Commit Graph

107 Commits

Author SHA1 Message Date
David S. Miller
e33f770426 xfrm: Mark flowi arg to security_xfrm_state_pol_flow_match() const.
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-02-22 18:13:15 -08:00
Chris Wright
6037b715d6 security: add cred argument to security_capable()
Expand security_capable() to include cred, so that it can be usable in a
wider range of call sites.

Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2011-02-11 17:41:58 +11:00
Linus Torvalds
b4a45f5fe8 Merge branch 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin
* 'vfs-scale-working' of git://git.kernel.org/pub/scm/linux/kernel/git/npiggin/linux-npiggin: (57 commits)
  fs: scale mntget/mntput
  fs: rename vfsmount counter helpers
  fs: implement faster dentry memcmp
  fs: prefetch inode data in dcache lookup
  fs: improve scalability of pseudo filesystems
  fs: dcache per-inode inode alias locking
  fs: dcache per-bucket dcache hash locking
  bit_spinlock: add required includes
  kernel: add bl_list
  xfs: provide simple rcu-walk ACL implementation
  btrfs: provide simple rcu-walk ACL implementation
  ext2,3,4: provide simple rcu-walk ACL implementation
  fs: provide simple rcu-walk generic_check_acl implementation
  fs: provide rcu-walk aware permission i_ops
  fs: rcu-walk aware d_revalidate method
  fs: cache optimise dentry and inode for rcu-walk
  fs: dcache reduce branches in lookup path
  fs: dcache remove d_mounted
  fs: fs_struct use seqlock
  fs: rcu-walk for path lookup
  ...
2011-01-07 08:56:33 -08:00
Nick Piggin
31e6b01f41 fs: rcu-walk for path lookup
Perform common cases of path lookups without any stores or locking in the
ancestor dentry elements. This is called rcu-walk, as opposed to the current
algorithm which is a refcount based walk, or ref-walk.

This results in far fewer atomic operations on every path element,
significantly improving path lookup performance. It also avoids cacheline
bouncing on common dentries, significantly improving scalability.

The overall design is like this:
* LOOKUP_RCU is set in nd->flags, which distinguishes rcu-walk from ref-walk.
* Take the RCU lock for the entire path walk, starting with the acquiring
  of the starting path (eg. root/cwd/fd-path). So now dentry refcounts are
  not required for dentry persistence.
* synchronize_rcu is called when unregistering a filesystem, so we can
  access d_ops and i_ops during rcu-walk.
* Similarly take the vfsmount lock for the entire path walk. So now mnt
  refcounts are not required for persistence. Also we are free to perform mount
  lookups, and to assume dentry mount points and mount roots are stable up and
  down the path.
* Have a per-dentry seqlock to protect the dentry name, parent, and inode,
  so we can load this tuple atomically, and also check whether any of its
  members have changed.
* Dentry lookups (based on parent, candidate string tuple) recheck the parent
  sequence after the child is found in case anything changed in the parent
  during the path walk.
* inode is also RCU protected so we can load d_inode and use the inode for
  limited things.
* i_mode, i_uid, i_gid can be tested for exec permissions during path walk.
* i_op can be loaded.

When we reach the destination dentry, we lock it, recheck lookup sequence,
and increment its refcount and mountpoint refcount. RCU and vfsmount locks
are dropped. This is termed "dropping rcu-walk". If the dentry refcount does
not match, we can not drop rcu-walk gracefully at the current point in the
lokup, so instead return -ECHILD (for want of a better errno). This signals the
path walking code to re-do the entire lookup with a ref-walk.

Aside from the final dentry, there are other situations that may be encounted
where we cannot continue rcu-walk. In that case, we drop rcu-walk (ie. take
a reference on the last good dentry) and continue with a ref-walk. Again, if
we can drop rcu-walk gracefully, we return -ECHILD and do the whole lookup
using ref-walk. But it is very important that we can continue with ref-walk
for most cases, particularly to avoid the overhead of double lookups, and to
gain the scalability advantages on common path elements (like cwd and root).

The cases where rcu-walk cannot continue are:
* NULL dentry (ie. any uncached path element)
* parent with d_inode->i_op->permission or ACLs
* dentries with d_revalidate
* Following links

In future patches, permission checks and d_revalidate become rcu-walk aware. It
may be possible eventually to make following links rcu-walk aware.

