unregister_key_type() has code to mark a key as dead and make it unavailable in
one loop and then destroy all those unavailable key payloads in the next loop.
However, the loop to mark keys dead renders the key undetectable to the second
loop by changing the key type pointer also.

Fix this by the following means:

 (1) The key code has two garbage collectors: one deletes unreferenced keys and
     the other alters keyrings to delete links to old dead, revoked and expired
     keys.  They can end up holding each other up as both want to scan the key
     serial tree under spinlock.  Combine these into a single routine.

 (2) Move the dead key marking, dead link removal and dead key removal into the
     garbage collector as a three phase process running over the three cycles
     of the normal garbage collection procedure.  This is tracked by the
     KEY_GC_REAPING_DEAD_1, _2 and _3 state flags.

     unregister_key_type() then just unlinks the key type from the list, wakes
     up the garbage collector and waits for the third phase to complete.

 (3) Downgrade the key types sem in unregister_key_type() once it has deleted
     the key type from the list so that it doesn't block the keyctl() syscall.

 (4) Dead keys that cannot be simply removed in the third phase have their
     payloads destroyed with the key's semaphore write-locked to prevent
     interference by the keyctl() syscall.  There should be no in-kernel users
     of dead keys of that type by the point of unregistration, though keyctl()
     may be holding a reference.

 (5) Only perform timer recalculation in the GC if the timer actually expired.
     If it didn't, we'll get another cycle when it goes off - and if the key
     that actually triggered it has been removed, it's not a problem.

 (6) Only garbage collect link if the timer expired or if we're doing dead key
     clean up phase 2.

 (7) As only key_garbage_collector() is permitted to use rb_erase() on the key
     serial tree, it doesn't need to revalidate its cursor after dropping the
     spinlock as the node the cursor points to must still exist in the tree.

 (8) Drop the spinlock in the GC if there is contention on it or if we need to
     reschedule.  After dealing with that, get the spinlock again and resume
     scanning.

This has been tested in the following ways:

 (1) Run the keyutils testsuite against it.

 (2) Using the AF_RXRPC and RxKAD modules to test keytype removal:

     Load the rxrpc_s key type:

	# insmod /tmp/af-rxrpc.ko
	# insmod /tmp/rxkad.ko

     Create a key (http://people.redhat.com/~dhowells/rxrpc/listen.c):

	# /tmp/listen &
	[1] 8173

     Find the key:

	# grep rxrpc_s /proc/keys
	091086e1 I--Q--     1 perm 39390000     0     0 rxrpc_s   52:2

     Link it to a session keyring, preferably one with a higher serial number:

	# keyctl link 0x20e36251 @s

     Kill the process (the key should remain as it's linked to another place):

	# fg
	/tmp/listen
	^C

     Remove the key type:

	rmmod rxkad
	rmmod af-rxrpc

     This can be made a more effective test by altering the following part of
     the patch:

	if (unlikely(gc_state & KEY_GC_REAPING_DEAD_2)) {
		/* Make sure everyone revalidates their keys if we marked a
		 * bunch as being dead and make sure all keyring ex-payloads
		 * are destroyed.
		 */
		kdebug("dead sync");
		synchronize_rcu();

     To call synchronize_rcu() in GC phase 1 instead.  That causes that the
     keyring's old payload content to hang around longer until it's RCU
     destroyed - which usually happens after GC phase 3 is complete.  This
     allows the destroy_dead_key branch to be tested.
Reported-by: NBenjamin Coddington <bcodding@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The dead key link reaper should be non-reentrant as it relies on global state
to keep track of where it's got to when it returns to the work queue manager to
give it some air.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Make the key reaper non-reentrant by sticking it on the appropriate system work
queue when we queue it.  This will allow it to have global state and drop
locks.  It should probably be non-reentrant already as it may spend a long time
holding the key serial spinlock, and so multiple entrants can spend long
periods of time just sitting there spinning, waiting to get the lock.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Move the unreferenced key reaper function to the keys garbage collector file
as that's a more appropriate place with the dead key link reaper.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix prepare_kernel_cred() to provide a new, separate thread_group_cred struct
otherwise when using request_key() ____call_usermodehelper() calls
umh_keys_init() with the new creds pointing to init_tgcred, which
umh_keys_init() then blithely alters.

