04:00
Alexey Dobriyan
6c5a9d2e15 selinux: use nf_register_hooks()
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2008-07-26 17:48:15 -07:00
Roland McGrath
0d094efeb1 tracehook: tracehook_tracer_task
This adds the tracehook_tracer_task() hook to consolidate all forms of
"Who is using ptrace on me?" logic.  This is used for "TracerPid:" in
/proc and for permission checks.  We also clean up the selinux code the
called an identical accessor.

Signed-off-by: Roland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-07-26 12:00:08 -07:00
James Morris
089be43e40 Revert "SELinux: allow fstype unknown to policy to use xattrs if present"
This reverts commit 811f379927.

From Eric Paris:

"Please drop this patch for now.  It deadlocks on ntfs-3g.  I need to
rework it to handle fuse filesystems better.  (casey was right)"
2008-07-15 18:32:49 +10:00
James Morris
6f0f0fd496 security: remove register_security hook
The register security hook is no longer required, as the capability
module is always registered.  LSMs wishing to stack capability as
a secondary module should do so explicitly.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
2008-07-14 15:04:06 +10:00
Miklos Szeredi
b478a9f988 security: remove unused sb_get_mnt_opts hook
The sb_get_mnt_opts() hook is unused, and is superseded by the
sb_show_options() hook.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Acked-by: James Morris <jmorris@namei.org>
2008-07-14 15:02:05 +10:00
Eric Paris
2069f45784 LSM/SELinux: show LSM mount options in /proc/mounts
This patch causes SELinux mount options to show up in /proc/mounts.  As
with other code in the area seq_put errors are ignored.  Other LSM's
will not have their mount options displayed until they fill in their own
security_sb_show_options() function.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:02:05 +10:00
Eric Paris
811f379927 SELinux: allow fstype unknown to policy to use xattrs if present
Currently if a FS is mounted for which SELinux policy does not define an
fs_use_* that FS will either be genfs labeled or not labeled at all.
This decision is based on the existence of a genfscon rule in policy and
is irrespective of the capabilities of the filesystem itself.  This
patch allows the kernel to check if the filesystem supports security
xattrs and if so will use those if there is no fs_use_* rule in policy.
An fstype with a no fs_use_* rule but with a genfs rule will use xattrs
if available and will follow the genfs rule.

This can be particularly interesting for things like ecryptfs which
actually overlays a real underlying FS.  If we define excryptfs in
policy to use xattrs we will likely get this wrong at times, so with
this path we just don't need to define it!

Overlay ecryptfs on top of NFS with no xattr support:
SELinux: initialized (dev ecryptfs, type ecryptfs), uses genfs_contexts
Overlay ecryptfs on top of ext4 with xattr support:
SELinux: initialized (dev ecryptfs, type ecryptfs), uses xattr

It is also useful as the kernel adds new FS we don't need to add them in
policy if they support xattrs and that is how we want to handle them.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:02:04 +10:00
James Morris
2baf06df85 SELinux: use do_each_thread as a proper do/while block
Use do_each_thread as a proper do/while block.  Sparse complained.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2008-07-14 15:02:02 +10:00
James Morris
e399f98224 SELinux: remove unused and shadowed addrlen variable
Remove unused and shadowed addrlen variable.  Picked up by sparse.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Paul Moore <paul.moore@hp.com>
2008-07-14 15:02:01 +10:00
Stephen Smalley
242631c49d selinux: simplify ioctl checking
Simplify and improve the robustness of the SELinux ioctl checking by
using the "access mode" bits of the ioctl command to determine the
permission check rather than dealing with individual command values.
This removes any knowledge of specific ioctl commands from SELinux
and follows the same guidance we gave to Smack earlier.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:01:53 +10:00
Stephen Smalley
abc69bb633 SELinux: enable processes with mac_admin to get the raw inode contexts
Enable processes with CAP_MAC_ADMIN + mac_admin permission in policy
to get undefined contexts on inodes.  This extends the support for
deferred mapping of security contexts in order to permit restorecon
and similar programs to see the raw file contexts unknown to the
system policy in order to check them.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:01:52 +10:00
Stephen Smalley
006ebb40d3 Security: split proc ptrace checking into read vs. attach
Enable security modules to distinguish reading of process state via
proc from full ptrace access by renaming ptrace_may_attach to
ptrace_may_access and adding a mode argument indicating whether only
read access or full attach access is requested.  This allows security
modules to permit access to reading process state without granting
full ptrace access.  The base DAC/capability checking remains unchanged.