Uncached path elements will always require dropping to ref-walk mode, at the
very least because i_mutex needs to be grabbed, and objects allocated.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:27 +11:00
David S. Miller
3610cda53f af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks.
unix_release() can asynchornously set socket->sk to NULL, and
it does so without holding the unix_state_lock() on "other"
during stream connects.

However, the reverse mapping, sk->sk_socket, is only transitioned
to NULL under the unix_state_lock().

Therefore make the security hooks follow the reverse mapping instead
of the forward mapping.

Reported-by: Jeremy Fitzhardinge <jeremy@goop.org>
Reported-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-01-05 15:38:53 -08:00
Eric Paris
12b3052c3e capabilities/syslog: open code cap_syslog logic to fix build failure
The addition of CONFIG_SECURITY_DMESG_RESTRICT resulted in a build
failure when CONFIG_PRINTK=n.  This is because the capabilities code
which used the new option was built even though the variable in question
didn't exist.

The patch here fixes this by moving the capabilities checks out of the
LSM and into the caller.  All (known) LSMs should have been calling the
capabilities hook already so it actually makes the code organization
better to eliminate the hook altogether.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-15 15:40:01 -08:00
Linus Torvalds
f9ba5375a8 Merge branch 'ima-memory-use-fixes'
* ima-memory-use-fixes:
  IMA: fix the ToMToU logic
  IMA: explicit IMA i_flag to remove global lock on inode_delete
  IMA: drop refcnt from ima_iint_cache since it isn't needed
  IMA: only allocate iint when needed
  IMA: move read counter into struct inode
  IMA: use i_writecount rather than a private counter
  IMA: use inode->i_lock to protect read and write counters
  IMA: convert internal flags from long to char
  IMA: use unsigned int instead of long for counters
  IMA: drop the inode opencount since it isn't needed for operation
  IMA: use rbtree instead of radix tree for inode information cache
2010-10-26 11:37:48 -07:00
Eric Paris
bc7d2a3e66 IMA: only allocate iint when needed
IMA always allocates an integrity structure to hold information about
every inode, but only needed this structure to track the number of
readers and writers currently accessing a given inode.  Since that
information was moved into struct inode instead of the integrity struct
this patch stops allocating the integrity stucture until it is needed.
Thus greatly reducing memory usage.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-10-26 11:37:18 -07:00
Eric Paris
2606fd1fa5 secmark: make secmark object handling generic
Right now secmark has lots of direct selinux calls.  Use all LSM calls and
remove all SELinux specific knowledge.  The only SELinux specific knowledge
we leave is the mode.  The only point is to make sure that other LSMs at
least test this generic code before they assume it works.  (They may also
have to make changes if they do not represent labels as strings)

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Paul Moore <paul.moore@hp.com>
Acked-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:48 +11:00
KOSAKI Motohiro
b0ae198113 security: remove unused parameter from security_task_setscheduler()
All security modules shouldn't change sched_param parameter of
security_task_setscheduler().  This is not only meaningless, but also
make a harmful result if caller pass a static variable.

This patch remove policy and sched_param parameter from
security_task_setscheduler() becuase none of security module is
using it.

Cc: James Morris <jmorris@namei.org>
Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:44 +11:00
Tetsuo Handa
065d78a060 LSM: Fix security_module_enable() error.
We can set default LSM module to DAC (which means "enable no LSM module").
If default LSM module was set to DAC, security_module_enable() must return 0
unless overridden via boot time parameter.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Serge E. Hallyn <serge@hallyn.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:34 +11:00
Linus Torvalds
b34d8915c4 Merge branch 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux
* 'writable_limits' of git://decibel.fi.muni.cz/~xslaby/linux:
  unistd: add __NR_prlimit64 syscall numbers
  rlimits: implement prlimit64 syscall
  rlimits: switch more rlimit syscalls to do_prlimit
  rlimits: redo do_setrlimit to more generic do_prlimit
  rlimits: add rlimit64 structure
  rlimits: do security check under task_lock
  rlimits: allow setrlimit to non-current tasks
  rlimits: split sys_setrlimit
  rlimits: selinux, do rlimits changes under task_lock
  rlimits: make sure ->rlim_max never grows in sys_setrlimit
  rlimits: add task_struct to update_rlimit_cpu
  rlimits: security, add task_struct to setrlimit

