When a key description argument is imported into the kernel from userspace, as
happens in add_key(), request_key(), KEYCTL_JOIN_SESSION_KEYRING,
KEYCTL_SEARCH, the description is copied into a buffer up to PAGE_SIZE in size.
PAGE_SIZE, however, is a variable quantity, depending on the arch.  Fix this at
4096 instead (ie. 4095 plus a NUL termination) and define a constant
(KEY_MAX_DESC_SIZE) to this end.

When reading the description back with KEYCTL_DESCRIBE, a PAGE_SIZE internal
buffer is allocated into which the information and description will be
rendered.  This means that the description will get truncated if an extremely
long description it has to be crammed into the buffer with the stringified
information.  There is no particular need to copy the description into the
buffer, so just copy it directly to userspace in a separate operation.
Reported-by: NChristian Kastner <debian@kvr.at>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NChristian Kastner <debian@kvr.at>

Reinstate the generation of EPERM for a key type name beginning with a '.' in
a userspace call.  Types whose name begins with a '.' are internal only.

The test was removed by:

	commit a4e3b8d7
	Author: Mimi Zohar <zohar@linux.vnet.ibm.com>
	Date:   Thu May 22 14:02:23 2014 -0400
	Subject: KEYS: special dot prefixed keyring name bug fix

I think we want to keep the restriction on type name so that userspace can't
add keys of a special internal type.

Note that removal of the test causes several of the tests in the keyutils
testsuite to fail.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NVivek Goyal <vgoyal@redhat.com>
cc: Mimi Zohar <zohar@linux.vnet.ibm.com>

Special kernel keys, such as those used to hold DNS results for AFS, CIFS and
NFS and those used to hold idmapper results for NFS, used to be
'invalidateable' with key_revoke().  However, since the default permissions for
keys were reduced:

	Commit: 96b5c8fe
	KEYS: Reduce initial permissions on keys

it has become impossible to do this.

Add a key flag (KEY_FLAG_ROOT_CAN_INVAL) that will permit a key to be
invalidated by root.  This should not be used for system keyrings as the
garbage collector will try and remove any invalidate key.  For system keyrings,
KEY_FLAG_ROOT_CAN_CLEAR can be used instead.

After this, from userspace, keyctl_invalidate() and "keyctl invalidate" can be
used by any possessor of CAP_SYS_ADMIN (typically root) to invalidate DNS and
idmapper keys.  Invalidated keys are immediately garbage collected and will be
immediately rerequested if needed again.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NSteve Dickson <steved@redhat.com>

Dot prefixed keyring names are supposed to be reserved for the
kernel, but add_key() calls key_get_type_from_user(), which
incorrectly verifies the 'type' field, not the 'description' field.
This patch verifies the 'description' field isn't dot prefixed,
when creating a new keyring, and removes the dot prefix test in
key_get_type_from_user().

Changelog v6:
- whitespace and other cleanup

Changelog v5:
- Only prevent userspace from creating a dot prefixed keyring, not
  regular keys  - Dmitry
Reported-by: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Acked-by: NDavid Howells <dhowells@redhat.com>

Move the flags representing required permission to linux/key.h as the perm
parameter of security_key_permission() is in terms of them - and not the
permissions mask flags used in key->perm.

Whilst we're at it:

 (1) Rename them to be KEY_NEED_xxx rather than KEY_xxx to avoid collisions
     with symbols in uapi/linux/input.h.

 (2) Don't use key_perm_t for a mask of required permissions, but rather limit
     it to the permissions mask attached to the key and arguments related
     directly to that.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NDmitry Kasatkin <d.kasatkin@samsung.com>

Add support for per-user_namespace registers of persistent per-UID kerberos
caches held within the kernel.

This allows the kerberos cache to be retained beyond the life of all a user's
processes so that the user's cron jobs can work.

