Commit Graph

240 Commits

Author SHA1 Message Date
Lukasz Pawelczyk
6686781852 Smack: adds smackfs/ptrace interface
This allows to limit ptrace beyond the regular smack access rules.
It adds a smackfs/ptrace interface that allows smack to be configured
to require equal smack labels for PTRACE_MODE_ATTACH access.
See the changes in Documentation/security/Smack.txt below for details.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2014-04-11 14:34:35 -07:00
Lukasz Pawelczyk
5663884caa Smack: unify all ptrace accesses in the smack
The decision whether we can trace a process is made in the following
functions:
	smack_ptrace_traceme()
	smack_ptrace_access_check()
	smack_bprm_set_creds() (in case the proces is traced)

This patch unifies all those decisions by introducing one function that
checks whether ptrace is allowed: smk_ptrace_rule_check().

This makes possible to actually trace with TRACEME where first the
TRACEME itself must be allowed and then exec() on a traced process.

Additional bugs fixed:
- The decision is made according to the mode parameter that is now correctly
  translated from PTRACE_MODE_* to MAY_* instead of being treated 1:1.
  PTRACE_MODE_READ requires MAY_READ.
  PTRACE_MODE_ATTACH requires MAY_READWRITE.
- Add a smack audit log in case of exec() refused by bprm_set_creds().
- Honor the PTRACE_MODE_NOAUDIT flag and don't put smack audit info
  in case this flag is set.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2014-04-11 14:34:26 -07:00
Lukasz Pawelczyk
959e6c7f1e Smack: fix the subject/object order in smack_ptrace_traceme()
The order of subject/object is currently reversed in
smack_ptrace_traceme(). It is currently checked if the tracee has a
capability to trace tracer and according to this rule a decision is made
whether the tracer will be allowed to trace tracee.

Signed-off-by: Lukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2014-04-11 14:34:17 -07:00
José Bollo
55dfc5da1a Minor improvement of 'smack_sb_kern_mount'
Fix a possible memory access fault when transmute is true and isp is NULL.

Signed-off-by: José Bollo <jose.bollo@open.eurogiciel.org>
2014-04-11 14:33:59 -07:00
Dmitry Kasatkin
fffea214ab smack: fix key permission verification
For any keyring access type SMACK always used MAY_READWRITE access check.
It prevents reading the key with label "_", which should be allowed for anyone.

This patch changes default access check to MAY_READ and use MAY_READWRITE in only
appropriate cases.

Signed-off-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2014-03-14 17:44:49 +00:00
David Howells
f5895943d9 KEYS: Move the flags representing required permission to linux/key.h
Move the flags representing required permission to linux/key.h as the perm
parameter of security_key_permission() is in terms of them - and not the
permissions mask flags used in key->perm.

Whilst we're at it:

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

 (2) Don't use key_perm_t for a mask of required permissions, but rather limit
     it to the permissions mask attached to the key and arguments related
     directly to that.

Signed-off-by: David Howells <dhowells@redhat.com>
Tested-by: Dmitry Kasatkin <d.kasatkin@samsung.com>
2014-03-14 17:44:49 +00:00
Linus Torvalds
6dd9158ae8 Merge git://git.infradead.org/users/eparis/audit
Pull audit update from Eric Paris:
 "Again we stayed pretty well contained inside the audit system.
  Venturing out was fixing a couple of function prototypes which were
  inconsistent (didn't hurt anything, but we used the same value as an
  int, uint, u32, and I think even a long in a couple of places).

  We also made a couple of minor changes to when a couple of LSMs called
  the audit system.  We hoped to add aarch64 audit support this go
  round, but it wasn't ready.

  I'm disappearing on vacation on Thursday.  I should have internet
  access, but it'll be spotty.  If anything goes wrong please be sure to
  cc rgb@redhat.com.  He'll make fixing things his top priority"

* git://git.infradead.org/users/eparis/audit: (50 commits)
  audit: whitespace fix in kernel-parameters.txt
  audit: fix location of __net_initdata for audit_net_ops
  audit: remove pr_info for every network namespace
  audit: Modify a set of system calls in audit class definitions
  audit: Convert int limit uses to u32
  audit: Use more current logging style
  audit: Use hex_byte_pack_upper
  audit: correct a type mismatch in audit_syscall_exit()
  audit: reorder AUDIT_TTY_SET arguments
  audit: rework AUDIT_TTY_SET to only grab spin_lock once
  audit: remove needless switch in AUDIT_SET
  audit: use define's for audit version
  audit: documentation of audit= kernel parameter
  audit: wait_for_auditd rework for readability
  audit: update MAINTAINERS
  audit: log task info on feature change
  audit: fix incorrect set of audit_sock
  audit: print error message when fail to create audit socket
  audit: fix dangling keywords in audit_log_set_loginuid() output
  audit: log on errors from filter user rules
  ...
2014-01-23 18:08:10 -08:00
Richard Guy Briggs
4eb0f4abfb smack: call WARN_ONCE() instead of calling audit_log_start()
Remove the call to audit_log() (which call audit_log_start()) and deal with
the errors in the caller, logging only once if the condition is met.  Calling
audit_log_start() in this location makes buffer allocation and locking more
complicated in the calling tree (audit_filter_user()).

Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
2014-01-13 22:32:06 -05:00
Casey Schaufler
4482a44f6a Smack: File receive audit correction
Eric Paris politely points out:

    Inside smack_file_receive() it seems like you are initting the audit
    field with LSM_AUDIT_DATA_TASK.  And then use
    smk_ad_setfield_u_fs_path().

    Seems like LSM_AUDIT_DATA_PATH would make more sense.  (and depending
    on how it's used fix a crash...)

He is correct. This puts things in order.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-12-31 13:35:27 -08:00
Casey Schaufler
24ea1b6efc Smack: Rationalize mount restrictions
The mount restrictions imposed by Smack rely heavily on the
use of the filesystem "floor", which is the label that all
processes writing to the filesystem must have access to. It
turns out that while the "floor" notion is sound, it has yet
to be fully implemented and has never been used.

The sb_mount and sb_umount hooks only make sense if the
filesystem floor is used actively, and it isn't. They can
be reintroduced if a rational restriction comes up. Until
then, they get removed.