Fix up various system call number conflicts.  We not only added fanotify
system calls in the meantime, but asm-generic/unistd.h added a wait4
along with a range of reserved per-architecture system calls.
2010-08-10 12:07:51 -07:00
Linus Torvalds
8c8946f509 Merge branch 'for-linus' of git://git.infradead.org/users/eparis/notify
* 'for-linus' of git://git.infradead.org/users/eparis/notify: (132 commits)
  fanotify: use both marks when possible
  fsnotify: pass both the vfsmount mark and inode mark
  fsnotify: walk the inode and vfsmount lists simultaneously
  fsnotify: rework ignored mark flushing
  fsnotify: remove global fsnotify groups lists
  fsnotify: remove group->mask
  fsnotify: remove the global masks
  fsnotify: cleanup should_send_event
  fanotify: use the mark in handler functions
  audit: use the mark in handler functions
  dnotify: use the mark in handler functions
  inotify: use the mark in handler functions
  fsnotify: send fsnotify_mark to groups in event handling functions
  fsnotify: Exchange list heads instead of moving elements
  fsnotify: srcu to protect read side of inode and vfsmount locks
  fsnotify: use an explicit flag to indicate fsnotify_destroy_mark has been called
  fsnotify: use _rcu functions for mark list traversal
  fsnotify: place marks on object in order of group memory address
  vfs/fsnotify: fsnotify_close can delay the final work in fput
  fsnotify: store struct file not struct path
  ...

Fix up trivial delete/modify conflict in fs/notify/inotify/inotify.c.
2010-08-10 11:39:13 -07:00
Tetsuo Handa
ea0d3ab239 LSM: Remove unused arguments from security_path_truncate().
When commit be6d3e56a6 "introduce new LSM hooks
where vfsmount is available." was proposed, regarding security_path_truncate(),
only "struct file *" argument (which AppArmor wanted to use) was removed.
But length and time_attrs arguments are not used by TOMOYO nor AppArmor.
Thus, let's remove these arguments.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: Nick Piggin <npiggin@suse.de>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:33:40 +10:00
Eric Paris
c4ec54b40d fsnotify: new fsnotify hooks and events types for access decisions
introduce a new fsnotify hook, fsnotify_perm(), which is called from the
security code.  This hook is used to allow fsnotify groups to make access
control decisions about events on the system.  We also must change the
generic fsnotify function to return an error code if we intend these hooks
to be in any way useful.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-07-28 09:59:01 -04:00
Jiri Slaby
8fd00b4d70 rlimits: security, add task_struct to setrlimit
Add task_struct to task_setrlimit of security_operations to be able to set
rlimit of task other than current.

Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <jmorris@namei.org>
2010-07-16 09:48:45 +02:00
Tetsuo Handa
c80901f275 LSM: Add __init to fixup function.
register_security() became __init function.
So do verify() and security_fixup_ops().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2010-05-17 09:27:20 +10:00
Eric Paris
05b90496f2 security: remove dead hook acct
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:19:19 +10:00
Eric Paris
3011a344cd security: remove dead hook key_session_to_parent
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:19:18 +10:00
Eric Paris
6307f8fee2 security: remove dead hook task_setgroups
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:19:18 +10:00
Eric Paris
06ad187e28 security: remove dead hook task_setgid
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:19:17 +10:00
Eric Paris
43ed8c3b45 security: remove dead hook task_setuid
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:19:16 +10:00
Eric Paris
0968d0060a security: remove dead hook cred_commit
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:19:15 +10:00
Eric Paris
9d5ed77dad security: remove dead hook inode_delete
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:19:15 +10:00
Eric Paris
91a9420f58 security: remove dead hook sb_post_pivotroot
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:18:32 +10:00
Eric Paris
3db2910177 security: remove dead hook sb_post_addmount
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:18:31 +10:00
Eric Paris
82dab10453 security: remove dead hook sb_post_remount
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:18:30 +10:00
Eric Paris
4b61d12c84 security: remove dead hook sb_umount_busy
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:18:30 +10:00
Eric Paris
231923bd0e security: remove dead hook sb_umount_close
Unused hook.  Remove.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:18:29 +10:00
Eric Paris
353633100d security: remove sb_check_sb hooks
Unused hook.  Remove it.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-04-12 12:18:28 +10:00
James Morris
c43a752347 Merge branch 'next-queue' into next 2010-03-09 12:46:47 +11:00
wzt.wzt@gmail.com
c1e992b996 Security: Add __init to register_security to disable load a security module on runtime
LSM framework doesn't allow to load a security module on runtime, it must be loaded on boot time.
but in security/security.c:
int register_security(struct security_operations *ops)
{
        ...
        if (security_ops != &default_security_ops)
                return -EAGAIN;
        ...
}
if security_ops == &default_security_ops, it can access to register a security module. If selinux is enabled,
other security modules can't register, but if selinux is disabled on boot time, the security_ops was set to
default_security_ops, LSM allows other kernel modules to use register_security() to register a not trust
security module. For example:

disable selinux on boot time(selinux=0).