The kerberos cache is envisioned as a keyring/key tree looking something like:

	struct user_namespace
	  \___ .krb_cache keyring		- The register
		\___ _krb.0 keyring		- Root's Kerberos cache
		\___ _krb.5000 keyring		- User 5000's Kerberos cache
		\___ _krb.5001 keyring		- User 5001's Kerberos cache
			\___ tkt785 big_key	- A ccache blob
			\___ tkt12345 big_key	- Another ccache blob

Or possibly:

	struct user_namespace
	  \___ .krb_cache keyring		- The register
		\___ _krb.0 keyring		- Root's Kerberos cache
		\___ _krb.5000 keyring		- User 5000's Kerberos cache
		\___ _krb.5001 keyring		- User 5001's Kerberos cache
			\___ tkt785 keyring	- A ccache
				\___ krbtgt/REDHAT.COM@REDHAT.COM big_key
				\___ http/REDHAT.COM@REDHAT.COM user
				\___ afs/REDHAT.COM@REDHAT.COM user
				\___ nfs/REDHAT.COM@REDHAT.COM user
				\___ krbtgt/KERNEL.ORG@KERNEL.ORG big_key
				\___ http/KERNEL.ORG@KERNEL.ORG big_key

What goes into a particular Kerberos cache is entirely up to userspace.  Kernel
support is limited to giving you the Kerberos cache keyring that you want.

The user asks for their Kerberos cache by:

	krb_cache = keyctl_get_krbcache(uid, dest_keyring);

The uid is -1 or the user's own UID for the user's own cache or the uid of some
other user's cache (requires CAP_SETUID).  This permits rpc.gssd or whatever to
mess with the cache.

The cache returned is a keyring named "_krb.<uid>" that the possessor can read,
search, clear, invalidate, unlink from and add links to.  Active LSMs get a
chance to rule on whether the caller is permitted to make a link.

Each uid's cache keyring is created when it first accessed and is given a
timeout that is extended each time this function is called so that the keyring
goes away after a while.  The timeout is configurable by sysctl but defaults to
three days.

Each user_namespace struct gets a lazily-created keyring that serves as the
register.  The cache keyrings are added to it.  This means that standard key
search and garbage collection facilities are available.

The user_namespace struct's register goes away when it does and anything left
in it is then automatically gc'd.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NSimo Sorce <simo@redhat.com>
cc: Serge E. Hallyn <serge.hallyn@ubuntu.com>
cc: Eric W. Biederman <ebiederm@xmission.com>

Faster kernel compiles by way of fewer unnecessary includes.

[akpm@linux-foundation.org: fix fallout]
[akpm@linux-foundation.org: fix build]
Signed-off-by: NKent Overstreet <koverstreet@google.com>
Cc: Zach Brown <zab@redhat.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Asai Thambi S P <asamymuthupa@micron.com>
Cc: Selvan Mani <smani@micron.com>
Cc: Sam Bradshaw <sbradshaw@micron.com>
Cc: Jeff Moyer <jmoyer@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Benjamin LaHaise <bcrl@kvack.org>
Reviewed-by: N"Theodore Ts'o" <tytso@mit.edu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Give the key type the opportunity to preparse the payload prior to the
instantiation and update routines being called.  This is done with the
provision of two new key type operations:

	int (*preparse)(struct key_preparsed_payload *prep);
	void (*free_preparse)(struct key_preparsed_payload *prep);

If the first operation is present, then it is called before key creation (in
the add/update case) or before the key semaphore is taken (in the update and
instantiate cases).  The second operation is called to clean up if the first
was called.

preparse() is given the opportunity to fill in the following structure:

	struct key_preparsed_payload {
		char		*description;
		void		*type_data[2];
		void		*payload;
		const void	*data;
		size_t		datalen;
		size_t		quotalen;
	};

Before the preparser is called, the first three fields will have been cleared,
the payload pointer and size will be stored in data and datalen and the default
quota size from the key_type struct will be stored into quotalen.

