Commit graph

367 commits

Author SHA1 Message Date
Linus Torvalds
95f4efb2d7 selinux: simplify and clean up inode_has_perm()
This is a rather hot function that is called with a potentially NULL
"struct common_audit_data" pointer argument.  And in that case it has to
provide and initialize its own dummy common_audit_data structure.

However, all the _common_ cases already pass it a real audit-data
structure, so that uncommon NULL case not only creates a silly run-time
test, more importantly it causes that function to have a big stack frame
for the dummy variable that isn't even used in the common case!

So get rid of that stupid run-time behavior, and make the (few)
functions that currently call with a NULL pointer just call a new helper
function instead (naturally called inode_has_perm_noapd(), since it has
no adp argument).

This makes the run-time test be a static code generation issue instead,
and allows for a much denser stack since none of the common callers need
the dummy structure.  And a denser stack not only means less stack space
usage, it means better cache behavior.  So we have a win-win-win from
this simplification: less code executed, smaller stack footprint, and
better cache behavior.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-08 15:11:56 -07:00
James Morris
b7b57551bb Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into for-linus
Conflicts:
	lib/flex_array.c
	security/selinux/avc.c
	security/selinux/hooks.c
	security/selinux/ss/policydb.c
	security/smack/smack_lsm.c

Manually resolve conflicts.

Signed-off-by: James Morris <jmorris@namei.org>
2011-05-24 23:20:19 +10:00
James Morris
6f23928454 Merge branch 'for-linus' of git://git.infradead.org/users/eparis/selinux into for-linus 2011-05-04 11:59:34 +10:00
Eric Paris
cb1e922fa1 SELinux: pass last path component in may_create
New inodes are created in a two stage process.  We first will compute the
label on a new inode in security_inode_create() and check if the
operation is allowed.  We will then actually re-compute that same label and
apply it in security_inode_init_security().  The change to do new label
calculations based in part on the last component of the path name only
passed the path component information all the way down the
security_inode_init_security hook.  Down the security_inode_create hook the
path information did not make it past may_create.  Thus the two calculations
came up differently and the permissions check might not actually be against
the label that is created.  Pass and use the same information in both places
to harmonize the calculations and checks.

Reported-by: Dominick Grift <domg472@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-28 16:12:41 -04:00
Eric Paris
2875fa0083 SELinux: introduce path_has_perm
We currently have inode_has_perm and dentry_has_perm.  dentry_has_perm just
calls inode_has_perm with additional audit data.  But dentry_has_perm can
take either a dentry or a path.  Split those to make the code obvious and
to fix the previous problem where I thought dentry_has_perm always had a
valid dentry and mnt.

Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-28 16:09:59 -04:00
Eric Paris
562abf6241 SELinux: pass last path component in may_create
New inodes are created in a two stage process.  We first will compute the
label on a new inode in security_inode_create() and check if the
operation is allowed.  We will then actually re-compute that same label and
apply it in security_inode_init_security().  The change to do new label
calculations based in part on the last component of the path name only
passed the path component information all the way down the
security_inode_init_security hook.  Down the security_inode_create hook the
path information did not make it past may_create.  Thus the two calculations
came up differently and the permissions check might not actually be against
the label that is created.  Pass and use the same information in both places
to harmonize the calculations and checks.

Reported-by: Dominick Grift <domg472@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-28 15:15:54 -04:00
Eric Paris
9ade0cf440 SELINUX: Make selinux cache VFS RCU walks safe
Now that the security modules can decide whether they support the
dcache RCU walk or not it's possible to make selinux a bit more
RCU friendly.  The SELinux AVC and security server access decision
code is RCU safe.  A specific piece of the LSM audit code may not
be RCU safe.

This patch makes the VFS RCU walk retry if it would hit the non RCU
safe chunk of code.  It will normally just work under RCU.  This is
done simply by passing the VFS RCU state as a flag down into the
avc_audit() code and returning ECHILD there if it would have an issue.

Based-on-patch-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-25 18:16:32 -07:00
Eric Paris
a269434d2f LSM: separate LSM_AUDIT_DATA_DENTRY from LSM_AUDIT_DATA_PATH
This patch separates and audit message that only contains a dentry from
one that contains a full path.  This allows us to make it harder to
misuse the interfaces or for the interfaces to be implemented wrong.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2011-04-25 18:14:07 -04:00
Eric Paris
f48b739984 LSM: split LSM_AUDIT_DATA_FS into _PATH and _INODE
The lsm common audit code has wacky contortions making sure which pieces
of information are set based on if it was given a path, dentry, or
inode.  Split this into path and inode to get rid of some of the code
complexity.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2011-04-25 18:13:15 -04:00
Eric Paris
0dc1ba24f7 SELINUX: Make selinux cache VFS RCU walks safe
Now that the security modules can decide whether they support the
dcache RCU walk or not it's possible to make selinux a bit more
RCU friendly.  The SELinux AVC and security server access decision
code is RCU safe.  A specific piece of the LSM audit code may not
be RCU safe.