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/version.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/security.h>

MODULE_LICENSE("GPL");
MODULE_AUTHOR("wzt");

extern int register_security(struct security_operations *ops);
int (*new_register_security)(struct security_operations *ops);

int rootkit_bprm_check_security(struct linux_binprm *bprm)
{
        return 0;
}

struct security_operations rootkit_ops = {
                .bprm_check_security = rootkit_bprm_check_security,
};

static int rootkit_init(void)
{
        printk("Load LSM rootkit module.\n");

	/* cat /proc/kallsyms | grep register_security */
        new_register_security = 0xc0756689;
        if (new_register_security(&rootkit_ops)) {
                printk("Can't register rootkit module.\n");
                return 0;
        }
        printk("Register rootkit module ok.\n");

        return 0;
}

static void rootkit_exit(void)
{
        printk("Unload LSM rootkit module.\n");
}

module_init(rootkit_init);
module_exit(rootkit_exit);

Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-03-03 09:15:28 +11:00
James Morris
b4ccebdd37 Merge branch 'next' into for-linus 2010-03-01 09:36:31 +11:00
wzt.wzt@gmail.com
189b3b1c89 Security: add static to security_ops and default_security_ops variable
Enhance the security framework to support resetting the active security
module. This eliminates the need for direct use of the security_ops and
default_security_ops variables outside of security.c, so make security_ops
and default_security_ops static. Also remove the secondary_ops variable as
a cleanup since there is no use for that. secondary_ops was originally used by
SELinux to call the "secondary" security module (capability or dummy),
but that was replaced by direct calls to capability and the only
remaining use is to save and restore the original security ops pointer
value if SELinux is disabled by early userspace based on /etc/selinux/config.
Further, if we support this directly in the security framework, then we can
just use &default_security_ops for this purpose since that is now available.

Signed-off-by: Zhitong Wang <zhitong.wangzt@alibaba-inc.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2010-02-24 08:11:02 +11:00
Al Viro
89068c576b Take ima_file_free() to proper place.
Hooks: Just Say No.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-02-07 03:07:29 -05:00
Kees Cook
002345925e syslog: distinguish between /proc/kmsg and syscalls
This allows the LSM to distinguish between syslog functions originating
from /proc/kmsg access and direct syscalls.  By default, the commoncaps
will now no longer require CAP_SYS_ADMIN to read an opened /proc/kmsg
file descriptor.  For example the kernel syslog reader can now drop
privileges after opening /proc/kmsg, instead of staying privileged with
CAP_SYS_ADMIN.  MAC systems that implement security_syslog have unchanged
behavior.

Signed-off-by: Kees Cook <kees.cook@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-02-04 14:20:12 +11:00
James Morris
8d9525048c security: correct error returns for get/set security with private inodes
Currently, the getsecurity and setsecurity operations return zero for
kernel private inodes, where xattrs are not available directly to
userspace.

This confuses some applications, and does not conform to the
man page for getxattr(2) etc., which state that these syscalls
should return ENOTSUP if xattrs are not supported or disabled.

Note that in the listsecurity case, we still need to return zero
as we don't know which other xattr handlers may be active.

For discussion of userland confusion, see:
http://www.mail-archive.com/bug-coreutils@gnu.org/msg17988.html

This patch corrects the error returns so that ENOTSUP is reported
to userspace as required.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: Serge Hallyn <serue@us.ibm.com>
2010-01-15 08:23:57 +11:00
Tetsuo Handa
5d0901a3a0 LSM: Rename security_path_ functions argument names.
include/linux/security.h and security/capability.c are using "struct path *dir"
but security/security.c was using "struct path *path" by error.
This patch renames "struct path *path" to "struct path *dir".

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-12-08 14:58:00 +11:00
Eric Paris
dd8dbf2e68 security: report the module name to security_module_request
For SELinux to do better filtering in userspace we send the name of the
module along with the AVC denial when a program is denied module_request.