The sb_kern_mount hook is required for the option processing.
It is too permissive in the case of unprivileged mounts,
effectively bypassing the CAP_MAC_ADMIN restrictions if
any of the smack options are specified. Unprivileged mounts
are no longer allowed to set Smack filesystem options.
Additionally, the root and default values are set to the
label of the caller, in keeping with the policy that objects
get the label of their creator.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-12-31 13:35:16 -08:00
Casey Schaufler
4afde48be8 Smack: change rule cap check
smk_write_change_rule() is calling capable rather than
the more correct smack_privileged(). This allows for setting
rules in violation of the onlycap facility. This is the
simple repair.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-12-23 15:57:43 -08:00
Casey Schaufler
00f84f3f2e Smack: Make the syslog control configurable
The syslog control requires that the calling proccess
have the floor ("_") Smack label. Tizen does not run any
processes except for kernel helpers with the floor label.
This changes allows the admin to configure a specific
label for syslog. The default value is the star ("*")
label, effectively removing the restriction. The value
can be set using smackfs/syslog for anyone who wants
a more restrictive behavior.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-12-23 15:50:55 -08:00
Casey Schaufler
19760ad03c Smack: Prevent the * and @ labels from being used in SMACK64EXEC
Smack prohibits processes from using the star ("*") and web ("@") labels
because we don't want files with those labels getting created implicitly.
All setting of those labels should be done explicitly. The trouble is that
there is no check for these labels in the processing of SMACK64EXEC. That
is repaired.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-12-19 13:05:24 -08:00
Jarkko Sakkinen
398ce07370 smack: fix: allow either entry be missing on access/access2 check (v2)
This is a regression caused by f7112e6c. When either subject or
object is not found the answer for access should be no. This
patch fixes the situation. '0' is written back instead of failing
with -EINVAL.

v2: cosmetic style fixes

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@linux.intel.com>
2013-12-11 10:48:55 -08:00
Casey Schaufler
b5dfd8075b Smack: Ptrace access check mode
When the ptrace security hooks were split the addition of
a mode parameter was not taken advantage of in the Smack
ptrace access check. This changes the access check from
always looking for read and write access to using the
passed mode. This will make use of /proc much happier.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-10-28 10:23:36 -07:00
Casey Schaufler
c0ab6e56dc Smack: Implement lock security mode
Linux file locking does not follow the same rules
as other mechanisms. Even though it is a write operation
a process can set a read lock on files which it has open
only for read access. Two programs with read access to
a file can use read locks to communicate.

This is not acceptable in a Mandatory Access Control
environment. Smack treats setting a read lock as the
write operation that it is. Unfortunately, many programs
assume that setting a read lock is a read operation.
These programs are unhappy in the Smack environment.

This patch introduces a new access mode (lock) to address
this problem. A process with lock access to a file can
set a read lock. A process with write access to a file can
set a read lock or a write lock. This prevents a situation
where processes are granted write access just so they can
set read locks.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-10-18 09:39:33 -07:00
Linus Torvalds
11c7b03d42 Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "Nothing major for this kernel, just maintenance updates"

* 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security: (21 commits)
  apparmor: add the ability to report a sha1 hash of loaded policy
  apparmor: export set of capabilities supported by the apparmor module
  apparmor: add the profile introspection file to interface
  apparmor: add an optional profile attachment string for profiles
  apparmor: add interface files for profiles and namespaces
  apparmor: allow setting any profile into the unconfined state
  apparmor: make free_profile available outside of policy.c
  apparmor: rework namespace free path
  apparmor: update how unconfined is handled
  apparmor: change how profile replacement update is done
  apparmor: convert profile lists to RCU based locking
  apparmor: provide base for multiple profiles to be replaced at once
  apparmor: add a features/policy dir to interface
  apparmor: enable users to query whether apparmor is enabled
  apparmor: remove minimum size check for vmalloc()
  Smack: parse multiple rules per write to load2, up to PAGE_SIZE-1 bytes
  Smack: network label match fix
  security: smack: add a hash table to quicken smk_find_entry()
  security: smack: fix memleak in smk_write_rules_list()
  xattr: Constify ->name member of "struct xattr".
  ...
2013-09-07 14:34:07 -07:00
James Morris
7320336146 Merge branch 'smack-for-3.12' of git://git.gitorious.org/smack-next/kernel into ra-next 2013-08-23 02:50:12 +10:00
Rafal Krypa
10289b0f73 Smack: parse multiple rules per write to load2, up to PAGE_SIZE-1 bytes
Smack interface for loading rules has always parsed only single rule from
data written to it. This requires user program to call one write() per
each rule it wants to load.
This change makes it possible to write multiple rules, separated by new
line character. Smack will load at most PAGE_SIZE-1 characters and properly
return number of processed bytes. In case when user buffer is larger, it
will be additionally truncated. All characters after last \n will not get
parsed to avoid partial rule near input buffer boundary.

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2013-08-12 11:51:40 -07:00
Casey Schaufler
6ea062475a Smack: IPv6 casting error fix for 3.11
The original implementation of the Smack IPv6 port based
local controls works most of the time using a sockaddr as
a temporary variable, but not always as it overflows in
some circumstances. The correct data is a sockaddr_in6.
A struct sockaddr isn't as large as a struct sockaddr_in6.
There would need to be casting one way or the other. This
patch gets it the right way.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2013-08-06 20:53:54 +10:00
Casey Schaufler
677264e8fb Smack: network label match fix
The Smack code that matches incoming CIPSO tags with Smack labels
reaches through the NetLabel interfaces and compares the network
data with the CIPSO header associated with a Smack label. This was
done in a ill advised attempt to optimize performance. It works
so long as the categories fit in a single capset, but this isn't
always the case.

This patch changes the Smack code to use the appropriate NetLabel
interfaces to compare the incoming CIPSO header with the CIPSO
header associated with a label. It will always match the CIPSO
headers correctly.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-08-01 20:04:02 -07:00
Tomasz Stanislawski
4d7cf4a1f4 security: smack: add a hash table to quicken smk_find_entry()
Accepted for the smack-next tree after changing the number of
slots from 128 to 16.

This patch adds a hash table to quicken searching of a smack label by its name.