Read access to /proc/pid/mem continues to apply a full ptrace attach
check since check_mem_permission() already requires the current task
to already be ptracing the target.  The other ptrace checks within
proc for elements like environ, maps, and fds are changed to pass the
read mode instead of attach.

In the SELinux case, we model such reading of process state as a
reading of a proc file labeled with the target process' label.  This
enables SELinux policy to permit such reading of process state without
permitting control or manipulation of the target process, as there are
a number of cases where programs probe for such information via proc
but do not need to be able to control the target (e.g. procps,
lsof, PolicyKit, ConsoleKit).  At present we have to choose between
allowing full ptrace in policy (more permissive than required/desired)
or breaking functionality (or in some cases just silencing the denials
via dontaudit rules but this can hide genuine attacks).

This version of the patch incorporates comments from Casey Schaufler
(change/replace existing ptrace_may_attach interface, pass access
mode), and Chris Wright (provide greater consistency in the checking).

Note that like their predecessors __ptrace_may_attach and
ptrace_may_attach, the __ptrace_may_access and ptrace_may_access
interfaces use different return value conventions from each other (0
or -errno vs. 1 or 0).  I retained this difference to avoid any
changes to the caller logic but made the difference clearer by
changing the latter interface to return a bool rather than an int and
by adding a comment about it to ptrace.h for any future callers.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:01:47 +10:00
Eric Paris
f526971078 SELinux: keep the code clean formating and syntax
Formatting and syntax changes

whitespace, tabs to spaces, trailing space
put open { on same line as struct def
remove unneeded {} after if statements
change printk("Lu") to printk("llu")
convert asm/uaccess.h to linux/uaacess.h includes
remove unnecessary asm/bug.h includes
convert all users of simple_strtol to strict_strtol

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:01:36 +10:00
Stephen Smalley
12b29f3455 selinux: support deferred mapping of contexts
Introduce SELinux support for deferred mapping of security contexts in
the SID table upon policy reload, and use this support for inode
security contexts when the context is not yet valid under the current
policy.  Only processes with CAP_MAC_ADMIN + mac_admin permission in
policy can set undefined security contexts on inodes.  Inodes with
such undefined contexts are treated as having the unlabeled context
until the context becomes valid upon a policy reload that defines the
context.  Context invalidation upon policy reload also uses this
support to save the context information in the SID table and later
recover it upon a subsequent policy reload that defines the context
again.

This support is to enable package managers and similar programs to set
down file contexts unknown to the system policy at the time the file
is created in order to better support placing loadable policy modules
in packages and to support build systems that need to create images of
different distro releases with different policies w/o requiring all of
the contexts to be defined or legal in the build host policy.

With this patch applied, the following sequence is possible, although
in practice it is recommended that this permission only be allowed to
specific program domains such as the package manager.

# rmdir baz
# rm bar
# touch bar
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument
# cat setundefined.te
policy_module(setundefined, 1.0)
require {
	type unconfined_t;
	type unlabeled_t;
}
files_type(unlabeled_t)
allow unconfined_t self:capability2 mac_admin;
# make -f /usr/share/selinux/devel/Makefile setundefined.pp
# semodule -i setundefined.pp
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
# mkdir -Z system_u:object_r:foo_exec_t baz
# ls -Zd bar baz
-rw-r--r--  root root system_u:object_r:unlabeled_t    bar
drwxr-xr-x  root root system_u:object_r:unlabeled_t    baz
# cat foo.te
policy_module(foo, 1.0)
type foo_exec_t;
files_type(foo_exec_t)
# make -f /usr/share/selinux/devel/Makefile foo.pp
# semodule -i foo.pp # defines foo_exec_t
# ls -Zd bar baz
-rw-r--r--  root root user_u:object_r:foo_exec_t       bar
drwxr-xr-x  root root system_u:object_r:foo_exec_t    baz
# semodule -r foo
# ls -Zd bar baz
-rw-r--r--  root root system_u:object_r:unlabeled_t    bar
drwxr-xr-x  root root system_u:object_r:unlabeled_t    baz
# semodule -i foo.pp
# ls -Zd bar baz
-rw-r--r--  root root user_u:object_r:foo_exec_t       bar
drwxr-xr-x  root root system_u:object_r:foo_exec_t    baz
# semodule -r setundefined foo
# chcon -t foo_exec_t bar # no longer defined and not allowed
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# rmdir baz
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-07-14 15:01:34 +10:00
Al Viro
9f3acc3140 [PATCH] split linux/file.h
Initial splitoff of the low-level stuff; taken to fdtable.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-05-01 13:08:16 -04:00
Oleg Nesterov
3b5e9e53c6 signals: cleanup security_task_kill() usage/implementation
Every implementation of ->task_kill() does nothing when the signal comes from
the kernel.  This is correct, but means that check_kill_permission() should
call security_task_kill() only for SI_FROMUSER() case, and we can remove the
same check from ->task_kill() implementations.