The problem can be demonstrated by:

	# keyctl request2 user a debug:a @s
	249681132
	# grep req /proc/keys
	079906a5 I--Q--     1 perm 1f3f0000     0     0 keyring   _req.249681132: 1/4
	38ef1626 IR----     1 expd 0b010000     0     0 .request_ key:ee1d4ec pid:4371 ci:1

The keyring _req.XXXX should have gone away, but something (init_tgcred) is
pinning it.

That key actually requested can then be removed and a new one created:

	# keyctl unlink 249681132
	1 links removed
	[root@andromeda ~]# grep req /proc/keys
	116cecac IR----     1 expd 0b010000     0     0 .request_ key:eeb4911 pid:4379 ci:1
	36d1cbf8 I--Q--     1 perm 1f3f0000     0     0 keyring   _req.250300689: 1/4

which causes the old _req keyring to go away and a new one to take its place.

This is a consequence of the changes in:

	commit 87966996
	Author: David Howells <dhowells@redhat.com>
	Date:   Fri Jun 17 11:25:59 2011 +0100
	KEYS/DNS: Fix ____call_usermodehelper() to not lose the session keyring

and:

	commit 17f60a7d
	Author: Eric Paris <eparis@redhat.com>
	Date:   Fri Apr 1 17:07:50 2011 -0400
	capabilites: allow the application of capability limits to usermode helpers

After this patch is applied, the _req keyring and the .request_key key are
cleaned up.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
cc: Eric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

__key_link() should use the RCU deref wrapper rcu_dereference_locked_keyring()
for accessing keyring payloads rather than calling rcu_dereference_protected()
directly.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The keyctl call:

	keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 1)

should create a session keyring if the process doesn't have one of its own
because the create flag argument is set - rather than subscribing to and
returning the user-session keyring as:

	keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0)

will do.

This can be tested by commenting out pam_keyinit in the /etc/pam.d files and
running the following program a couple of times in a row:

	#include <stdio.h>
	#include <stdlib.h>
	#include <keyutils.h>
	int main(int argc, char *argv[])
	{
		key_serial_t uk, usk, sk, nsk;
		uk  = keyctl_get_keyring_ID(KEY_SPEC_USER_KEYRING, 0);
		usk = keyctl_get_keyring_ID(KEY_SPEC_USER_SESSION_KEYRING, 0);
		sk  = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0);
		nsk = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 1);
		printf("keys: %08x %08x %08x %08x\n", uk, usk, sk, nsk);
		return 0;
	}

Without this patch, I see:

	keys: 3975ddc7 119c0c66 119c0c66 119c0c66
	keys: 3975ddc7 119c0c66 119c0c66 119c0c66

With this patch, I see:

	keys: 2cb4997b 34112878 34112878 17db2ce3
	keys: 2cb4997b 34112878 34112878 39f3c73e

As can be seen, the session keyring starts off the same as the user-session
keyring each time, but with the patch a new session keyring is created when
the create flag is set.
Reported-by: NGreg Wettstein <greg@enjellic.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NGreg Wettstein <greg@enjellic.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

If install_session_keyring() is given a keyring, it should install it rather
than just creating a new one anyway.  This was accidentally broken in:

	commit d84f4f99
	Author: David Howells <dhowells@redhat.com>
	Date:   Fri Nov 14 10:39:23 2008 +1100
	Subject: CRED: Inaugurate COW credentials

The impact of that commit is that pam_keyinit no longer works correctly if
'force' isn't specified against a login process. This is because:

	keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0)

now always creates a new session keyring and thus the check whether the session
keyring and the user-session keyring are the same is always false.  This leads
pam_keyinit to conclude that a session keyring is installed and it shouldn't be
revoked by pam_keyinit here if 'revoke' is specified.

Any system that specifies 'force' against pam_keyinit in the PAM configuration
files for login methods (login, ssh, su -l, kdm, etc.) is not affected since
that bypasses the broken check and forces the creation of a new session keyring
anyway (for which the revoke flag is not cleared) - and any subsequent call to
pam_keyinit really does have a session keyring already installed, and so the
check works correctly there.

Reverting to the previous behaviour will cause the kernel to subscribe the
process to the user-session keyring as its session keyring if it doesn't have a
session keyring of its own.  pam_keyinit will detect this and install a new
session keyring anyway (and won't clear the revert flag).