The preparser may parse the payload in any way it likes and may store data in
the type_data[] and payload fields for use by the instantiate() and update()
ops.

The preparser may also propose a description for the key by attaching it as a
string to the description field.  This can be used by passing a NULL or ""
description to the add_key() system call or the key_create_or_update()
function.  This cannot work with request_key() as that required the description
to tell the upcall about the key to be created.

This, for example permits keys that store PGP public keys to generate their own
name from the user ID and public key fingerprint in the key.

The instantiate() and update() operations are then modified to look like this:

	int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
	int (*update)(struct key *key, struct key_preparsed_payload *prep);

and the new payload data is passed in *prep, whether or not it was preparsed.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NRusty Russell <rusty@rustcorp.com.au>

Make the session keyring per-thread rather than per-process, but still
inherited from the parent thread to solve a problem with PAM and gdm.

The problem is that join_session_keyring() will reject attempts to change the
session keyring of a multithreaded program but gdm is now multithreaded before
it gets to the point of starting PAM and running pam_keyinit to create the
session keyring.  See:

	https://bugs.freedesktop.org/show_bug.cgi?id=49211

The reason that join_session_keyring() will only change the session keyring
under a single-threaded environment is that it's hard to alter the other
thread's credentials to effect the change in a multi-threaded program.  The
problems are such as:

 (1) How to prevent two threads both running join_session_keyring() from
     racing.

 (2) Another thread's credentials may not be modified directly by this process.

 (3) The number of threads is uncertain whilst we're not holding the
     appropriate spinlock, making preallocation slightly tricky.

 (4) We could use TIF_NOTIFY_RESUME and key_replace_session_keyring() to get
     another thread to replace its keyring, but that means preallocating for
     each thread.

A reasonable way around this is to make the session keyring per-thread rather
than per-process and just document that if you want a common session keyring,
you must get it before you spawn any threads - which is the current situation
anyway.

Whilst we're at it, we can the process keyring behave in the same way.  This
means we can clean up some of the ickyness in the creds code.

Basically, after this patch, the session, process and thread keyrings are about
inheritance rules only and not about sharing changes of keyring.
Reported-by: NMantas M. <grawity@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Tested-by: NRay Strode <rstrode@redhat.com>

On an error iov may still have been reallocated and need freeing
Signed-off-by: NAlan Cox <alan@linux.intel.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>

- Replace key_user ->user_ns equality checks with kuid_has_mapping checks.
- Use from_kuid to generate key descriptions
- Use kuid_t and kgid_t and the associated helpers instead of uid_t and gid_t
- Avoid potential problems with file descriptor passing by displaying
  keys in the user namespace of the opener of key status proc files.

Cc: linux-security-module@vger.kernel.org
Cc: keyrings@linux-nfs.org
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

This reverts commit d35abdb2.

task_lock() was added to ensure exit_mm() and thus exit_task_work() is
not possible before task_work_add().

This is wrong, task_lock() must not be nested with write_lock(tasklist).
And this is no longer needed, task_work_add() now fails if it is called
after exit_task_work().
Reported-by: NDave Jones <davej@redhat.com>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NPeter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20120826191214.GA4231@redhat.comSigned-off-by: NIngo Molnar <mingo@kernel.org>

Give the key type the opportunity to preparse the payload prior to the
instantiation and update routines being called.  This is done with the
provision of two new key type operations:

	int (*preparse)(struct key_preparsed_payload *prep);
	void (*free_preparse)(struct key_preparsed_payload *prep);

If the first operation is present, then it is called before key creation (in
the add/update case) or before the key semaphore is taken (in the update and
instantiate cases).  The second operation is called to clean up if the first
was called.

preparse() is given the opportunity to fill in the following structure:

	struct key_preparsed_payload {
		char		*description;
		void		*type_data[2];
		void		*payload;
		const void	*data;
		size_t		datalen;
		size_t		quotalen;
	};

Before the preparser is called, the first three fields will have been cleared,
the payload pointer and size will be stored in data and datalen and the default
quota size from the key_type struct will be stored into quotalen.