Basically, the patch improves performance of SMACK initialization.  Parsing of
rules involves translation from a string to a smack_known (aka label) entity
which is done in smk_find_entry().

The current implementation of the function iterates over a global list of
smack_known resulting in O(N) complexity for smk_find_entry().  The total
complexity of SMACK initialization becomes O(rules * labels).  Therefore it
scales quadratically with a complexity of a system.

Applying the patch reduced the complexity of smk_find_entry() to O(1) as long
as number of label is in hundreds. If the number of labels is increased please
update SMACK_HASH_SLOTS constant defined in security/smack/smack.h. Introducing
the configuration of this constant with Kconfig or cmdline might be a good
idea.

The size of the hash table was adjusted experimentally.  The rule set used by
TIZEN contains circa 17K rules for 500 labels.  The table above contains
results of SMACK initialization using 'time smackctl apply' bash command.
The 'Ref' is a kernel without this patch applied. The consecutive values
refers to value of SMACK_HASH_SLOTS.  Every measurement was repeated three
times to reduce noise.

     |  Ref  |   1   |   2   |   4   |   8   |   16  |   32  |   64  |  128  |  256  |  512
--------------------------------------------------------------------------------------------
Run1 | 1.156 | 1.096 | 0.883 | 0.764 | 0.692 | 0.667 | 0.649 | 0.633 | 0.634 | 0.629 | 0.620
Run2 | 1.156 | 1.111 | 0.885 | 0.764 | 0.694 | 0.661 | 0.649 | 0.651 | 0.634 | 0.638 | 0.623
Run3 | 1.160 | 1.107 | 0.886 | 0.764 | 0.694 | 0.671 | 0.661 | 0.638 | 0.631 | 0.624 | 0.638
AVG  | 1.157 | 1.105 | 0.885 | 0.764 | 0.693 | 0.666 | 0.653 | 0.641 | 0.633 | 0.630 | 0.627

Surprisingly, a single hlist is slightly faster than a double-linked list.
The speed-up saturates near 64 slots.  Therefore I chose value 128 to provide
some margin if more labels were used.
It looks that IO becomes a new bottleneck.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
2013-08-01 16:55:20 -07:00
Tomasz Stanislawski
470043ba99 security: smack: fix memleak in smk_write_rules_list()
The smack_parsed_rule structure is allocated.  If a rule is successfully
installed then the last reference to the object is lost.  This patch fixes this
leak. Moreover smack_parsed_rule is allocated on stack because it no longer
needed ofter smk_write_rules_list() is finished.

Signed-off-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
2013-08-01 12:57:24 -07:00
Tetsuo Handa
9548906b2b xattr: Constify ->name member of "struct xattr".
Since everybody sets kstrdup()ed constant string to "struct xattr"->name but
nobody modifies "struct xattr"->name , we can omit kstrdup() and its failure
checking by constifying ->name member of "struct xattr".

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Joel Becker <jlbec@evilplan.org> [ocfs2]
Acked-by: Serge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: Paul Moore <paul@paul-moore.com>
Tested-by: Paul Moore <paul@paul-moore.com>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2013-07-25 19:30:03 +10:00
Linus Torvalds
be0c5d8c0b NFS client updates for Linux 3.11
Feature highlights include:
 - Add basic client support for NFSv4.2
 - Add basic client support for Labeled NFS (selinux for NFSv4.2)
 - Fix the use of credentials in NFSv4.1 stateful operations, and
   add support for NFSv4.1 state protection.
 
 Bugfix highlights:
 - Fix another NFSv4 open state recovery race
 - Fix an NFSv4.1 back channel session regression
 - Various rpc_pipefs races
 - Fix another issue with NFSv3 auth negotiation
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Merge tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client updates from Trond Myklebust:
 "Feature highlights include:
   - Add basic client support for NFSv4.2
   - Add basic client support for Labeled NFS (selinux for NFSv4.2)
   - Fix the use of credentials in NFSv4.1 stateful operations, and add
     support for NFSv4.1 state protection.

  Bugfix highlights:
   - Fix another NFSv4 open state recovery race
   - Fix an NFSv4.1 back channel session regression
   - Various rpc_pipefs races
   - Fix another issue with NFSv3 auth negotiation

  Please note that Labeled NFS does require some additional support from
  the security subsystem.  The relevant changesets have all been
  reviewed and acked by James Morris."

* tag 'nfs-for-3.11-1' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: (54 commits)
  NFS: Set NFS_CS_MIGRATION for NFSv4 mounts
  NFSv4.1 Refactor nfs4_init_session and nfs4_init_channel_attrs
  nfs: have NFSv3 try server-specified auth flavors in turn
  nfs: have nfs_mount fake up a auth_flavs list when the server didn't provide it
  nfs: move server_authlist into nfs_try_mount_request
  nfs: refactor "need_mount" code out of nfs_try_mount
  SUNRPC: PipeFS MOUNT notification optimization for dying clients
  SUNRPC: split client creation routine into setup and registration
  SUNRPC: fix races on PipeFS UMOUNT notifications
  SUNRPC: fix races on PipeFS MOUNT notifications
  NFSv4.1 use pnfs_device maxcount for the objectlayout gdia_maxcount
  NFSv4.1 use pnfs_device maxcount for the blocklayout gdia_maxcount
  NFSv4.1 Fix gdia_maxcount calculation to fit in ca_maxresponsesize
  NFS: Improve legacy idmapping fallback
  NFSv4.1 end back channel session draining
  NFS: Apply v4.1 capabilities to v4.2
  NFSv4.1: Clean up layout segment comparison helper names
  NFSv4.1: layout segment comparison helpers should take 'const' parameters
  NFSv4: Move the DNS resolver into the NFSv4 module
  rpc_pipefs: only set rpc_dentry_ops if d_op isn't already set
  ...
2013-07-09 12:09:43 -07:00
David Quigley
746df9b59c Security: Add Hook to test if the particular xattr is part of a MAC model.
The interface to request security labels from user space is the xattr
interface. When requesting the security label from an NFS server it is
important to make sure the requested xattr actually is a MAC label. This allows
us to make sure that we get the desired semantics from the attribute instead of
something else such as capabilities or a time based LSM.

Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: James Morris <james.l.morris@oracle.com>
Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: Miguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: Phua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: Khin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
2013-06-08 16:20:11 -04:00
Passion,Zhao
0fcfee61d6 Smack: Fix the bug smackcipso can't set CIPSO correctly
Bug report: https://tizendev.org/bugs/browse/TDIS-3891

The reason is userspace libsmack only use "smackfs/cipso2" long-label interface,
but the code's logical is still for orginal fixed length label. Now update
smack_cipso_apply() to support flexible label (<=256 including tailing '\0')

There is also a bug in kernel/security/smack/smackfs.c:
When smk_set_cipso() parsing the CIPSO setting from userspace, the offset of
CIPSO level should be "strlen(label)+1" instead of "strlen(label)"

Signed-off-by: Passion,Zhao <passion.zhao@intel.com>
2013-06-03 10:56:02 -07:00
Tetsuo Handa
8cd77a0bd4 Smack: Fix possible NULL pointer dereference at smk_netlbl_mls()
netlbl_secattr_catmap_alloc(GFP_ATOMIC) can return NULL.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
2013-05-28 10:15:35 -07:00
Casey Schaufler
e830b39412 Smack: Add smkfstransmute mount option
Suppliment the smkfsroot mount option with another, smkfstransmute,
that does the same thing but also marks the root inode as
transmutting. This allows a freshly created filesystem to
be mounted with a transmutting heirarchy.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-05-28 10:08:44 -07:00
Casey Schaufler
2f823ff8be Smack: Improve access check performance
Each Smack label that the kernel has seen is added to a
list of labels. The list of access rules for a given subject
label hangs off of the label list entry for the label.
This patch changes the structures that contain subject
labels to point at the label list entry rather that the
label itself. Doing so removes a label list lookup in
smk_access() that was accounting for the largest single
chunk of Smack overhead.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-05-28 10:08:32 -07:00
Casey Schaufler
c673944347 Smack: Local IPv6 port based controls
Smack does not provide access controls on IPv6 communications.
This patch introduces a mechanism for maintaining Smack lables
for local IPv6 communications. It is based on labeling local ports.
The behavior should be compatible with any future "real" IPv6
support as it provides no interfaces for users to manipulate
the labeling. Remote IPv6 connections use the ambient label
the same way that unlabeled IPv4 packets are treated.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2013-05-28 10:08:26 -07:00
Casey Schaufler
958d2c2f4a Smack: include magic.h in smackfs.c
As reported for linux-next: Tree for Apr 2 (smack)
Add the required include for smackfs.c

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Reported-by: Randy Dunlap <rdunlap@infradead.org>
Acked-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2013-04-03 13:13:51 +11:00
Igor Zhbanov
cdb56b6088 Fix NULL pointer dereference in smack_inode_unlink() and smack_inode_rmdir()
This patch fixes kernel Oops because of wrong common_audit_data type
in smack_inode_unlink() and smack_inode_rmdir().

When SMACK security module is enabled and SMACK logging is on (/smack/logging
is not zero) and you try to delete the file which
1) you cannot delete due to SMACK rules and logging of failures is on
or
2) you can delete and logging of success is on,

you will see following:

	Unable to handle kernel NULL pointer dereference at virtual address 000002d7

	[<...>] (strlen+0x0/0x28)
	[<...>] (audit_log_untrustedstring+0x14/0x28)
	[<...>] (common_lsm_audit+0x108/0x6ac)
	[<...>] (smack_log+0xc4/0xe4)
	[<...>] (smk_curacc+0x80/0x10c)
	[<...>] (smack_inode_unlink+0x74/0x80)
	[<...>] (security_inode_unlink+0x2c/0x30)
	[<...>] (vfs_unlink+0x7c/0x100)
	[<...>] (do_unlinkat+0x144/0x16c)

The function smack_inode_unlink() (and smack_inode_rmdir()) need
to log two structures of different types. First of all it does:

	smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_DENTRY);
	smk_ad_setfield_u_fs_path_dentry(&ad, dentry);

This will set common audit data type to LSM_AUDIT_DATA_DENTRY
and store dentry for auditing (by function smk_curacc(), which in turn calls
dump_common_audit_data(), which is actually uses provided data and logs it).

	/*
	 * You need write access to the thing you're unlinking
	 */
	rc = smk_curacc(smk_of_inode(ip), MAY_WRITE, &ad);
	if (rc == 0) {
		/*
		 * You also need write access to the containing directory
		 */

Then this function wants to log anoter data:

		smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
		smk_ad_setfield_u_fs_inode(&ad, dir);

The function sets inode field, but don't change common_audit_data type.

		rc = smk_curacc(smk_of_inode(dir), MAY_WRITE, &ad);
	}

So the dump_common_audit() function incorrectly interprets inode structure
as dentry, and Oops will happen.

This patch reinitializes common_audit_data structures with correct type.
Also I removed unneeded
	smk_ad_setfield_u_fs_path_dentry(&ad, NULL);
initialization, because both dentry and inode pointers are stored
in the same union.

Signed-off-by: Igor Zhbanov <i.zhbanov@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
2013-03-19 14:38:17 -07:00
Rafal Krypa
e05b6f982a Smack: add support for modification of existing rules
Rule modifications are enabled via /smack/change-rule. Format is as follows:
"Subject Object rwaxt rwaxt"

First two strings are subject and object labels up to 255 characters.
Third string contains permissions to enable.
Fourth string contains permissions to disable.

All unmentioned permissions will be left unchanged.
If no rule previously existed, it will be created.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2013-03-19 14:16:42 -07:00
Jarkko Sakkinen
cee7e44334 smack: SMACK_MAGIC to include/uapi/linux/magic.h
SMACK_MAGIC moved to a proper place for easy user space access
(i.e. libsmack).