Example output:

type=SYSCALL msg=audit(11/03/2009 10:59:43.510:9) : arch=x86_64 syscall=write success=yes exit=2 a0=3 a1=7fc28c0d56c0 a2=2 a3=7fffca0d7440 items=0 ppid=1727 pid=1729 auid=unset uid=root gid=root euid=root suid=root fsuid=root egid=root sgid=root fsgid=root tty=(none) ses=unset comm=rpc.nfsd exe=/usr/sbin/rpc.nfsd subj=system_u:system_r:nfsd_t:s0 key=(null)
type=AVC msg=audit(11/03/2009 10:59:43.510:9) : avc:  denied  { module_request } for  pid=1729 comm=rpc.nfsd kmod="net-pf-10" scontext=system_u:system_r:nfsd_t:s0 tcontext=system_u:system_r:kernel_t:s0 tclass=system

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-11-10 09:33:46 +11:00
John Johansen
6e65f92ff0 Config option to set a default LSM
The LSM currently requires setting a kernel parameter at boot to select
a specific LSM.  This adds a config option that allows specifying a default
LSM that is used unless overridden with the security= kernel parameter.
If the the config option is not set the current behavior of first LSM
to register is used.

Signed-off-by: John Johansen <john.johansen@canonical.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-11-09 08:40:07 +11:00
Mimi Zohar
6c21a7fb49 LSM: imbed ima calls in the security hooks
Based on discussions on LKML and LSM, where there are consecutive
security_ and ima_ calls in the vfs layer, move the ima_ calls to
the existing security_ hooks.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-10-25 12:22:48 +08:00
Tetsuo Handa
8b8efb4403 LSM: Add security_path_chroot().
This patch allows pathname based LSM modules to check chroot() operations.

This hook is used by TOMOYO.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-10-12 10:56:02 +11:00
Tetsuo Handa
89eda06837 LSM: Add security_path_chmod() and security_path_chown().
This patch allows pathname based LSM modules to check chmod()/chown()
operations. Since notify_change() does not receive "struct vfsmount *",
we add security_path_chmod() and security_path_chown() to the caller of
notify_change().

These hooks are used by TOMOYO.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: James Morris <jmorris@namei.org>
2009-10-12 10:56:00 +11:00
David P. Quigley
1ee65e37e9 LSM/SELinux: inode_{get,set,notify}secctx hooks to access LSM security context information.
This patch introduces three new hooks. The inode_getsecctx hook is used to get
all relevant information from an LSM about an inode. The inode_setsecctx is
used to set both the in-core and on-disk state for the inode based on a context
derived from inode_getsecctx.The final hook inode_notifysecctx will notify the
LSM of a change for the in-core state of the inode in question. These hooks are
for use in the labeled NFS code and addresses concerns of how to set security
on an inode in a multi-xattr LSM. For historical reasons Stephen Smalley's
explanation of the reason for these hooks is pasted below.

Quote Stephen Smalley

inode_setsecctx:  Change the security context of an inode.  Updates the
in core security context managed by the security module and invokes the
fs code as needed (via __vfs_setxattr_noperm) to update any backing
xattrs that represent the context.  Example usage:  NFS server invokes
this hook to change the security context in its incore inode and on the
backing file system to a value provided by the client on a SETATTR
operation.

inode_notifysecctx:  Notify the security module of what the security
context of an inode should be.  Initializes the incore security context
managed by the security module for this inode.  Example usage:  NFS
client invokes this hook to initialize the security context in its
incore inode to the value provided by the server for the file when the
server returned the file's attributes to the client.

Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-10 10:11:24 +10:00
David Howells
ee18d64c1f KEYS: Add a keyctl to install a process's session keyring on its parent [try #6]
Add a keyctl to install a process's session keyring onto its parent.  This
replaces the parent's session keyring.  Because the COW credential code does
not permit one process to change another process's credentials directly, the
change is deferred until userspace next starts executing again.  Normally this
will be after a wait*() syscall.

To support this, three new security hooks have been provided:
cred_alloc_blank() to allocate unset security creds, cred_transfer() to fill in
the blank security creds and key_session_to_parent() - which asks the LSM if
the process may replace its parent's session keyring.

The replacement may only happen if the process has the same ownership details
as its parent, and the process has LINK permission on the session keyring, and
the session keyring is owned by the process, and the LSM permits it.

Note that this requires alteration to each architecture's notify_resume path.
This has been done for all arches barring blackfin, m68k* and xtensa, all of
which need assembly alteration to support TIF_NOTIFY_RESUME.  This allows the
replacement to be performed at the point the parent process resumes userspace
execution.