The preparser may parse the payload in any way it likes and may store data in
the type_data[] and payload fields for use by the instantiate() and update()
ops.

The preparser may also propose a description for the key by attaching it as a
string to the description field.  This can be used by passing a NULL or ""
description to the add_key() system call or the key_create_or_update()
function.  This cannot work with request_key() as that required the description
to tell the upcall about the key to be created.

This, for example permits keys that store PGP public keys to generate their own
name from the user ID and public key fingerprint in the key.

The instantiate() and update() operations are then modified to look like this:

	int (*instantiate)(struct key *key, struct key_preparsed_payload *prep);
	int (*update)(struct key *key, struct key_preparsed_payload *prep);

and the new payload data is passed in *prep, whether or not it was preparsed.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

task_work and rcu_head are identical now; merge them (calling the result
struct callback_head, rcu_head #define'd to it), kill separate allocation
in security/keys since we can just use cred->rcu now.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

get rid of the only user of ->data; this is _not_ the final variant - in the
end we'll have task_work and rcu_head identical and just use cred->rcu,
at which point the separate allocation will be gone completely.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

A cleanup of rw_copy_check_uvector and compat_rw_copy_check_uvector after
changes made to support CMA in an earlier patch.

Rather than having an additional check_access parameter to these
functions, the first paramater type is overloaded to allow the caller to
specify CHECK_IOVEC_ONLY which means check that the contents of the iovec
are valid, but do not check the memory that they point to.  This is used
by process_vm_readv/writev where we need to validate that a iovec passed
to the syscall is valid but do not want to check the memory that it points
to at this point because it refers to an address space in another process.
Signed-off-by: NChris Yeoh <yeohc@au1.ibm.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allocation may be large.  The code is probing to see if it will
succeed and if not, it falls back to vmalloc().  We should suppress any
page-allocation failure messages when the fallback happens.
Reported-by: NDave Jones <davej@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix some sparse warnings in the keyrings code:

 (1) compat_keyctl_instantiate_key_iov() should be static.

 (2) There were a couple of places where a pointer was being compared against
     integer 0 rather than NULL.

 (3) keyctl_instantiate_key_common() should not take a __user-labelled iovec
     pointer as the caller must have copied the iovec to kernel space.

 (4) __key_link_begin() takes and __key_link_end() releases
     keyring_serialise_link_sem under some circumstances and so this should be
     declared.

     Note that adding __acquires() and __releases() for this doesn't help cure
     the warnings messages - something only commenting out both helps.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

Change keyctl_session_to_parent() to use task_work_add() and move
key_replace_session_keyring() logic into task_work->func().

Note that we do task_work_cancel() before task_work_add() to ensure that
only one work can be pending at any time.  This is important, we must not
allow user-space to abuse the parent's ->task_works list.

The callback, replace_session_keyring(), checks PF_EXITING.  I guess this
is not really needed but looks better.

As a side effect, this fixes the (unlikely) race.  The callers of
key_replace_session_keyring() and keyctl_session_to_parent() lack the
necessary barriers, the parent can miss the request.

Now we can remove task_struct->replacement_session_keyring and related
code.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Richard Kuo <rkuo@codeaurora.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Alexander Gordeev <agordeev@redhat.com>
Cc: Chris Zankel <chris@zankel.net>
Cc: David Smith <dsmith@redhat.com>
Cc: "Frank Ch. Eigler" <fche@redhat.com>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Larry Woodman <lwoodman@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Tejun Heo <tj@kernel.org>
Cc: Ingo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add support for invalidating a key - which renders it immediately invisible to
further searches and causes the garbage collector to immediately wake up,
remove it from keyrings and then destroy it when it's no longer referenced.

It's better not to do this with keyctl_revoke() as that marks the key to start
returning -EKEYREVOKED to searches when what is actually desired is to have the
key refetched.

