Commit Graph

721 Commits

Author SHA1 Message Date
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
2463c26d50 SELinux: put name based create rules in a hashtable
To shorten the list we need to run if filename trans rules exist for the type
of the given parent directory I put them in a hashtable.  Given the policy we
are expecting to use in Fedora this takes the worst case list run from about
5,000 entries to 17.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-04-28 15:15:53 -04:00
Eric Paris
3f058ef778 SELinux: generic hashtab entry counter
Instead of a hashtab entry counter function only useful for range
transition rules make a function generic for any hashtable to use.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-04-28 15:15:52 -04:00
Eric Paris
be30b16d43 SELinux: calculate and print hashtab stats with a generic function
We have custom debug functions like rangetr_hash_eval and symtab_hash_eval
which do the same thing.  Just create a generic function that takes the name
of the hash table as an argument instead of having custom functions.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-04-28 15:15:52 -04:00
Eric Paris
03a4c0182a SELinux: skip filename trans rules if ttype does not match parent dir
Right now we walk to filename trans rule list for every inode that is
created.  First passes at policy using this facility creates around 5000
filename trans rules.  Running a list of 5000 entries every time is a bad
idea.  This patch adds a new ebitmap to policy which has a bit set for each
ttype that has at least 1 filename trans rule.  Thus when an inode is
created we can quickly determine if any rules exist for this parent
directory type and can skip the list if we know there is definitely no
relevant entry.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-04-28 15:15:52 -04:00
Eric Paris
2667991f60 SELinux: rename filename_compute_type argument to *type instead of *con
filename_compute_type() takes as arguments the numeric value of the type of
the subject and target.  It does not take a context.  Thus the names are
misleading.  Fix the argument names.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-04-28 15:15:51 -04:00
Eric Paris
4742600cf5 SELinux: fix comment to state filename_compute_type takes an objname not a qstr
filename_compute_type used to take a qstr, but it now takes just a name.
Fix the comments to indicate it is an objname, not a qstr.

Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-28 15:15:51 -04:00
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
6b697323a7 SELinux: security_read_policy should take a size_t not ssize_t
The len should be an size_t but is a ssize_t.  Easy enough fix to silence
build warnings.  We have no need for signed-ness.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: James Morris <jmorris@namei.org>
2011-04-25 10:19:02 -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
Eric Paris
425b473de5 SELinux: delete debugging printks from filename_trans rule processing
The filename_trans rule processing has some printk(KERN_ERR ) messages
which were intended as debug aids in creating the code but weren't removed
before it was submitted.  Remove them.

Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-20 11:45:14 -04:00
Harry Ciao
1214eac73f Initialize policydb.process_class eariler.
Initialize policydb.process_class once all symtabs read from policy image,
so that it could be used to setup the role_trans.tclass field when a lower
version policy.X is loaded.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-07 12:00:26 -04:00
Stephen Smalley
eba71de2cb selinux: Fix regression for Xorg
Commit 6f5317e730 introduced a bug in the
handling of userspace object classes that is causing breakage for Xorg
when XSELinux is enabled.  Fix the bug by changing map_class() to return
SECCLASS_NULL when the class cannot be mapped to a kernel object class.

Reported-by:  "Justin P. Mattock" <justinmattock@gmail.com>
Signed-off-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: James Morris <jmorris@namei.org>
2011-04-07 12:00:12 -04:00
Kohei Kaigai
f50a3ec961 selinux: add type_transition with name extension support for selinuxfs
The attached patch allows /selinux/create takes optional 4th argument
to support TYPE_TRANSITION with name extension for userspace object
managers.
If 4th argument is not supplied, it shall perform as existing kernel.
In fact, the regression test of SE-PostgreSQL works well on the patched
kernel.