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@iki.fi>
2013-03-19 14:16:15 -07:00
Rafal Krypa
a87d79ad7c Smack: add missing support for transmute bit in smack_str_from_perm()
This fixes audit logs for granting or denial of permissions to show
information about transmute bit.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2013-03-19 14:15:41 -07:00
Rafal Krypa
d15d9fad16 Smack: prevent revoke-subject from failing when unseen label is written to it
Special file /smack/revoke-subject will silently accept labels that are not
present on the subject label list. Nothing has to be done for such labels,
as there are no rules for them to revoke.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2013-03-19 14:15:21 -07:00
Al Viro
496ad9aa8e new helper: file_inode(file)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-02-22 23:31:31 -05:00
Linus Torvalds
2a74dbb9a8 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security
Pull security subsystem updates from James Morris:
 "A quiet cycle for the security subsystem with just a few maintenance
  updates."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security:
  Smack: create a sysfs mount point for smackfs
  Smack: use select not depends in Kconfig
  Yama: remove locking from delete path
  Yama: add RCU to drop read locking
  drivers/char/tpm: remove tasklet and cleanup
  KEYS: Use keyring_alloc() to create special keyrings
  KEYS: Reduce initial permissions on keys
  KEYS: Make the session and process keyrings per-thread
  seccomp: Make syscall skipping and nr changes more consistent
  key: Fix resource leak
  keys: Fix unreachable code
  KEYS: Add payload preparsing opportunity prior to key instantiate or update
2012-12-16 15:40:50 -08:00
Casey Schaufler
e930723741 Smack: create a sysfs mount point for smackfs
There are a number of "conventions" for where to put LSM filesystems.
Smack adheres to none of them. Create a mount point at /sys/fs/smackfs
for mounting smackfs so that Smack can be conventional.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-12-14 10:57:23 -08:00
Casey Schaufler
111fe8bd65 Smack: use select not depends in Kconfig
The components NETLABEL and SECURITY_NETWORK are required by
Smack. Using "depends" in Kconfig hides the Smack option
if the user hasn't figured out that they need to be enabled
while using make menuconfig. Using select is a better choice.
Because select is not recursive depends on NET and SECURITY
are added. The reflects similar usage in TOMOYO and AppArmor.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-12-14 10:57:10 -08:00
Al Viro
808d4e3cfd consitify do_mount() arguments
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-10-11 20:02:04 -04:00
Casey Schaufler
46a2f3b9e9 Smack: setprocattr memory leak fix
The data structure allocations being done in prepare_creds
are duplicated in smack_setprocattr. This results in the
structure allocated in prepare_creds being orphaned and
never freed. The duplicate code is removed from
smack_setprocattr.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-09-18 09:51:06 -07:00
Rafal Krypa
449543b043 Smack: implement revoking all rules for a subject label
Add /smack/revoke-subject special file. Writing a SMACK label to this file will
set the access to '-' for all access rules with that subject label.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
2012-09-18 09:50:52 -07:00
Casey Schaufler
c00bedb368 Smack: remove task_wait() hook.
On 12/20/2011 11:20 PM, Jarkko Sakkinen wrote:
> Allow SIGCHLD to be passed to child process without
> explicit policy. This will help to keep the access
> control policy simple and easily maintainable with
> complex applications that require use of multiple
> security contexts. It will also help to keep them
> as isolated as possible.
>
> Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>

I have a slightly different version that applies to the
current smack-next tree.

Allow SIGCHLD to be passed to child process without
explicit policy. This will help to keep the access
control policy simple and easily maintainable with
complex applications that require use of multiple
security contexts. It will also help to keep them
as isolated as possible.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>

 security/smack/smack_lsm.c |   37 ++++++++-----------------------------
 1 files changed, 8 insertions(+), 29 deletions(-)
2012-09-18 09:50:37 -07:00
Alan Cox
3b9fc37280 smack: off by one error
Consider the input case of a rule that consists entirely of non space
symbols followed by a \0. Say 64 + \0

In this case strlen(data) = 64
kzalloc of subject and object are 64 byte objects
sscanfdata, "%s %s %s", subject, ...)

will put 65 bytes into subject.

Signed-off-by: Alan Cox <alan@linux.intel.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-07-30 15:04:17 +10:00
Rafal Krypa
65ee7f45cf Smack: don't show empty rules when /smack/load or /smack/load2 is read
This patch removes empty rules (i.e. with access set to '-') from the
rule list presented to user space.

Smack by design never removes labels nor rules from its lists. Access
for a rule may be set to '-' to effectively disable it. Such rules would
show up in the listing generated when /smack/load or /smack/load2 is
read. This may cause clutter if many rules were disabled.

As a rule with access set to '-' is equivalent to no rule at all, they
may be safely hidden from the listing.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Rafal Krypa <r.krypa@samsung.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-07-13 15:49:24 -07:00
Casey Schaufler
3518721a89 Smack: user access check bounds
Some of the bounds checking used on the /smack/access
interface was lost when support for long labels was
added. No kernel access checks are affected, however
this is a case where /smack/access could be used
incorrectly and fail to detect the error. This patch
reintroduces the original checks.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-07-13 15:49:24 -07:00
Casey Schaufler
1880eff77e Smack: onlycap limits on CAP_MAC_ADMIN
Smack is integrated with the POSIX capabilities scheme,
using the capabilities CAP_MAC_OVERRIDE and CAP_MAC_ADMIN to
determine if a process is allowed to ignore Smack checks or
change Smack related data respectively. Smack provides an
additional restriction that if an onlycap value is set
by writing to /smack/onlycap only tasks with that Smack
label are allowed to use CAP_MAC_OVERRIDE.

This change adds CAP_MAC_ADMIN as a capability that is affected
by the onlycap mechanism.

Targeted for git://git.gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-07-13 15:49:23 -07:00
Casey Schaufler
eb982cb4cf Smack: fix smack_new_inode bogosities
In January of 2012 Al Viro pointed out three bits of code that
he titled "new_inode_smack bogosities". This patch repairs these
errors.

1. smack_sb_kern_mount() included a NULL check that is impossible.
   The check and NULL case are removed.
2. smack_kb_kern_mount() included pointless locking. The locking is
   removed. Since this is the only place that lock was used the lock
   is removed from the superblock_smack structure.
3. smk_fill_super() incorrectly and unnecessarily set the Smack label
   for the smackfs root inode. The assignment has been removed.