This allows the userspace AFS pioctl emulation to fully emulate newpag() and
the VIOCSETTOK and VIOCSETTOK2 pioctls, all of which require the ability to
alter the parent process's PAG membership.  However, since kAFS doesn't use
PAGs per se, but rather dumps the keys into the session keyring, the session
keyring of the parent must be replaced if, for example, VIOCSETTOK is passed
the newpag flag.

This can be tested with the following program:

	#include <stdio.h>
	#include <stdlib.h>
	#include <keyutils.h>

	#define KEYCTL_SESSION_TO_PARENT	18

	#define OSERROR(X, S) do { if ((long)(X) == -1) { perror(S); exit(1); } } while(0)

	int main(int argc, char **argv)
	{
		key_serial_t keyring, key;
		long ret;

		keyring = keyctl_join_session_keyring(argv[1]);
		OSERROR(keyring, "keyctl_join_session_keyring");

		key = add_key("user", "a", "b", 1, keyring);
		OSERROR(key, "add_key");

		ret = keyctl(KEYCTL_SESSION_TO_PARENT);
		OSERROR(ret, "KEYCTL_SESSION_TO_PARENT");

		return 0;
	}

Compiled and linked with -lkeyutils, you should see something like:

	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: _ses
	355907932 --alswrv   4043    -1   \_ keyring: _uid.4043
	[dhowells@andromeda ~]$ /tmp/newpag
	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: _ses
	1055658746 --alswrv   4043  4043   \_ user: a
	[dhowells@andromeda ~]$ /tmp/newpag hello
	[dhowells@andromeda ~]$ keyctl show
	Session Keyring
	       -3 --alswrv   4043  4043  keyring: hello
	340417692 --alswrv   4043  4043   \_ user: a

Where the test program creates a new session keyring, sticks a user key named
'a' into it and then installs it on its parent.

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-02 21:29:22 +10:00
Paul Moore
2b980dbd77 lsm: Add hooks to the TUN driver
The TUN driver lacks any LSM hooks which makes it difficult for LSM modules,
such as SELinux, to enforce access controls on network traffic generated by
TUN users; this is particularly problematic for virtualization apps such as
QEMU and KVM.  This patch adds three new LSM hooks designed to control the
creation and attachment of TUN devices, the hooks are:

 * security_tun_dev_create()
   Provides access control for the creation of new TUN devices

 * security_tun_dev_post_create()
   Provides the ability to create the necessary socket LSM state for newly
   created TUN devices

 * security_tun_dev_attach()
   Provides access control for attaching to existing, persistent TUN devices
   and the ability to update the TUN device's socket LSM state as necessary

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@parisplace.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: James Morris <jmorris@namei.org>
2009-09-01 08:29:48 +10:00
Eric Paris
9188499cdb security: introducing security_request_module
Calling request_module() will trigger a userspace upcall which will load a
new module into the kernel.  This can be a dangerous event if the process
able to trigger request_module() is able to control either the modprobe
binary or the module binary.  This patch adds a new security hook to
request_module() which can be used by an LSM to control a processes ability
to call request_module().

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2009-08-14 11:18:37 +10:00
Ingo Molnar
9e48858f7d security: rename ptrace_may_access => ptrace_access_check
The ->ptrace_may_access() methods are named confusingly - the real
ptrace_may_access() returns a bool, while these security checks have
a retval convention.

Rename it to ptrace_access_check, to reduce the confusion factor.

[ Impact: cleanup, no code changed ]

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: James Morris <jmorris@namei.org>
2009-06-25 00:18:05 +10:00
Christoph Lameter
e0a94c2a63 security: use mmap_min_addr indepedently of security models
This patch removes the dependency of mmap_min_addr on CONFIG_SECURITY.
It also sets a default mmap_min_addr of 4096.

mmapping of addresses below 4096 will only be possible for processes
with CAP_SYS_RAWIO.

Signed-off-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Eric Paris <eparis@redhat.com>
Looks-ok-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: James Morris <jmorris@namei.org>
2009-06-04 12:07:48 +10:00
David Howells
800a964787 CacheFiles: Export things for CacheFiles
Export a number of functions for CacheFiles's use.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>
Acked-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Tested-by: Daire Byrne <Daire.Byrne@framestore.com>
2009-04-03 16:42:40 +01:00