Thanks,

Signed-off-by: KaiGai Kohei <kohei.kaigai@eu.nec.com>
[manually verify fuzz was not an issue, and it wasn't: eparis]
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-04-01 17:13:23 -04:00
Harry Ciao
c900ff323d SELinux: Write class field in role_trans_write.
If kernel policy version is >= 26, then write the class field of the
role_trans structure into the binary reprensentation.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-03-28 14:21:05 -04:00
Harry Ciao
63a312ca55 SELinux: Compute role in newcontext for all classes
Apply role_transition rules for all kinds of classes.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-03-28 14:21:01 -04:00
Harry Ciao
8023976cf4 SELinux: Add class support to the role_trans structure
If kernel policy version is >= 26, then the binary representation of
the role_trans structure supports specifying the class for the current
subject or the newly created object.

If kernel policy version is < 26, then the class field would be default
to the process class.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Acked-by:  Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: Eric Paris <eparis@redhat.com>
2011-03-28 14:20:58 -04:00
James Morris
fe3fa43039 Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next 2011-03-08 11:38:10 +11:00
James Morris
1cc26bada9 Merge branch 'master'; commit 'v2.6.38-rc7' into next 2011-03-08 10:55:06 +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
Harry Ciao
6f5317e730 SELinux: Socket retains creator role and MLS attribute
The socket SID would be computed on creation and no longer inherit
its creator's SID by default. Socket may have a different type but
needs to retain the creator's role and MLS attribute in order not
to break labeled networking and network access control.

The kernel value for a class would be used to determine if the class
if one of socket classes. If security_compute_sid is called from
userspace the policy value for a class would be mapped to the relevant
kernel value first.

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2011-03-03 15:19:43 -05:00
Harry Ciao
4bc6c2d5d8 SELinux: Auto-generate security_is_socket_class
The security_is_socket_class() is auto-generated by genheaders based
on classmap.h to reduce maintenance effort when a new class is defined
in SELinux kernel. The name for any socket class should be suffixed by
"socket" and doesn't contain more than one substr of "socket".

Signed-off-by: Harry Ciao <qingtao.cao@windriver.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
2011-03-03 15:19:43 -05:00
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
Eric Paris
47ac19ea42 selinux: drop unused packet flow permissions
These permissions are not used and can be dropped in the kernel
definitions.

Suggested-by: Stephen Smalley <sds@tycho.nsa.gov>
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
Steffen Klassert
8f82a6880d selinux: Fix check for xfrm selinux context algorithm
selinux_xfrm_sec_ctx_alloc accidentally checks the xfrm domain of
interpretation against the selinux context algorithm. This patch
fixes this by checking ctx_alg against the selinux context algorithm.

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 15:00:44 -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
Davidlohr Bueso
3ac285ff23 selinux: return -ENOMEM when memory allocation fails
Return -ENOMEM when memory allocation fails in cond_init_bool_indexes,
correctly propagating error code to caller.

Signed-off-by: Davidlohr Bueso <dave@gnu.org>
Signed-off-by: James Morris <jmorris@namei.org>
2011-01-24 11:35:47 +11:00
Shan Wei
ced3b93018 security:selinux: kill unused MAX_AVTAB_HASH_MASK and ebitmap_startbit
Kill unused MAX_AVTAB_HASH_MASK and ebitmap_startbit.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: James Morris <jmorris@namei.org>
2011-01-24 10:36:11 +11:00
Linus Torvalds
e0e736fc0d Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (30 commits)
  MAINTAINERS: Add tomoyo-dev-en ML.
  SELinux: define permissions for DCB netlink messages
  encrypted-keys: style and other cleanup
  encrypted-keys: verify datablob size before converting to binary
  trusted-keys: kzalloc and other cleanup
  trusted-keys: additional TSS return code and other error handling
  syslog: check cap_syslog when dmesg_restrict
  Smack: Transmute labels on specified directories
  selinux: cache sidtab_context_to_sid results
  SELinux: do not compute transition labels on mountpoint labeled filesystems
  This patch adds a new security attribute to Smack called SMACK64EXEC. It defines label that is used while task is running.
  SELinux: merge policydb_index_classes and policydb_index_others
  selinux: convert part of the sym_val_to_name array to use flex_array
  selinux: convert type_val_to_struct to flex_array
  flex_array: fix flex_array_put_ptr macro to be valid C
  SELinux: do not set automatic i_ino in selinuxfs
  selinux: rework security_netlbl_secattr_to_sid
  SELinux: standardize return code handling in selinuxfs.c
  SELinux: standardize return code handling in selinuxfs.c
  SELinux: standardize return code handling in policydb.c
  ...
2011-01-10 11:18:59 -08:00
Alexey Dobriyan
37721e1b0c headers: path.h redux
Remove path.h from sched.h and other files.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-01-10 08:51:44 -08:00
James Morris
aeda4ac3ef Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next 2011-01-10 10:40:42 +11:00
James Morris
d2e7ad1922 Merge branch 'master' into next
Conflicts:
	security/smack/smack_lsm.c