This patch makes the VFS RCU walk retry if it would hit the non RCU
safe chunk of code.  It will normally just work under RCU.  This is
done simply by passing the VFS RCU state as a flag down into the
avc_audit() code and returning ECHILD there if it would have an issue.

Based-on-patch-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-25 16:24:41 -04:00
Andi Kleen
1c99042974 SECURITY: Move exec_permission RCU checks into security modules
Right now all RCU walks fall back to reference walk when CONFIG_SECURITY
is enabled, even though just the standard capability module is active.
This is because security_inode_exec_permission unconditionally fails
RCU walks.

Move this decision to the low level security module. This requires
passing the RCU flags down the security hook. This way at least
the capability module and a few easy cases in selinux/smack work
with RCU walks with CONFIG_SECURITY=y

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-25 10:20:32 -04:00
Eric Paris
a35c6c8368 SELinux: silence build warning when !CONFIG_BUG
If one builds a kernel without CONFIG_BUG there are a number of 'may be
used uninitialized' warnings.  Silence these by returning after the BUG().

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-04-25 10:18:27 -04:00
Andi Kleen
8c9e80ed27 SECURITY: Move exec_permission RCU checks into security modules
Right now all RCU walks fall back to reference walk when CONFIG_SECURITY
is enabled, even though just the standard capability module is active.
This is because security_inode_exec_permission unconditionally fails
RCU walks.

Move this decision to the low level security module. This requires
passing the RCU flags down the security hook. This way at least
the capability module and a few easy cases in selinux/smack work
with RCU walks with CONFIG_SECURITY=y

Signed-off-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-04-22 16:17:29 -07:00
Serge E. Hallyn
2e14967075 userns: rename is_owner_or_cap to inode_owner_or_capable
And give it a kernel-doc comment.

[akpm@linux-foundation.org: btrfs changed in linux-next]
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:47:13 -07:00
Serge E. Hallyn
3486740a4f userns: security: make capabilities relative to the user namespace
- Introduce ns_capable to test for a capability in a non-default
  user namespace.
- Teach cap_capable to handle capabilities in a non-default
  user namespace.

The motivation is to get to the unprivileged creation of new
namespaces.  It looks like this gets us 90% of the way there, with
only potential uid confusion issues left.

I still need to handle getting all caps after creation but otherwise I
think I have a good starter patch that achieves all of your goals.

Changelog:
	11/05/2010: [serge] add apparmor
	12/14/2010: [serge] fix capabilities to created user namespaces
	Without this, if user serge creates a user_ns, he won't have
	capabilities to the user_ns he created.  THis is because we
	were first checking whether his effective caps had the caps
	he needed and returning -EPERM if not, and THEN checking whether
	he was the creator.  Reverse those checks.
	12/16/2010: [serge] security_real_capable needs ns argument in !security case
	01/11/2011: [serge] add task_ns_capable helper
	01/11/2011: [serge] add nsown_capable() helper per Bastian Blank suggestion
	02/16/2011: [serge] fix a logic bug: the root user is always creator of
		    init_user_ns, but should not always have capabilities to
		    it!  Fix the check in cap_capable().
	02/21/2011: Add the required user_ns parameter to security_capable,
		    fixing a compile failure.
	02/23/2011: Convert some macros to functions as per akpm comments.  Some
		    couldn't be converted because we can't easily forward-declare
		    them (they are inline if !SECURITY, extern if SECURITY).  Add
		    a current_user_ns function so we can use it in capability.h
		    without #including cred.h.  Move all forward declarations
		    together to the top of the #ifdef __KERNEL__ section, and use
		    kernel-doc format.
	02/23/2011: Per dhowells, clean up comment in cap_capable().
	02/23/2011: Per akpm, remove unreachable 'return -EPERM' in cap_capable.