This can be tested by commenting out pam_keyinit in the /etc/pam.d files and
running the following program a couple of times in a row:

	#include <stdio.h>
	#include <stdlib.h>
	#include <keyutils.h>
	int main(int argc, char *argv[])
	{
		key_serial_t uk, usk, sk;
		uk = keyctl_get_keyring_ID(KEY_SPEC_USER_KEYRING, 0);
		usk = keyctl_get_keyring_ID(KEY_SPEC_USER_SESSION_KEYRING, 0);
		sk = keyctl_get_keyring_ID(KEY_SPEC_SESSION_KEYRING, 0);
		printf("keys: %08x %08x %08x\n", uk, usk, sk);
		return 0;
	}

Without the patch, I see:

	keys: 3884e281 24c4dfcf 22825f8e
	keys: 3884e281 24c4dfcf 068772be

With the patch, I see:

	keys: 26be9c83 0e755ce0 0e755ce0
	keys: 26be9c83 0e755ce0 0e755ce0

As can be seen, with the patch, the session keyring is the same as the
user-session keyring each time; without the patch a new session keyring is
generated each time.
Reported-by: NGreg Wettstein <greg@enjellic.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NGreg Wettstein <greg@enjellic.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Update the MAINTAINERS file with an entry for EVM.
Reported-by: NRandy Dunlap <rdunlap@xenotimenet>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Although the EVM encrypted-key should be encrypted/decrypted using a
trusted-key, a user-defined key could be used instead. When using a user-
defined key, a TCG_TPM dependency should not be required.  Unfortunately,
the encrypted-key code needs to be refactored a bit in order to remove
this dependency.

This patch adds the TCG_TPM dependency.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>,
	     Randy Dunlap <rdunlap@xenotimenet>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

daemonize() is only needed when a user-space task does kernel_thread().

tomoyo_gc_thread() is kthread_create()'ed and thus it doesn't need
the soon-to-be-deprecated daemonize().
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NTejun Heo <tj@kernel.org>
Acked-by: NMatt Fleming <matt.fleming@intel.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

- Make the previously missing security_old_inode_init_security() stub
  function definition static inline.

- The stub security_inode_init_security() function previously returned
  -EOPNOTSUPP and relied on the callers to change it to 0.  The stub
  security/security_old_inode_init_security() functions now return 0.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Initialize has_cap in cap_bprm_set_creds()
Reported-by: NAndrew G. Morgan <morgan@kernel.org>
Signed-off-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

A task (when !SECURE_NOROOT) which executes a setuid-root binary will
obtain root privileges while executing that binary.  If the binary also
has effective capabilities set, then only those capabilities will be
granted.  The rationale is that the same binary can carry both setuid-root
and the minimal file capability set, so that on a filesystem not
supporting file caps the binary can still be executed with privilege,
while on a filesystem supporting file caps it will run with minimal
privilege.

This special case currently does NOT happen if there are file capabilities
but no effective capabilities.  Since capability-aware programs can very
well start with empty pE but populated pP and move those caps to pE when
needed.  In other words, if the file has file capabilities but NOT
effective capabilities, then we should do the same thing as if there
were file capabilities, and not grant full root privileges.

This patchset does that.

(Changelog by Serge Hallyn).
Signed-off-by: NZhi Li <lizhi1215@gmail.com>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Local XATTR_TRUSTED_PREFIX_LEN and XATTR_SECURITY_PREFIX_LEN definitions
redefined ones in 'linux/xattr.h'. This was caused by commit 9d8f13ba
("security: new security_inode_init_security API adds function callback")
including 'linux/xattr.h' in 'linux/security.h'.

In file included from include/linux/security.h:39,
                 from include/net/sock.h:54,
                 from fs/cifs/cifspdu.h:25,
                 from fs/cifs/xattr.c:26:

This patch removes the local definitions.
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

evm_inode_init_security() should return 0, when EVM is not enabled.
(Returning an error is a remnant of evm_inode_post_init_security.)
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

- Missing 'inline' on evm_inode_setattr() definition.
Introduced by commit 817b54aa ("evm: add evm_inode_setattr to prevent
updating an invalid security.evm").