Targeted for git://gitorious.org/smack-next/kernel.git

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-07-13 15:49:23 -07:00
Al Viro
e5467859f7 split ->file_mmap() into ->mmap_addr()/->mmap_file()
... i.e. file-dependent and address-dependent checks.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-31 13:11:54 -04:00
Al Viro
d007794a18 split cap_mmap_addr() out of cap_file_mmap()
... switch callers.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-05-31 13:10:54 -04:00
James Morris
ff2bb047c4 Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next
Per pull request, for 3.5.
2012-05-22 11:21:06 +10:00
Casey Schaufler
f7112e6c9a Smack: allow for significantly longer Smack labels v4
V4 updated to current linux-security#next
Targeted for git://gitorious.org/smack-next/kernel.git

Modern application runtime environments like to use
naming schemes that are structured and generated without
human intervention. Even though the Smack limit of 23
characters for a label name is perfectly rational for
human use there have been complaints that the limit is
a problem in environments where names are composed from
a set or sources, including vendor, author, distribution
channel and application name. Names like

	softwarehouse-pgwodehouse-coolappstore-mellowmuskrats

are becoming harder to avoid. This patch introduces long
label support in Smack. Labels are now limited to 255
characters instead of the old 23.

The primary reason for limiting the labels to 23 characters
was so they could be directly contained in CIPSO category sets.
This is still done were possible, but for labels that are too
large a mapping is required. This is perfectly safe for communication
that stays "on the box" and doesn't require much coordination
between boxes beyond what would have been required to keep label
names consistent.

The bulk of this patch is in smackfs, adding and updating
administrative interfaces. Because existing APIs can't be
changed new ones that do much the same things as old ones
have been introduced.

The Smack specific CIPSO data representation has been removed
and replaced with the data format used by netlabel. The CIPSO
header is now computed when a label is imported rather than
on use. This results in improved IP performance. The smack
label is now allocated separately from the containing structure,
allowing for larger strings.

Four new /smack interfaces have been introduced as four
of the old interfaces strictly required labels be specified
in fixed length arrays.

The access interface is supplemented with the check interface:
	access  "Subject                 Object                  rwxat"
	access2 "Subject Object rwaxt"

The load interface is supplemented with the rules interface:
	load   "Subject                 Object                  rwxat"
	load2  "Subject Object rwaxt"

The load-self interface is supplemented with the self-rules interface:
	load-self   "Subject                 Object                  rwxat"
	load-self2  "Subject Object rwaxt"

The cipso interface is supplemented with the wire interface:
	cipso  "Subject                  lvl cnt  c1  c2 ..."
	cipso2 "Subject lvl cnt  c1  c2 ..."

The old interfaces are maintained for compatibility.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-05-14 22:48:38 -07:00
Tetsuo Handa
ceffec5541 gfp flags for security_inode_alloc()?
Dave Chinner wrote:
> Yes, because you have no idea what the calling context is except
> for the fact that is from somewhere inside filesystem code and the
> filesystem could be holding locks. Therefore, GFP_NOFS is really the
> only really safe way to allocate memory here.

I see. Thank you.

I'm not sure, but can call trace happen where somewhere inside network
filesystem or stackable filesystem code with locks held invokes operations that
involves GFP_KENREL memory allocation outside that filesystem?
----------
[PATCH] SMACK: Fix incorrect GFP_KERNEL usage.

new_inode_smack() which can be called from smack_inode_alloc_security() needs
to use GFP_NOFS like SELinux's inode_alloc_security() does, for
security_inode_alloc() is called from inode_init_always() and
inode_init_always() is called from xfs_inode_alloc() which is using GFP_NOFS.

smack_inode_init_security() needs to use GFP_NOFS like
selinux_inode_init_security() does, for initxattrs() callback function (e.g.
btrfs_initxattrs()) which is called from security_inode_init_security() is
using GFP_NOFS.

smack_audit_rule_match() needs to use GFP_ATOMIC, for
security_audit_rule_match() can be called from audit_filter_user_rules() and
audit_filter_user_rules() is called from audit_filter_user() with RCU read lock
held.

Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>
2012-05-14 22:47:44 -07:00
Casey Schaufler
2267b13a7c Smack: recursive tramsmute
The transmuting directory feature of Smack requires that
the transmuting attribute be explicitly set in all cases.
It seems the users of this facility would expect that the
transmuting attribute be inherited by subdirectories that
are created in a transmuting directory. This does not seem
to add any additional complexity to the understanding of
how the system works.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2012-05-14 22:45:17 -07:00
Casey Schaufler
86812bb0de Smack: move label list initialization
A kernel with Smack enabled will fail if tmpfs has xattr support.

Move the initialization of predefined Smack label
list entries to the LSM initialization from the
smackfs setup. This became an issue when tmpfs
acquired xattr support, but was never correct.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <james.l.morris@oracle.com>
2012-04-18 12:02:28 +10:00
Kees Cook
923e9a1399 Smack: build when CONFIG_AUDIT not defined
This fixes builds where CONFIG_AUDIT is not defined and
CONFIG_SECURITY_SMACK=y.

This got introduced by the stack-usage reducation commit 48c62af68a
("LSM: shrink the common_audit_data data union").

Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-10 16:14:40 -07:00
Eric Paris
50c205f5e5 LSM: do not initialize common_audit_data to 0
It isn't needed.  If you don't set the type of the data associated with
that type it is a pretty obvious programming bug.  So why waste the cycles?

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:23:04 -04:00
Eric Paris
83d498569e SELinux: rename dentry_open to file_open
dentry_open takes a file, rename it to file_open

Signed-off-by: Eric Paris <eparis@redhat.com>
2012-04-09 12:22:50 -04:00
Linus Torvalds
b61c37f579 lsm_audit: don't specify the audit pre/post callbacks in 'struct common_audit_data'
It just bloats the audit data structure for no good reason, since the
only time those fields are filled are just before calling the
common_lsm_audit() function, which is also the only user of those
fields.