(Original written and signed off by Eric;  latest, modified version
acked by him)

[akpm@linux-foundation.org: fix build]
[akpm@linux-foundation.org: export current_user_ns() for ecryptfs]
[serge.hallyn@canonical.com: remove unneeded extra argument in selinux's task_has_capability]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Acked-by: "Eric W. Biederman" <ebiederm@xmission.com>
Acked-by: Daniel Lezcano <daniel.lezcano@free.fr>
Acked-by: David Howells <dhowells@redhat.com>
Cc: James Morris <jmorris@namei.org>
Signed-off-by: Serge E. Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-03-23 19:47:02 -07:00
Linus Torvalds
7a6362800c Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1480 commits)
  bonding: enable netpoll without checking link status
  xfrm: Refcount destination entry on xfrm_lookup
  net: introduce rx_handler results and logic around that
  bonding: get rid of IFF_SLAVE_INACTIVE netdev->priv_flag
  bonding: wrap slave state work
  net: get rid of multiple bond-related netdevice->priv_flags
  bonding: register slave pointer for rx_handler
  be2net: Bump up the version number
  be2net: Copyright notice change. Update to Emulex instead of ServerEngines
  e1000e: fix kconfig for crc32 dependency
  netfilter ebtables: fix xt_AUDIT to work with ebtables
  xen network backend driver
  bonding: Improve syslog message at device creation time
  bonding: Call netif_carrier_off after register_netdevice
  bonding: Incorrect TX queue offset
  net_sched: fix ip_tos2prio
  xfrm: fix __xfrm_route_forward()
  be2net: Fix UDP packet detected status in RX compl
  Phonet: fix aligned-mode pipe socket buffer header reserve
  netxen: support for GbE port settings
  ...

Fix up conflicts in drivers/staging/brcm80211/brcmsmac/wl_mac80211.c
with the staging updates.
2011-03-16 16:29:25 -07:00
David S. Miller
1d28f42c1b net: Put flowi_* prefix on AF independent members of struct flowi
I intend to turn struct flowi into a union of AF specific flowi
structs.  There will be a common structure that each variant includes
first, much like struct sock_common.

This is the first step to move in that direction.

Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-12 15:08:44 -08:00
James Morris
fe3fa43039 Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next 2011-03-08 11:38:10 +11:00
Eric Paris
026eb167ae SELinux: implement the new sb_remount LSM hook
For SELinux we do not allow security information to change during a remount
operation.  Thus this hook simply strips the security module options from
the data and verifies that those are the same options as exist on the
current superblock.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-03-03 16:12:28 -05:00
Harry Ciao
2ad18bdf3b SELinux: Compute SID for the newly created socket
The security context for the newly created socket shares the same
user, role and MLS attribute as its creator but may have a different
type, which could be specified by a type_transition rule in the relevant
policy package.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
[fix call to security_transition_sid to include qstr, Eric Paris]
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2011-03-03 15:19:44 -05:00
Patrick McHardy
c53fa1ed92 netlink: kill loginuid/sessionid/sid members from struct netlink_skb_parms
Netlink message processing in the kernel is synchronous these days, the
session information can be collected when needed.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-03-03 10:55:40 -08:00
Eric Paris
0b24dcb7f2 Revert "selinux: simplify ioctl checking"
This reverts commit 242631c49d.

Conflicts:

	security/selinux/hooks.c

SELinux used to recognize certain individual ioctls and check
permissions based on the knowledge of the individual ioctl.  In commit
242631c49d the SELinux code stopped trying to understand
individual ioctls and to instead looked at the ioctl access bits to
determine in we should check read or write for that operation.  This
same suggestion was made to SMACK (and I believe copied into TOMOYO).
But this suggestion is total rubbish.  The ioctl access bits are
actually the access requirements for the structure being passed into the
ioctl, and are completely unrelated to the operation of the ioctl or the
object the ioctl is being performed upon.

Take FS_IOC_FIEMAP as an example.  FS_IOC_FIEMAP is defined as:

FS_IOC_FIEMAP _IOWR('f', 11, struct fiemap)

So it has access bits R and W.  What this really means is that the
kernel is going to both read and write to the struct fiemap.  It has
nothing at all to do with the operations that this ioctl might perform
on the file itself!

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2011-02-25 15:40:00 -05:00
Steffen Klassert
4a7ab3dcad selinux: Fix packet forwarding checks on postrouting
The IPSKB_FORWARDED and IP6SKB_FORWARDED flags are used only in the
multicast forwarding case to indicate that a packet looped back after
forward. So these flags are not a good indicator for packet forwarding.
A better indicator is the incoming interface. If we have no socket context,
but an incoming interface and we see the packet in the ip postroute hook,
the packet is going to be forwarded.