- Missing security_old_inode_init_security() stub function definition.
Caused by commit 9d8f13ba ("security: new security_inode_init_security
API adds function callback").
Reported-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NMimi Zohar <zohar@us.ibm.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Select trusted and encrypted keys if EVM is selected, to ensure
the requisite symbols are available.  Otherwise, these can be
selected as modules while EVM is static, leading to a kernel
build failure.
Signed-off-by: NJames Morris <jmorris@namei.org>

Conflicts:
	fs/attr.c

Resolve conflict manually.
Signed-off-by: NJames Morris <jmorris@namei.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Fix build with DEBUG_PAGEALLOC enabled.

Commit d006199e72a9 ("serial: sh-sci: Regtype probing doesn't need to be
fatal.") made sci_init_single() return when sci_probe_regmap() succeeds,
although it should return when sci_probe_regmap() fails.  This causes
systems using the serial sh-sci driver to crash during boot.

Fix the problem by using the right return condition.
Signed-off-by: NRafael J. Wysocki <rjw@sisk.pl>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The generic library code already exports the generic function, this was
left-over from the ARM-specific version that just got removed.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Since commit 1eb19a12 ("lib/sha1: use the git implementation of
SHA-1"), the ARM SHA1 routines no longer work.  The reason? They
depended on the larger 320-byte workspace, and now the sha1 workspace is
just 16 words (64 bytes).  So the assembly version would overwrite the
stack randomly.

The optimized asm version is also probably slower than the new improved
C version, so there's no reason to keep it around.  At least that was
the case in git, where what appears to be the same assembly language
version was removed two years ago because the optimized C BLK_SHA1 code
was faster.
Reported-and-tested-by: NJoachim Eastwood <manabian@gmail.com>
Cc: Andreas Schwab <schwab@linux-m68k.org>
Cc: Nicolas Pitre <nico@fluxnic.net>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

task->cred is declared as __rcu, and access to other tasks' ->cred is,
indeed, protected.  Access to current->cred does not need rcu_dereference()
at all, since only the task itself can change its ->cred.  sparse, of
course, has no way of knowing that...

Add force-cast in current_cred(), make current_fsuid() et.al. use it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Al points out that the do_follow_link() helper function really is
misnamed - it's about whether we should try to follow a symlink or not,
not about actually doing the following.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

After commit 3567866b: "RCUify freeing acls, let check_acl() go ahead in
RCU mode if acl is cached" posix_acl_permission is being called with an
unsupported flag and the permission check fails. This patch fixes the issue.
Signed-off-by: NAri Savolainen <ari.m.savolainen@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

* 'for-linus' of git://git.open-osd.org/linux-open-osd:
  ore: Make ore its own module
  exofs: Rename raid engine from exofs/ios.c => ore
  exofs: ios: Move to a per inode components & device-table
  exofs: Move exofs specific osd operations out of ios.c
  exofs: Add offset/length to exofs_get_io_state
  exofs: Fix truncate for the raid-groups case
  exofs: Small cleanup of exofs_fill_super
  exofs: BUG: Avoid sbi realloc
  exofs: Remove pnfs-osd private definitions
  nfs_xdr: Move nfs4_string definition out of #ifdef CONFIG_NFS_V4

The inode structure layout is largely random, and some of the vfs paths
really do care.  The path lookup in particular is already quite D$
intensive, and profiles show that accessing the 'inode->i_op->xyz'
fields is quite costly.

We already optimized the dcache to not unnecessarily load the d_op
structure for members that are often NULL using the DCACHE_OP_xyz bits
in dentry->d_flags, and this does something very similar for the inode
ops that are used during pathname lookup.

It also re-orders the fields so that the fields accessed by 'stat' are
together at the beginning of the inode structure, and roughly in the
order accessed.

The effect of this seems to be in the 1-2% range for an empty kernel
"make -j" run (which is fairly kernel-intensive, mostly in filename
lookup), so it's visible.  The numbers are fairly noisy, though, and
likely depend a lot on exact microarchitecture.  So there's more tuning
to be done.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Gcc tends to generate better code with small integers, including the
DCACHE_xyz flag tests - so move the common ones to be first in the list.
Also just remove the unused DCACHE_INOTIFY_PARENT_WATCHED and
DCACHE_AUTOFS_PENDING values, their users no longer exists in the source
tree.