Verified and added fix by Stephen Rothwell <sfr@canb.auug.org.au>
Ok'd by Casey Schaufler <casey@schaufler-ca.com>

Signed-off-by: James Morris <jmorris@namei.org>
2011-01-10 09:46:24 +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
dc0474be3e fs: dcache rationalise dget variants
dget_locked was a shortcut to avoid the lazy lru manipulation when we already
held dcache_lock (lru manipulation was relatively cheap at that point).
However, how that the lru lock is an innermost one, we never hold it at any
caller, so the lock cost can now be avoided. We already have well working lazy
dcache LRU, so it should be fine to defer LRU manipulations to scan time.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:24 +11:00
Nick Piggin
b5c84bf6f6 fs: dcache remove dcache_lock
dcache_lock no longer protects anything. remove it.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:23 +11:00
Nick Piggin
2fd6b7f507 fs: dcache scale subdirs
Protect d_subdirs and d_child with d_lock, except in filesystems that aren't
using dcache_lock for these anyway (eg. using i_mutex).

Note: if we change the locking rule in future so that ->d_child protection is
provided only with ->d_parent->d_lock, it may allow us to reduce some locking.
But it would be an exception to an otherwise regular locking scheme, so we'd
have to see some good results. Probably not worthwhile.

Signed-off-by: Nick Piggin <npiggin@kernel.dk>
2011-01-07 17:50:21 +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
350e4f31e0 SELinux: define permissions for DCB netlink messages
Commit 2f90b865 added two new netlink message types to the netlink route
socket.  SELinux has hooks to define if netlink messages are allowed to
be sent or received, but it did not know about these two new message
types.  By default we allow such actions so noone likely noticed.  This
patch adds the proper definitions and thus proper permissions
enforcement.

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-12-16 12:50:17 -05:00
Eric Paris
73ff5fc0a8 selinux: cache sidtab_context_to_sid results
sidtab_context_to_sid takes up a large share of time when creating large
numbers of new inodes (~30-40% in oprofile runs).  This patch implements a
cache of 3 entries which is checked before we do a full context_to_sid lookup.
On one system this showed over a x3 improvement in the number of inodes that
could be created per second and around a 20% improvement on another system.

Any time we look up the same context string sucessivly (imagine ls -lZ) we
should hit this cache hot.  A cache miss should have a relatively minor affect
on performance next to doing the full table search.

All operations on the cache are done COMPLETELY lockless.  We know that all
struct sidtab_node objects created will never be deleted until a new policy is
loaded thus we never have to worry about a pointer being dereferenced.  Since
we also know that pointer assignment is atomic we know that the cache will
always have valid pointers.  Given this information we implement a FIFO cache
in an array of 3 pointers.  Every result (whether a cache hit or table lookup)
will be places in the 0 spot of the cache and the rest of the entries moved
down one spot.  The 3rd entry will be lost.

Races are possible and are even likely to happen.  Lets assume that 4 tasks
are hitting sidtab_context_to_sid.  The first task checks against the first
entry in the cache and it is a miss.  Now lets assume a second task updates
the cache with a new entry.  This will push the first entry back to the second
spot.  Now the first task might check against the second entry (which it
already checked) and will miss again.  Now say some third task updates the
cache and push the second entry to the third spot.  The first task my check
the third entry (for the third time!) and again have a miss.  At which point
it will just do a full table lookup.  No big deal!

Signed-off-by: Eric Paris <eparis@redhat.com>
2010-12-07 16:44:01 -05:00
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