(sadly, check_kill_permission() is the last user of signal->session/__session
 but we can't s/task_session_nr/task_session/ here).

NOTE: Eric W.  Biederman pointed out cap_task_kill() should die, and I think
he is very right.

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: David Quigley <dpquigl@tycho.nsa.gov>
Cc: Eric Paris <eparis@redhat.com>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-30 08:29:34 -07:00
David Howells
7bf570dc8d Security: Make secctx_to_secid() take const secdata
Make secctx_to_secid() take constant secdata.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 13:22:56 -07:00
David Howells
69664cf16a keys: don't generate user and user session keyrings unless they're accessed
Don't generate the per-UID user and user session keyrings unless they're
explicitly accessed.  This solves a problem during a login process whereby
set*uid() is called before the SELinux PAM module, resulting in the per-UID
keyrings having the wrong security labels.

This also cures the problem of multiple per-UID keyrings sometimes appearing
due to PAM modules (including pam_keyinit) setuiding and causing user_structs
to come into and go out of existence whilst the session keyring pins the user
keyring.  This is achieved by first searching for extant per-UID keyrings
before inventing new ones.

The serial bound argument is also dropped from find_keyring_by_name() as it's
not currently made use of (setting it to 0 disables the feature).

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:17 -07:00
David Howells
70a5bb72b5 keys: add keyctl function to get a security label
Add a keyctl() function to get the security label of a key.

The following is added to Documentation/keys.txt:

 (*) Get the LSM security context attached to a key.

	long keyctl(KEYCTL_GET_SECURITY, key_serial_t key, char *buffer,
		    size_t buflen)

     This function returns a string that represents the LSM security context
     attached to a key in the buffer provided.

     Unless there's an error, it always returns the amount of data it could
     produce, even if that's too big for the buffer, but it won't copy more
     than requested to userspace. If the buffer pointer is NULL then no copy
     will take place.

     A NUL character is included at the end of the string if the buffer is
     sufficiently big.  This is included in the returned count.  If no LSM is
     in force then an empty string will be returned.

     A process must have view permission on the key for this function to be
     successful.

[akpm@linux-foundation.org: declare keyctl_get_security()]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Paul Moore <paul.moore@hp.com>
Cc: Chris Wright <chrisw@sous-sol.org>
Cc: James Morris <jmorris@namei.org>
Cc: Kevin Coffman <kwc@citi.umich.edu>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:16 -07:00
David Howells
8f0cfa52a1 xattr: add missing consts to function arguments
Add missing consts to xattr function arguments.

Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Andreas Gruenbacher <agruen@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-29 08:06:06 -07:00
Andrew G. Morgan
3898b1b4eb capabilities: implement per-process securebits
Filesystem capability support makes it possible to do away with (set)uid-0
based privilege and use capabilities instead.  That is, with filesystem
support for capabilities but without this present patch, it is (conceptually)
possible to manage a system with capabilities alone and never need to obtain
privilege via (set)uid-0.

Of course, conceptually isn't quite the same as currently possible since few
user applications, certainly not enough to run a viable system, are currently
prepared to leverage capabilities to exercise privilege.  Further, many
applications exist that may never get upgraded in this way, and the kernel
will continue to want to support their setuid-0 base privilege needs.