With this patch we use the incoming interface as an indicator on packet
forwarding.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-02-25 15:00:51 -05:00
Steffen Klassert
b9679a7618 selinux: Fix wrong checks for selinux_policycap_netpeer
selinux_sock_rcv_skb_compat and selinux_ip_postroute_compat are just
called if selinux_policycap_netpeer is not set. However in these
functions we check if selinux_policycap_netpeer is set. This leads
to some dead code and to the fact that selinux_xfrm_postroute_last
is never executed. This patch removes the dead code and the checks
for selinux_policycap_netpeer in the compatibility functions.

Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Acked-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-02-25 15:00:47 -05:00
Tetsuo Handa
2edeaa34a6 CRED: Fix BUG() upon security_cred_alloc_blank() failure
In cred_alloc_blank() since 2.6.32, abort_creds(new) is called with
new->security == NULL and new->magic == 0 when security_cred_alloc_blank()
returns an error.  As a result, BUG() will be triggered if SELinux is enabled
or CONFIG_DEBUG_CREDENTIALS=y.

If CONFIG_DEBUG_CREDENTIALS=y, BUG() is called from __invalid_creds() because
cred->magic == 0.  Failing that, BUG() is called from selinux_cred_free()
because selinux_cred_free() is not expecting cred->security == NULL.  This does
not affect smack_cred_free(), tomoyo_cred_free() or apparmor_cred_free().

Fix these bugs by

(1) Set new->magic before calling security_cred_alloc_blank().

(2) Handle null cred->security in creds_are_invalid() and selinux_cred_free().

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-02-07 14:04:00 -08:00
Lucian Adrian Grijincu
8e6c96935f security/selinux: fix /proc/sys/ labeling
This fixes an old (2007) selinux regression: filesystem labeling for
/proc/sys returned
     -r--r--r-- unknown                          /proc/sys/fs/file-nr
instead of
     -r--r--r-- system_u:object_r:sysctl_fs_t:s0 /proc/sys/fs/file-nr

Events that lead to breaking of /proc/sys/ selinux labeling:

1) sysctl was reimplemented to route all calls through /proc/sys/

    commit 77b14db502
    [PATCH] sysctl: reimplement the sysctl proc support

2) proc_dir_entry was removed from ctl_table:

    commit 3fbfa98112
    [PATCH] sysctl: remove the proc_dir_entry member for the sysctl tables

3) selinux still walked the proc_dir_entry tree to apply
   labeling. Because ctl_tables don't have a proc_dir_entry, we did
   not label /proc/sys/ inodes any more. To achieve this the /proc/sys/
   inodes were marked private and private inodes were ignored by
   selinux.

    commit bbaca6c2e7
    [PATCH] selinux: enhance selinux to always ignore private inodes

    commit 86a71dbd3e
    [PATCH] sysctl: hide the sysctl proc inodes from selinux

Access control checks have been done by means of a special sysctl hook
that was called for read/write accesses to any /proc/sys/ entry.

We don't have to do this because, instead of walking the
proc_dir_entry tree we can walk the dentry tree (as done in this
patch). With this patch:
* we don't mark /proc/sys/ inodes as private
* we don't need the sysclt security hook
* we walk the dentry tree to find the path to the inode.

We have to strip the PID in /proc/PID/ entries that have a
proc_dir_entry because selinux does not know how to label paths like
'/1/net/rpc/nfsd.fh' (and defaults to 'proc_t' labeling). Selinux does
know of '/net/rpc/nfsd.fh' (and applies the 'sysctl_rpc_t' label).

PID stripping from the path was done implicitly in the previous code
because the proc_dir_entry tree had the root in '/net' in the example
from above. The dentry tree has the root in '/1'.

Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: Lucian Adrian Grijincu <lucian.grijincu@gmail.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-02-01 11:53:54 -05:00
Eric Paris
652bb9b0d6 SELinux: Use dentry name in new object labeling
Currently SELinux has rules which label new objects according to 3 criteria.
The label of the process creating the object, the label of the parent
directory, and the type of object (reg, dir, char, block, etc.)  This patch
adds a 4th criteria, the dentry name, thus we can distinguish between
creating a file in an etc_t directory called shadow and one called motd.

There is no file globbing, regex parsing, or anything mystical.  Either the
policy exactly (strcmp) matches the dentry name of the object or it doesn't.
This patch has no changes from today if policy does not implement the new
rules.