To invalidate a key the caller must be granted SEARCH permission by the key.
This may be too strict.  It may be better to also permit invalidation if the
caller has any of READ, WRITE or SETATTR permission.

The primary use for this is to evict keys that are cached in special keyrings,
such as the DNS resolver or an ID mapper.
Signed-off-by: NDavid Howells <dhowells@redhat.com>

The keyctl_set_timeout function isn't exported to other parts of the
kernel, but I want to use it for the NFS idmapper.  I already have the
key, but I wanted a generic way to set the timeout.
Signed-off-by: NBryan Schumaker <bjschuma@netapp.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

The kernel contains some special internal keyrings, for instance the DNS
resolver keyring :

2a93faf1 I-----     1 perm 1f030000     0     0 keyring   .dns_resolver: empty

It would occasionally be useful to allow the contents of such keyrings to be
flushed by root (cache invalidation).

Allow a flag to be set on a keyring to mark that someone possessing the
sysadmin capability can clear the keyring, even without normal write access to
the keyring.

Set this flag on the special keyrings created by the DNS resolver, the NFS
identity mapper and the CIFS identity mapper.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NJeff Layton <jlayton@redhat.com>
Acked-by: NSteve Dickson <steved@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

The basic idea behind cross memory attach is to allow MPI programs doing
intra-node communication to do a single copy of the message rather than a
double copy of the message via shared memory.

The following patch attempts to achieve this by allowing a destination
process, given an address and size from a source process, to copy memory
directly from the source process into its own address space via a system
call.  There is also a symmetrical ability to copy from the current
process's address space into a destination process's address space.

- Use of /proc/pid/mem has been considered, but there are issues with
  using it:
  - Does not allow for specifying iovecs for both src and dest, assuming
    preadv or pwritev was implemented either the area read from or
  written to would need to be contiguous.
  - Currently mem_read allows only processes who are currently
  ptrace'ing the target and are still able to ptrace the target to read
  from the target. This check could possibly be moved to the open call,
  but its not clear exactly what race this restriction is stopping
  (reason  appears to have been lost)
  - Having to send the fd of /proc/self/mem via SCM_RIGHTS on unix
  domain socket is a bit ugly from a userspace point of view,
  especially when you may have hundreds if not (eventually) thousands
  of processes  that all need to do this with each other
  - Doesn't allow for some future use of the interface we would like to
  consider adding in the future (see below)
  - Interestingly reading from /proc/pid/mem currently actually
  involves two copies! (But this could be fixed pretty easily)

As mentioned previously use of vmsplice instead was considered, but has
problems.  Since you need the reader and writer working co-operatively if
the pipe is not drained then you block.  Which requires some wrapping to
do non blocking on the send side or polling on the receive.  In all to all
communication it requires ordering otherwise you can deadlock.  And in the
example of many MPI tasks writing to one MPI task vmsplice serialises the
copying.

There are some cases of MPI collectives where even a single copy interface
does not get us the performance gain we could.  For example in an
MPI_Reduce rather than copy the data from the source we would like to
instead use it directly in a mathops (say the reduce is doing a sum) as
this would save us doing a copy.  We don't need to keep a copy of the data
from the source.  I haven't implemented this, but I think this interface
could in the future do all this through the use of the flags - eg could
specify the math operation and type and the kernel rather than just
copying the data would apply the specified operation between the source
and destination and store it in the destination.

Although we don't have a "second user" of the interface (though I've had
some nibbles from people who may be interested in using it for intra
process messaging which is not MPI).  This interface is something which
hardware vendors are already doing for their custom drivers to implement
fast local communication.  And so in addition to this being useful for
OpenMPI it would mean the driver maintainers don't have to fix things up
when the mm changes.