And add a "unlikely()" to the DCACHE_OP_COMPARE test, since we want the
common case to be a nice straight-line fall-through.
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net:
  net: Compute protocol sequence numbers and fragment IDs using MD5.
  crypto: Move md5_transform to lib/md5.c

Export everything from ore need exporting. Change Kbuild and Kconfig
to build ore.ko as an independent module. Import ore from exofs
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

ORE stands for "Objects Raid Engine"

This patch is a mechanical rename of everything that was in ios.c
and its API declaration to an ore.c and an osd_ore.h header. The ore
engine will later be used by the pnfs objects layout driver.

* File ios.c => ore.c

* Declaration of types and API are moved from exofs.h to a new
  osd_ore.h

* All used types are prefixed by ore_ from their exofs_ name.

* Shift includes from exofs.h to osd_ore.h so osd_ore.h is
  independent, include it from exofs.h.

Other than a pure rename there are no other changes. Next patch
will move the ore into it's own module and will export the API
to be used by exofs and later the layout driver
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

Exofs raid engine was saving on memory space by having a single layout-info,
single pid, and a single device-table, global to the filesystem. Then passing
a credential and object_id info at the io_state level, private for each
inode. It would also devise this contraption of rotating the device table
view for each inode->ino to spread out the device usage.

This is not compatible with the pnfs-objects standard, demanding that
each inode can have it's own layout-info, device-table, and each object
component it's own pid, oid and creds.

So: Bring exofs raid engine to be usable for generic pnfs-objects use by:

* Define an exofs_comp structure that holds obj_id and credential info.

* Break up exofs_layout struct to an exofs_components structure that holds a
  possible array of exofs_comp and the array of devices + the size of the
  arrays.

* Add a "comps" parameter to get_io_state() that specifies the ids creds
  and device array to use for each IO.

  This enables to keep the layout global, but the device-table view, creds
  and IDs at the inode level. It only adds two 64bit to each inode, since
  some of these members already existed in another form.

* ios raid engine now access layout-info and comps-info through the passed
  pointers. Everything is pre-prepared by caller for generic access of
  these structures and arrays.

At the exofs Level:

* Super block holds an exofs_components struct that holds the device
  array, previously in layout. The devices there are in device-table
  order. The device-array is twice bigger and repeats the device-table
  twice so now each inode's device array can point to a random device
  and have a round-robin view of the table, making it compatible to
  previous exofs versions.

* Each inode has an exofs_components struct that is initialized at
  load time, with it's own view of the device table IDs and creds.
  When doing IO this gets passed to the io_state together with the
  layout.

While preforming this change. Bugs where found where credentials with the
wrong IDs where used to access the different SB objects (super.c). As well
as some dead code. It was never noticed because the target we use does not
check the credentials.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

ios.c will be moving to an external library, for use by the
objects-layout-driver. Remove from it some exofs specific functions.

Also g_attr_logical_length is used both by inode.c and ios.c
move definition to the later, to keep it independent
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

In future raid code we will need to know the IO offset/length
and if it's a read or write to determine some of the array
sizes we'll need.

So add a new exofs_get_rw_state() API for use when
writeing/reading. All other simple cases are left using the
old way.

The major change to this is that now we need to call
exofs_get_io_state later at inode.c::read_exec and
inode.c::write_exec when we actually know these things. So this
patch is kept separate so I can test things apart from other
changes.
Signed-off-by: NBoaz Harrosh <bharrosh@panasas.com>

Computers have become a lot faster since we compromised on the
partial MD4 hash which we use currently for performance reasons.

MD5 is a much safer choice, and is inline with both RFC1948 and
other ISS generators (OpenBSD, Solaris, etc.)

Furthermore, only having 24-bits of the sequence number be truly
unpredictable is a very serious limitation.  So the periodic
regeneration and 8-bit counter have been removed.  We compute and
use a full 32-bit sequence number.

For ipv6, DCCP was found to use a 32-bit truncated initial sequence
number (it needs 43-bits) and that is fixed here as well.
Reported-by: NDan Kaminsky <dan@doxpara.com>
Tested-by: NWilly Tarreau <w@1wt.eu>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

We are going to use this for TCP/IP sequence number and fragment ID
generation.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>