Signed-off-by: Eric Paris <eparis@redhat.com>
2011-02-01 11:12:30 -05:00
Eric Paris
2a7dba391e fs/vfs/security: pass last path component to LSM on inode creation
SELinux would like to implement a new labeling behavior of newly created
inodes.  We currently label new inodes based on the parent and the creating
process.  This new behavior would also take into account the name of the
new object when deciding the new label.  This is not the (supposed) full path,
just the last component of the path.

This is very useful because creating /etc/shadow is different than creating
/etc/passwd but the kernel hooks are unable to differentiate these
operations.  We currently require that userspace realize it is doing some
difficult operation like that and than userspace jumps through SELinux hoops
to get things set up correctly.  This patch does not implement new
behavior, that is obviously contained in a seperate SELinux patch, but it
does pass the needed name down to the correct LSM hook.  If no such name
exists it is fine to pass NULL.

Signed-off-by: Eric Paris <eparis@redhat.com>
2011-02-01 11:12:29 -05:00
James Morris
aeda4ac3ef Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next 2011-01-10 10:40:42 +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
David S. Miller
17f7f4d9fc Merge branch 'master' of master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
Conflicts:
	net/ipv4/fib_frontend.c
2010-12-26 22:37:05 -08:00
Eric Paris
415103f993 SELinux: do not compute transition labels on mountpoint labeled filesystems
selinux_inode_init_security computes transitions sids even for filesystems
that use mount point labeling.  It shouldn't do that.  It should just use
the mount point label always and no matter what.

This causes 2 problems.  1) it makes file creation slower than it needs to be
since we calculate the transition sid and 2) it allows files to be created
with a different label than the mount point!

# id -Z
staff_u:sysadm_r:sysadm_t:s0-s0:c0.c1023
# sesearch --type --class file --source sysadm_t --target tmp_t
Found 1 semantic te rules:
   type_transition sysadm_t tmp_t : file user_tmp_t;

# mount -o loop,context="system_u:object_r:tmp_t:s0"  /tmp/fs /mnt/tmp

# ls -lZ /mnt/tmp
drwx------. root root system_u:object_r:tmp_t:s0       lost+found
# touch /mnt/tmp/file1
# ls -lZ /mnt/tmp
-rw-r--r--. root root staff_u:object_r:user_tmp_t:s0   file1
drwx------. root root system_u:object_r:tmp_t:s0       lost+found

Whoops, we have a mount point labeled filesystem tmp_t with a user_tmp_t
labeled file!

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Reviewed-by: James Morris <jmorris@namei.org>
2010-12-02 16:14:51 -05:00
Eric Paris
2fe66ec242 SELinux: indicate fatal error in compat netfilter code
The SELinux ip postroute code indicates when policy rejected a packet and
passes the error back up the stack.  The compat code does not.  This patch
sends the same kind of error back up the stack in the compat code.

Based-on-patch-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-23 10:50:17 -08:00
Eric Paris
04f6d70f6e SELinux: Only return netlink error when we know the return is fatal
Some of the SELinux netlink code returns a fatal error when the error might
actually be transient.  This patch just silently drops packets on
potentially transient errors but continues to return a permanant error
indicator when the denial was because of policy.

Based-on-comments-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-23 10:50:17 -08:00
Eric Paris
1f1aaf8282 SELinux: return -ECONNREFUSED from ip_postroute to signal fatal error
The SELinux netfilter hooks just return NF_DROP if they drop a packet.  We
want to signal that a drop in this hook is a permanant fatal error and is not
transient.  If we do this the error will be passed back up the stack in some
places and applications will get a faster interaction that something went
wrong.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2010-11-17 10:54:35 -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
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
Nick Piggin
d996b62a8d tty: fix fu_list abuse
tty: fix fu_list abuse

tty code abuses fu_list, which causes a bug in remount,ro handling.

If a tty device node is opened on a filesystem, then the last link to the inode
removed, the filesystem will be allowed to be remounted readonly. This is
because fs_may_remount_ro does not find the 0 link tty inode on the file sb
list (because the tty code incorrectly removed it to use for its own purpose).
This can result in a filesystem with errors after it is marked "clean".

Taking idea from Christoph's initial patch, allocate a tty private struct
at file->private_data and put our required list fields in there, linking
file and tty. This makes tty nodes behave the same way as other device nodes
and avoid meddling with the vfs, and avoids this bug.

The error handling is not trivial in the tty code, so for this bugfix, I take
the simple approach of using __GFP_NOFAIL and don't worry about memory errors.
This is not a problem because our allocator doesn't fail small allocs as a rule
anyway. So proper error handling is left as an exercise for tty hackers.