There was some discussion about how much faster a true zero copy would
go. Here's a link back to the email with some testing I did on that:

http://marc.info/?l=linux-mm&m=130105930902915&w=2

There is a basic man page for the proposed interface here:

http://ozlabs.org/~cyeoh/cma/process_vm_readv.txt

This has been implemented for x86 and powerpc, other architecture should
mainly (I think) just need to add syscall numbers for the process_vm_readv
and process_vm_writev. There are 32 bit compatibility versions for
64-bit kernels.

For arch maintainers there are some simple tests to be able to quickly
verify that the syscalls are working correctly here:

http://ozlabs.org/~cyeoh/cma/cma-test-20110718.tgzSigned-off-by: NChris Yeoh <yeohc@au1.ibm.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Cc: <linux-man@vger.kernel.org>
Cc: <linux-arch@vger.kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make request_key() and co. return an error for a negative or rejected key.  If
the key was simply negated, then return ENOKEY, otherwise return the error
with which it was rejected.

Without this patch, the following command returns a key number (with the latest
keyutils):

	[root@andromeda ~]# keyctl request2 user debug:foo rejected @s
	586569904

Trying to print the key merely gets you a permission denied error:

	[root@andromeda ~]# keyctl print 586569904
	keyctl_read_alloc: Permission denied

Doing another request_key() call does get you the error, as long as it hasn't
expired yet:

	[root@andromeda ~]# keyctl request user debug:foo
	request_key: Key was rejected by service
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Add a keyctl op (KEYCTL_INSTANTIATE_IOV) that is like KEYCTL_INSTANTIATE, but
takes an iovec array and concatenates the data in-kernel into one buffer.
Since the KEYCTL_INSTANTIATE copies the data anyway, this isn't too much of a
problem.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Add a new keyctl op to reject a key with a specified error code.  This works
much the same as negating a key, and so keyctl_negate_key() is made a special
case of keyctl_reject_key().  The difference is that keyctl_negate_key()
selects ENOKEY as the error to be reported.

Typically the key would be rejected with EKEYEXPIRED, EKEYREVOKED or
EKEYREJECTED, but this is not mandatory.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix up comments in the key management code.  No functional changes.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Do a bit of a style clean up in the key management code.  No functional
changes.

Done using:

  perl -p -i -e 's!^/[*]*/\n!!' security/keys/*.c
  perl -p -i -e 's!} /[*] end [a-z0-9_]*[(][)] [*]/\n!}\n!' security/keys/*.c
  sed -i -s -e ": next" -e N -e 's/^\n[}]$/}/' -e t -e P -e 's/^.*\n//' -e "b next" security/keys/*.c

To remove /*****/ lines, remove comments on the closing brace of a
function to name the function and remove blank lines before the closing
brace of a function.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Fix a bug in keyctl_session_to_parent() whereby it tries to check the ownership
of the parent process's session keyring whether or not the parent has a session
keyring [CVE-2010-2960].

This results in the following oops:

  BUG: unable to handle kernel NULL pointer dereference at 00000000000000a0
  IP: [<ffffffff811ae4dd>] keyctl_session_to_parent+0x251/0x443
  ...
  Call Trace:
   [<ffffffff811ae2f3>] ? keyctl_session_to_parent+0x67/0x443
   [<ffffffff8109d286>] ? __do_fault+0x24b/0x3d0
   [<ffffffff811af98c>] sys_keyctl+0xb4/0xb8
   [<ffffffff81001eab>] system_call_fastpath+0x16/0x1b

if the parent process has no session keyring.

If the system is using pam_keyinit then it mostly protected against this as all
processes derived from a login will have inherited the session keyring created
by pam_keyinit during the log in procedure.