Where pure-capability applications evolve and replace setuid-0 binaries, it is
desirable that there be a mechanisms by which they can contain their
privilege.  In addition to leveraging the per-process bounding and inheritable
sets, this should include suppressing the privilege of the uid-0 superuser
from the process' tree of children.

The feature added by this patch can be leveraged to suppress the privilege
associated with (set)uid-0.  This suppression requires CAP_SETPCAP to
initiate, and only immediately affects the 'current' process (it is inherited
through fork()/exec()).  This reimplementation differs significantly from the
historical support for securebits which was system-wide, unwieldy and which
has ultimately withered to a dead relic in the source of the modern kernel.

With this patch applied a process, that is capable(CAP_SETPCAP), can now drop
all legacy privilege (through uid=0) for itself and all subsequently
fork()'d/exec()'d children with:

  prctl(PR_SET_SECUREBITS, 0x2f);

This patch represents a no-op unless CONFIG_SECURITY_FILE_CAPABILITIES is
enabled at configure time.

[akpm@linux-foundation.org: fix uninitialised var warning]
[serue@us.ibm.com: capabilities: use cap_task_prctl when !CONFIG_SECURITY]
Signed-off-by: Andrew G. Morgan <morgan@kernel.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Reviewed-by: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Paul Moore <paul.moore@hp.com>
Signed-off-by: Serge E. Hallyn <serue@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-04-28 08:58:26 -07:00
Linus Torvalds
94bc891b00 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6:
  [PATCH] get rid of __exit_files(), __exit_fs() and __put_fs_struct()
  [PATCH] proc_readfd_common() race fix
  [PATCH] double-free of inode on alloc_file() failure exit in create_write_pipe()
  [PATCH] teach seq_file to discard entries
  [PATCH] umount_tree() will unhash everything itself
  [PATCH] get rid of more nameidata passing in namespace.c
  [PATCH] switch a bunch of LSM hooks from nameidata to path
  [PATCH] lock exclusively in collect_mounts() and drop_collected_mounts()
  [PATCH] move a bunch of declarations to fs/internal.h
2008-04-22 18:28:34 -07:00
Al Viro
b5266eb4c8 [PATCH] switch a bunch of LSM hooks from nameidata to path
Namely, ones from namespace.c

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2008-04-21 23:13:23 -04:00
Eric Paris
0f5e64200f SELinux: no BUG_ON(!ss_initialized) in selinux_clone_mnt_opts
The Fedora installer actually makes multiple NFS mounts before it loads
selinux policy.  The code in selinux_clone_mnt_opts() assumed that the
init process would always be loading policy before NFS was up and
running.  It might be possible to hit this in a diskless environment as
well, I'm not sure.  There is no need to BUG_ON() in this situation
since we can safely continue given the circumstances.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-22 10:00:09 +10:00
Eric Paris
828dfe1da5 SELinux: whitespace and formating fixes for hooks.c
All whitespace and formatting.  Nothing interesting to see here.  About
the only thing to remember is that we aren't supposed to initialize
static variables to 0/NULL.  It is done for us and doing it ourselves
puts them in a different section.

With this patch running checkpatch.pl against hooks.c only gives us
complaints about busting the 80 character limit and declaring extern's
in .c files.  Apparently they don't like it, but I don't feel like going
to the trouble of moving those to .h files...

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-21 19:11:56 +10:00
Eric Paris
744ba35e45 SELinux: clean up printks
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>
2008-04-21 19:09:26 +10:00
Ahmed S. Darwish
076c54c5bc Security: Introduce security= boot parameter
Add the security= boot parameter. This is done to avoid LSM
registration clashes in case of more than one bult-in module.

User can choose a security module to enable at boot. If no
security= boot parameter is specified, only the first LSM
asking for registration will be loaded. An invalid security
module name will be treated as if no module has been chosen.

LSM modules must check now if they are allowed to register
by calling security_module_enable(ops) first. Modify SELinux
and SMACK to do so.

Do not let SMACK register smackfs if it was not chosen on
boot. Smackfs assumes that smack hooks are registered and
the initial task security setup (swapper->security) is done.

Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
2008-04-19 10:00:51 +10:00
Ahmed S. Darwish
9d57a7f9e2 SELinux: use new audit hooks, remove redundant exports
Setup the new Audit LSM hooks for SELinux.
Remove the now redundant exported SELinux Audit interface.

Audit: Export 'audit_krule' and 'audit_field' to the public
since their internals are needed by the implementation of the
new LSM hook 'audit_rule_known'.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
2008-04-19 09:53:46 +10:00
Ahmed S. Darwish
713a04aeab SELinux: setup new inode/ipc getsecid hooks
Setup the new inode_getsecid and ipc_getsecid() LSM hooks
for SELinux.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Ahmed S. Darwish <darwish.07@gmail.com>
Acked-by: James Morris <jmorris@namei.org>
Reviewed-by: Paul Moore <paul.moore@hp.com>
2008-04-19 09:52:33 +10:00
Paul Moore
3e11217263 SELinux: Add network port SID cache
Much like we added a network node cache, this patch adds a network port
cache. The design is taken almost completely from the network node cache
which in turn was taken from the network interface cache.  The basic idea is
to cache entries in a hash table based on protocol/port information.  The
hash function only takes the port number into account since the number of
different protocols in use at any one time is expected to be relatively
small.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:16 +10:00
Eric Paris
832cbd9aa1 SELinux: turn mount options strings into defines
Convert the strings used for mount options into #defines rather than
retyping the string throughout the SELinux code.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:13 +10:00
Roland McGrath
0356357c51 selinux: remove ptrace_sid
This changes checks related to ptrace to get rid of the ptrace_sid tracking.
It's good to disentangle the security model from the ptrace implementation
internals.  It's sufficient to check against the SID of the ptracer at the
time a tracee attempts a transition.

Signed-off-by: Roland McGrath <roland@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:10 +10:00
Andrew Morton
f0115e6c89 security: code cleanup
ERROR: "(foo*)" should be "(foo *)"
#168: FILE: security/selinux/hooks.c:2656:
+		       "%s, rc=%d\n", __func__, (char*)value, -rc);

total: 1 errors, 0 warnings, 195 lines checked

./patches/security-replace-remaining-__function__-occurences.patch has style problems, please review.  If any of these errors
are false positives report them to the maintainer, see
CHECKPATCH in MAINTAINERS.

Please run checkpatch prior to sending patches

Cc: Harvey Harrison <harvey.harrison@gmail.com>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:08 +10:00
Harvey Harrison
dd6f953adb security: replace remaining __FUNCTION__ occurrences
__FUNCTION__ is gcc-specific, use __func__

Signed-off-by: Harvey Harrison <harvey.harrison@gmail.com>
Cc: James Morris <jmorris@namei.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:07 +10:00
Eric Paris
b0c636b999 SELinux: create new open permission
Adds a new open permission inside SELinux when 'opening' a file.  The idea
is that opening a file and reading/writing to that file are not the same
thing.  Its different if a program had its stdout redirected to /tmp/output
than if the program tried to directly open /tmp/output. This should allow
policy writers to more liberally give read/write permissions across the
policy while still blocking many design and programing flaws SELinux is so
good at catching today.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:06 +10:00
James Morris
98e9894650 SELinux: remove unused backpointers from security objects
Remove unused backpoiters from security objects.

Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:04 +10:00
Paul Moore
f74af6e816 SELinux: Correct the NetLabel locking for the sk_security_struct
The RCU/spinlock locking approach for the nlbl_state in the sk_security_struct
was almost certainly overkill.  This patch removes both the RCU and spinlock
locking, relying on the existing socket locks to handle the case of multiple
writers.  This change also makes several code reductions possible.

Less locking, less code - it's a Good Thing.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-18 20:26:03 +10:00
Eric Paris
5a55261716 SELinux: don't BUG if fs reuses a superblock
I (wrongly) assumed that nfs_xdev_get_sb() would not ever share a superblock
and so cloning mount options would always be correct.  Turns out that isn't
the case and we could fall over a BUG_ON() that wasn't a BUG at all.  Since
there is little we can do to reconcile different mount options this patch
just leaves the sb alone and the first set of options wins.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Trond Myklebust <trond.myklebust@fys.uio.no>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-10 08:51:01 +10:00
Stephen Smalley
869ab5147e SELinux: more GFP_NOFS fixups to prevent selinux from re-entering the fs code
More cases where SELinux must not re-enter the fs code. Called from the
d_instantiate security hook.

Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-08 08:30:14 +10:00
Josef Bacik
a02fe13297 selinux: prevent rentry into the FS
BUG fix.  Keep us from re-entering the fs when we aren't supposed to.

See discussion at
http://marc.info/?t=120716967100004&r=1&w=2

Signed-off-by: Josef Bacik <jbacik@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-04 09:35:05 +11:00
Stephen Smalley
0794c66d49 selinux: handle files opened with flags 3 by checking ioctl permission
Handle files opened with flags 3 by checking ioctl permission.

Default to returning FILE__IOCTL from file_to_av() if the f_mode has neither
FMODE_READ nor FMODE_WRITE, and thus check ioctl permission on exec or
transfer, thereby validating such descriptors early as with normal r/w
descriptors and catching leaks of them prior to attempted usage.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-04-02 16:05:52 +11:00
Adrian Bunk
2e1479d95d make selinux_parse_opts_str() static
This patch makes the needlessly global selinux_parse_opts_str() static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-03-18 09:17:22 +11:00
Eric Paris
e000752989 LSM/SELinux: Interfaces to allow FS to control mount options
Introduce new LSM interfaces to allow an FS to deal with their own mount
options.  This includes a new string parsing function exported from the
LSM that an FS can use to get a security data blob and a new security
data blob.  This is particularly useful for an FS which uses binary
mount data, like NFS, which does not pass strings into the vfs to be
handled by the loaded LSM.  Also fix a BUG() in both SELinux and SMACK
when dealing with binary mount data.  If the binary mount data is less
than one page the copy_page() in security_sb_copy_data() can cause an
illegal page fault and boom.  Remove all NFSisms from the SELinux code
since they were broken by past NFS changes.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-03-06 08:40:53 +11:00
Jan Blunck
44707fdf59 d_path: Use struct path in struct avc_audit_data
audit_log_d_path() is a d_path() wrapper that is used by the audit code.  To
use a struct path in audit_log_d_path() I need to embed it into struct
avc_audit_data.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Christoph Hellwig <hch@infradead.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "J. Bruce Fields" <bfields@fieldses.org>
Cc: Neil Brown <neilb@suse.de>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:17:08 -08:00
Jan Blunck
4ac9137858 Embed a struct path into struct nameidata instead of nd->{dentry,mnt}
This is the central patch of a cleanup series. In most cases there is no good
reason why someone would want to use a dentry for itself. This series reflects
that fact and embeds a struct path into nameidata.

Together with the other patches of this series
- it enforced the correct order of getting/releasing the reference count on
  <dentry,vfsmount> pairs
- it prepares the VFS for stacking support since it is essential to have a
  struct path in every place where the stack can be traversed
- it reduces the overall code size:

without patch series:
   text    data     bss     dec     hex filename
5321639  858418  715768 6895825  6938d1 vmlinux

with patch series:
   text    data     bss     dec     hex filename
5320026  858418  715768 6894212  693284 vmlinux

This patch:

Switch from nd->{dentry,mnt} to nd->path.{dentry,mnt} everywhere.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: fix cifs]
[akpm@linux-foundation.org: fix smack]
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Andreas Gruenbacher <agruen@suse.de>
Acked-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-14 21:13:33 -08:00
Stephen Smalley
b68e418c44 selinux: support 64-bit capabilities
Fix SELinux to handle 64-bit capabilities correctly, and to catch
future extensions of capabilities beyond 64 bits to ensure that SELinux
is properly updated.

Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2008-02-11 20:30:02 +11:00
David P. Quigley
4249259404 VFS/Security: Rework inode_getsecurity and callers to return resulting buffer
This patch modifies the interface to inode_getsecurity to have the function
return a buffer containing the security blob and its length via parameters
instead of relying on the calling function to give it an appropriately sized
buffer.

Security blobs obtained with this function should be freed using the
release_secctx LSM hook.  This alleviates the problem of the caller having to
guess a length and preallocate a buffer for this function allowing it to be
used elsewhere for Labeled NFS.

The patch also removed the unused err parameter.  The conversion is similar to
the one performed by Al Viro for the security_getprocattr hook.

Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Chris Wright <chrisw@sous-sol.org>
Acked-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2008-02-05 09:44:20 -08:00
Adrian Bunk
374ea019ca selinux: make selinux_set_mnt_opts() static
selinux_set_mnt_opts() can become static.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:44 +11:00
Paul Moore
71f1cb05f7 SELinux: Add warning messages on network denial due to error
Currently network traffic can be sliently dropped due to non-avc errors which
can lead to much confusion when trying to debug the problem.  This patch adds
warning messages so that when these events occur there is a user visible
notification.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:30 +11:00
Paul Moore
effad8df44 SELinux: Add network ingress and egress control permission checks
This patch implements packet ingress/egress controls for SELinux which allow
SELinux security policy to control the flow of all IPv4 and IPv6 packets into
and out of the system.  Currently SELinux does not have proper control over
forwarded packets and this patch corrects this problem.

Special thanks to Venkat Yekkirala <vyekkirala@trustedcs.com> whose earlier
work on this topic eventually led to this patch.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:30 +11:00
Paul Moore
5dbe1eb0cf SELinux: Allow NetLabel to directly cache SIDs
Now that the SELinux NetLabel "base SID" is always the netmsg initial SID we
can do a big optimization - caching the SID and not just the MLS attributes.
This not only saves a lot of per-packet memory allocations and copies but it
has a nice side effect of removing a chunk of code.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:27 +11:00
Paul Moore
d621d35e57 SELinux: Enable dynamic enable/disable of the network access checks
This patch introduces a mechanism for checking when labeled IPsec or SECMARK
are in use by keeping introducing a configuration reference counter for each
subsystem.  In the case of labeled IPsec, whenever a labeled SA or SPD entry
is created the labeled IPsec/XFRM reference count is increased and when the
entry is removed it is decreased.  In the case of SECMARK, when a SECMARK
target is created the reference count is increased and later decreased when the
target is removed.  These reference counters allow SELinux to quickly determine
if either of these subsystems are enabled.

NetLabel already has a similar mechanism which provides the netlbl_enabled()
function.

This patch also renames the selinux_relabel_packet_permission() function to
selinux_secmark_relabel_packet_permission() as the original name and
description were misleading in that they referenced a single packet label which
is not the case.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:26 +11:00
Paul Moore
220deb966e SELinux: Better integration between peer labeling subsystems
Rework the handling of network peer labels so that the different peer labeling
subsystems work better together.  This includes moving both subsystems to a
single "peer" object class which involves not only changes to the permission
checks but an improved method of consolidating multiple packet peer labels.
As part of this work the inbound packet permission check code has been heavily
modified to handle both the old and new behavior in as sane a fashion as
possible.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:25 +11:00
Paul Moore
224dfbd81e SELinux: Add a network node caching mechanism similar to the sel_netif_*() functions
This patch adds a SELinux IP address/node SID caching mechanism similar to the
sel_netif_*() functions.  The node SID queries in the SELinux hooks files are
also modified to take advantage of this new functionality.  In addition, remove
the address length information from the sk_buff parsing routines as it is
redundant since we already have the address family.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:23 +11:00
Paul Moore
da5645a28a SELinux: Only store the network interface's ifindex
Instead of storing the packet's network interface name store the ifindex.  This
allows us to defer the need to lookup the net_device structure until the audit
record is generated meaning that in the majority of cases we never need to
bother with this at all.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:22 +11:00
Paul Moore
e8bfdb9d0d SELinux: Convert the netif code to use ifindex values
The current SELinux netif code requires the caller have a valid net_device
struct pointer to lookup network interface information.  However, we don't
always have a valid net_device pointer so convert the netif code to use
the ifindex values we always have as part of the sk_buff.  This patch also
removes the default message SID from the network interface record, it is
not being used and therefore is "dead code".

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:21 +11:00
Paul Moore
75e22910cf NetLabel: Add IP address family information to the netlbl_skbuff_getattr() function
In order to do any sort of IP header inspection of incoming packets we need to
know which address family, AF_INET/AF_INET6/etc., it belongs to and since the
sk_buff structure does not store this information we need to pass along the
address family separate from the packet itself.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2008-01-30 08:17:20 +11:00