[ Arguably filesystem's device inode would ideally be divorced from the
driver's pseudo inode when it is opened, but in practice it's not clear whether
that will ever be worth implementing. ]

Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:47 -04:00
Nick Piggin
ee2ffa0dfd fs: cleanup files_lock locking
fs: cleanup files_lock locking

Lock tty_files with a new spinlock, tty_files_lock; provide helpers to
manipulate the per-sb files list; unexport the files_lock spinlock.

Cc: linux-kernel@vger.kernel.org
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Acked-by: Andi Kleen <ak@linux.intel.com>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>
Signed-off-by: Nick Piggin <npiggin@kernel.dk>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-08-18 08:35:47 -04:00
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
Eric Paris
49b7b8de46 selinux: place open in the common file perms
kernel can dynamically remap perms.  Drop the open lookup table and put open
in the common file perms.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:35:08 +10:00
Eric Paris
b782e0a68d SELinux: special dontaudit for access checks
Currently there are a number of applications (nautilus being the main one) which
calls access() on files in order to determine how they should be displayed.  It
is normal and expected that nautilus will want to see if files are executable
or if they are really read/write-able.  access() should return the real
permission.  SELinux policy checks are done in access() and can result in lots
of AVC denials as policy denies RWX on files which DAC allows.  Currently
SELinux must dontaudit actual attempts to read/write/execute a file in
order to silence these messages (and not flood the logs.)  But dontaudit rules
like that can hide real attacks.  This patch addes a new common file
permission audit_access.  This permission is special in that it is meaningless
and should never show up in an allow rule.  Instead the only place this
permission has meaning is in a dontaudit rule like so:

dontaudit nautilus_t sbin_t:file audit_access

With such a rule if nautilus just checks access() we will still get denied and
thus userspace will still get the correct answer but we will not log the denial.
If nautilus attempted to actually perform one of the forbidden actions
(rather than just querying access(2) about it) we would still log a denial.
This type of dontaudit rule should be used sparingly, as it could be a
method for an attacker to probe the system permissions without detection.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:35:07 +10:00
Eric Paris
d09ca73979 security: make LSMs explicitly mask off permissions
SELinux needs to pass the MAY_ACCESS flag so it can handle auditting
correctly.  Presently the masking of MAY_* flags is done in the VFS.  In
order to allow LSMs to decide what flags they care about and what flags
they don't just pass them all and the each LSM mask off what they don't
need.  This patch should contain no functional changes to either the VFS or
any LSM.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by:  Stephen D. Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:35:07 +10:00
Mimi Zohar
af4f136056 security: move LSM xattrnames to xattr.h
Make the security extended attributes names global. Updated to move
the remaining Smack xattrs.

Signed-off-by: Mimi Zohar <zohar@us.ibm.com>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:34:57 +10:00
Paul Moore
5fb49870e6 selinux: Use current_security() when possible
There were a number of places using the following code pattern:

  struct cred *cred = current_cred();
  struct task_security_struct *tsec = cred->security;

... which were simplified to the following:

  struct task_security_struct *tsec = current_security();

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:34:39 +10:00
Paul Moore
253bfae6e0 selinux: Convert socket related access controls to use socket labels
At present, the socket related access controls use a mix of inode and
socket labels; while there should be no practical difference (they
_should_ always be the same), it makes the code more confusing.  This
patch attempts to convert all of the socket related access control
points (with the exception of some of the inode/fd based controls) to
use the socket's own label.  In the process, I also converted the
socket_has_perm() function to take a 'sock' argument instead of a
'socket' since that was adding a bit more overhead in some cases.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:34:39 +10:00
Paul Moore
84914b7ed1 selinux: Shuffle the sk_security_struct alloc and free routines
The sk_alloc_security() and sk_free_security() functions were only being
called by the selinux_sk_alloc_security() and selinux_sk_free_security()
functions so we just move the guts of the alloc/free routines to the
callers and eliminate a layer of indirection.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:34:38 +10:00
Paul Moore
d4f2d97841 selinux: Consolidate sockcreate_sid logic
Consolidate the basic sockcreate_sid logic into a single helper function
which allows us to do some cleanups in the related code.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:34:37 +10:00
Paul Moore
4d1e24514d selinux: Set the peer label correctly on connected UNIX domain sockets
Correct a problem where we weren't setting the peer label correctly on
the client end of a pair of connected UNIX sockets.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-08-02 15:34:37 +10:00