To test this, pam_keyinit calls need to be commented out in /etc/pam.d/.
Reported-by: NTavis Ormandy <taviso@cmpxchg8b.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NTavis Ormandy <taviso@cmpxchg8b.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There's an protected access to the parent process's credentials in the middle
of keyctl_session_to_parent().  This results in the following RCU warning:

  ===================================================
  [ INFO: suspicious rcu_dereference_check() usage. ]
  ---------------------------------------------------
  security/keys/keyctl.c:1291 invoked rcu_dereference_check() without protection!

  other info that might help us debug this:

  rcu_scheduler_active = 1, debug_locks = 0
  1 lock held by keyctl-session-/2137:
   #0:  (tasklist_lock){.+.+..}, at: [<ffffffff811ae2ec>] keyctl_session_to_parent+0x60/0x236

  stack backtrace:
  Pid: 2137, comm: keyctl-session- Not tainted 2.6.36-rc2-cachefs+ #1
  Call Trace:
   [<ffffffff8105606a>] lockdep_rcu_dereference+0xaa/0xb3
   [<ffffffff811ae379>] keyctl_session_to_parent+0xed/0x236
   [<ffffffff811af77e>] sys_keyctl+0xb4/0xb6
   [<ffffffff81001eab>] system_call_fastpath+0x16/0x1b

The code should take the RCU read lock to make sure the parents credentials
don't go away, even though it's holding a spinlock and has IRQ disabled.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

keyctl_describe_key() turns the key reference it gets into a usable key pointer
and assigns that to a variable called 'key', which it then ignores in favour of
recomputing the key pointer each time it needs it.  Make it use the precomputed
pointer instead.

Without this patch, gcc 4.6 reports that the variable key is set but not used:

	building with gcc 4.6 I'm getting a warning message:
	 CC      security/keys/keyctl.o
	security/keys/keyctl.c: In function 'keyctl_describe_key':
	security/keys/keyctl.c:472:14: warning: variable 'key' set but not used
Reported-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Authorise a process to perform keyctl_set_timeout() on an uninstantiated key if
that process has the authorisation key for it.

This allows the instantiator to set the timeout on a key it is instantiating -
provided it does it before instantiating the key.

For instance, the test upcall script provided with the keyutils package could
be modified to set the expiry to an hour hence before instantiating the key:

	[/usr/share/keyutils/request-key-debug.sh]
	 if [ "$3" != "neg" ]
	 then
	+    keyctl timeout $1 3600
	     keyctl instantiate $1 "Debug $3" $4 || exit 1
	 else
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

This is from a Smatch check I'm writing.

strncpy_from_user() returns -EFAULT on error so the first change just
silences a warning but doesn't change how the code works.

The other change is a bug fix because install_thread_keyring_to_cred()
can return a variety of errors such as -EINVAL, -EEXIST, -ENOMEM or
-EKEYREVOKED.
Signed-off-by: NDan Carpenter <error27@gmail.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

No functional changes.

keyctl_session_to_parent() is the only user of signal->count which needs
the correct value.  Change it to use thread_group_empty() instead, this
must be strictly equivalent under tasklist, and imho looks better.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Acked-by: NDavid Howells <dhowells@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Acked-by: NRoland McGrath <roland@redhat.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Whitespace coding style fixes.
Signed-off-by: NJustin P. Mattock <justinmattock@gmail.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Unused hook.  Remove.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

As of commit ee18d64c ("KEYS: Add a keyctl to
install a process's session keyring on its parent [try #6]"), CONFIG_KEYS=y
fails to build on architectures that haven't implemented TIF_NOTIFY_RESUME yet:

security/keys/keyctl.c: In function 'keyctl_session_to_parent':
security/keys/keyctl.c:1312: error: 'TIF_NOTIFY_RESUME' undeclared (first use in this function)
security/keys/keyctl.c:1312: error: (Each undeclared identifier is reported only once
security/keys/keyctl.c:1312: error: for each function it appears in.)

Make KEYCTL_SESSION_TO_PARENT depend on TIF_NOTIFY_RESUME until
m68k, and xtensa have implemented it.
Signed-off-by: NGeert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NMike Frysinger <vapier@gentoo.org>

Return the PTR_ERR of the correct pointer.
Signed-off-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Acked-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>