So just make them be the arguments to common_lsm_audit(), rather than
bloating that structure that is passed around everywhere, and is
initialized in hot paths.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03 09:49:59 -07:00
Eric Paris
48c62af68a LSM: shrink the common_audit_data data union
After shrinking the common_audit_data stack usage for private LSM data I'm
not going to shrink the data union.  To do this I'm going to move anything
larger than 2 void * ptrs to it's own structure and require it to be declared
separately on the calling stack.  Thus hot paths which don't need more than
a couple pointer don't have to declare space to hold large unneeded
structures.  I could get this down to one void * by dealing with the key
struct and the struct path.  We'll see if that is helpful after taking care of
networking.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03 09:49:10 -07:00
Eric Paris
3b3b0e4fc1 LSM: shrink sizeof LSM specific portion of common_audit_data
Linus found that the gigantic size of the common audit data caused a big
perf hit on something as simple as running stat() in a loop.  This patch
requires LSMs to declare the LSM specific portion separately rather than
doing it in a union.  Thus each LSM can be responsible for shrinking their
portion and don't have to pay a penalty just because other LSMs have a
bigger space requirement.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-03 09:48:40 -07:00
Al Viro
4040153087 security: trim security.h
Trim security.h

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: James Morris <jmorris@namei.org>
2012-02-14 10:45:42 +11:00
Al Viro
d8c9584ea2 vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-06 23:16:53 -05:00
Casey Schaufler
40809565ca Smack: smackfs cipso seq read repair
Commit 272cd7a8c6 introduced
a change to the way rule lists are handled and reported in
the smackfs filesystem. One of the issues addressed had to
do with the termination of read requests on /smack/load.
This change introduced a error in /smack/cipso, which shares
some of the same list processing code.

This patch updates all the file access list handling in
smackfs to use the code introduced for /smack/load.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-11-11 11:07:21 -08:00
Jarkko Sakkinen
0e94ae17c8 Smack: allow to access /smack/access as normal user
Allow query access as a normal user removing the need
for CAP_MAC_ADMIN. Give RW access to /smack/access
for UGO. Do not import smack labels in access check.

Signed-off-by: Jarkko Sakkinen <jarkko.j.sakkinen@gmail.com>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>
2011-10-20 16:07:31 -07:00
Jarkko Sakkinen
d86b2b61d4 Smack: fix: invalid length set for the result of /smack/access
Forgot to update simple_transaction_set() to take terminator
character into account.

Signed-off-by: Jarkko Sakkinen <jarkko.j.sakkinen@gmail.com>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>
2011-10-18 09:02:57 -07:00
Jarkko Sakkinen
16014d8750 Smack: compilation fix
On some build configurations PER_CLEAR_ON_SETID symbol was not
found when compiling smack_lsm.c. This patch fixes the issue by
explicitly doing #include <linux/personality.h>.

Signed-off-by: Jarkko Sakkinen <jarkko.j.sakkinen@gmail.com>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>
2011-10-14 08:56:49 -07:00
Jarkko Sakkinen
f8859d98c1 Smack: fix for /smack/access output, use string instead of byte
Small fix for the output of access SmackFS file. Use string
is instead of byte. Makes it easier to extend API if it is
needed.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
2011-10-12 14:30:07 -07:00
Jarkko Sakkinen
84088ba239 Smack: domain transition protections (v3)
Protections for domain transition:

- BPRM unsafe flags
- Secureexec
- Clear unsafe personality bits.
- Clear parent death signal

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
2011-10-12 14:28:15 -07:00
Casey Schaufler
975d5e55c2 Smack: Provide information for UDS getsockopt(SO_PEERCRED)
This patch is targeted for the smack-next tree.

This patch takes advantage of the recent changes for performance
and points the packet labels on UDS connect at the output label of
the far side. This makes getsockopt(...SO_PEERCRED...) function
properly. Without this change the getsockopt does not provide any
information.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-10-12 14:27:05 -07:00
Casey Schaufler
ce8a432197 Smack: Clean up comments
There are a number of comments in the Smack code that
are either malformed or include code. This patch cleans
them up.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-10-12 14:26:07 -07:00
Casey Schaufler
531f1d453e Smack: Repair processing of fcntl
Al Viro pointed out that the processing of fcntl done
by Smack appeared poorly designed. He was right. There
are three things that required change. Most obviously,
the list of commands that really imply writing is limited
to those involving file locking and signal handling.
The initialization if the file security blob was
incomplete, requiring use of a heretofore unused LSM hook.
Finally, the audit information coming from a helper
masked the identity of the LSM hook. This patch corrects
all three of these defects.

This is targeted for the smack-next tree pending comments.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-10-12 14:24:28 -07:00
Casey Schaufler
272cd7a8c6 Smack: Rule list lookup performance
This patch is targeted for the smack-next tree.

Smack access checks suffer from two significant performance
issues. In cases where there are large numbers of rules the
search of the single list of rules is wasteful. Comparing the
string values of the smack labels is less efficient than a
numeric comparison would.

These changes take advantage of the Smack label list, which
maintains the mapping of Smack labels to secids and optional
CIPSO labels. Because the labels are kept perpetually, an
access check can be done strictly based on the address of the
label in the list without ever looking at the label itself.
Rather than keeping one global list of rules the rules with
a particular subject label can be based off of that label
list entry. The access check need never look at entries that
do not use the current subject label.

This requires that packets coming off the network with
CIPSO direct Smack labels that have never been seen before
be treated carefully. The only case where they could be
delivered is where the receiving socket has an IPIN star
label, so that case is explicitly addressed.

On a system with 39,800 rules (200 labels in all permutations)
a system with this patch runs an access speed test in 5% of
the time of the old version. That should be a best case
improvement. If all of the rules are associated with the
same subject label and all of the accesses are for processes
with that label (unlikely) the improvement is about 30%.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-10-12 14:23:13 -07:00
Jarkko Sakkinen
828716c28f Smack: check permissions from user space (v2)
Adds a new file into SmackFS called 'access'. Wanted
Smack permission is written into /smack/access.
After that result can be read from the opened file.
If access applies result contains 1 and otherwise
0. File access is protected from race conditions
by using simple_transaction_get()/set() API.

Fixes from the previous version:
- Removed smack.h changes, refactoring left-over
from previous version.
- Removed #include <linux/smack.h>, refactoring
left-over from previous version.

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@intel.com>
Signed-off-by: Casey Schaufler <cschaufler@cschaufler-intel.(none)>
2011-10-12 14:21:32 -07:00
Paul Moore
82c21bfab4 doc: Update the email address for Paul Moore in various source files
My @hp.com will no longer be valid starting August 5, 2011 so an update is
necessary.  My new email address is employer independent so we don't have
to worry about doing this again any time soon.

Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: Paul Moore <paul@paul-moore.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-01 17:58:33 -07:00
Al Viro
e74f71eb78 ->permission() sanitizing: don't pass flags to ->inode_permission()
pass that via mask instead.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-07-20 01:43:26 -04:00
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
Eric Paris
92f4250901 SMACK: smack_file_lock can use the struct path
smack_file_lock has a struct path, so use that instead of only the
dentry.

Signed-off-by: Eric Paris <eparis@redhat.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
2011-04-25 18:14:45 -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
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
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
Lucas De Marchi
25985edced Fix common misspellings
Fixes generated by 'codespell' and manually reviewed.

Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
2011-03-31 11:26:23 -03:00
James Morris
fe3fa43039 Merge branch 'master' of git://git.infradead.org/users/eparis/selinux into next 2011-03-08 11:38:10 +11:00
Casey Schaufler
75a25637bf Smack: correct final mmap check comparison
The mmap policy enforcement checks the access of the
SMACK64MMAP subject against the current subject incorrectly.
The check as written works correctly only if the access
rules involved have the same access. This is the common
case, so initial testing did not find a problem.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-02-09 19:58:42 -08:00
Shan Wei
db904aa814 security:smack: kill unused SMACK_LIST_MAX, MAY_ANY and MAY_ANYWRITE
Kill unused macros of SMACK_LIST_MAX, MAY_ANY and MAY_ANYWRITE.
v2: As Casey Schaufler's advice, also remove MAY_ANY.

Signed-off-by: Shan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-02-09 19:58:11 -08:00
Casey Schaufler
0e0a070d3a Smack: correct behavior in the mmap hook
The mmap policy enforcement was not properly handling the
  interaction between the global and local rule lists.
  Instead of going through one and then the other, which
  missed the important case where a rule specified that
  there should be no access, combine the access limitations
  where there is a rule in each list.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2011-02-09 18:50:23 +11:00
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
Casey Schaufler
7898e1f8e9 Subject: [PATCH] Smack: mmap controls for library containment
In the embedded world there are often situations
  where libraries are updated from a variety of sources,
  for a variety of reasons, and with any number of
  security characteristics. These differences
  might include privilege required for a given library
  provided interface to function properly, as occurs
  from time to time in graphics libraries. There are
  also cases where it is important to limit use of
  libraries based on the provider of the library and
  the security aware application may make choices
  based on that criteria.

  These issues are addressed by providing an additional
  Smack label that may optionally be assigned to an object,
  the SMACK64MMAP attribute. An mmap operation is allowed
  if there is no such attribute.

  If there is a SMACK64MMAP attribute the mmap is permitted
  only if a subject with that label has all of the access
  permitted a subject with the current task label.

  Security aware applications may from time to time
  wish to reduce their "privilege" to avoid accidental use
  of privilege. One case where this arises is the
  environment in which multiple sources provide libraries
  to perform the same functions. An application may know
  that it should eschew services made available from a
  particular vendor, or of a particular version.

  In support of this a secondary list of Smack rules has
  been added that is local to the task. This list is
  consulted only in the case where the global list has
  approved access. It can only further restrict access.
  Unlike the global last, if no entry is found on the
  local list access is granted. An application can add
  entries to its own list by writing to /smack/load-self.

  The changes appear large as they involve refactoring
  the list handling to accomodate there being more
  than one rule list.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2011-01-17 08:05:27 -08:00
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
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
Jarkko Sakkinen
5c6d1125f8 Smack: Transmute labels on specified directories
In a situation where Smack access rules allow processes
with multiple labels to write to a directory it is easy
to get into a situation where the directory gets cluttered
with files that the owner can't deal with because while
they could be written to the directory a process at the
label of the directory can't write them. This is generally
the desired behavior, but when it isn't it is a real
issue.

This patch introduces a new attribute SMACK64TRANSMUTE that
instructs Smack to create the file with the label of the directory
under certain circumstances.

A new access mode, "t" for transmute, is made available to
Smack access rules, which are expanded from "rwxa" to "rwxat".
If a file is created in a directory marked as transmutable
and if access was granted to perform the operation by a rule
that included the transmute mode, then the file gets the
Smack label of the directory instead of the Smack label of the
creating process.

Note that this is equivalent to creating an empty file at the
label of the directory and then having the other process write
to it. The transmute scheme requires that both the access rule
allows transmutation and that the directory be explicitly marked.

Signed-off-by: Jarkko Sakkinen <ext-jarkko.2.sakkinen@nokia.com>
Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
2010-12-07 14:04:02 -08:00
Casey Schaufler
676dac4b1b This patch adds a new security attribute to Smack called
SMACK64EXEC. It defines label that is used while task is
running.

Exception: in smack_task_wait() child task is checked
for write access to parent task using label inherited
from the task that forked it.

Fixed issues from previous submit:
- SMACK64EXEC was not read when SMACK64 was not set.
- inode security blob was not updated after setting
  SMACK64EXEC
- inode security blob was not updated when removing
  SMACK64EXEC
2010-12-02 06:43:39 -08:00
Casey Schaufler
b4e0d5f079 Smack: UDS revision
This patch addresses a number of long standing issues
    with the way Smack treats UNIX domain sockets.

    All access control was being done based on the label of
    the file system object. This is inconsistant with the
    internet domain, in which access is done based on the
    IPIN and IPOUT attributes of the socket. As a result
    of the inode label policy it was not possible to use
    a UDS socket for label cognizant services, including
    dbus and the X11 server.

    Support for SCM_PEERSEC on UDS sockets is also provided.

Signed-off-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-11-29 09:04:35 +11:00
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
Al Viro
fc14f2fef6 convert get_sb_single() users
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2010-10-29 04:16:28 -04:00
Linus Torvalds
092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Eric Paris
d5630b9d27 security: secid_to_secctx returns len when data is NULL
With the (long ago) interface change to have the secid_to_secctx functions
do the string allocation instead of having the caller do the allocation we
lost the ability to query the security server for the length of the
upcoming string.  The SECMARK code would like to allocate a netlink skb
with enough length to hold the string but it is just too unclean to do the
string allocation twice or to do the allocation the first time and hold
onto the string and slen.  This patch adds the ability to call
security_secid_to_secctx() with a NULL data pointer and it will just set
the slen pointer.

Signed-off-by: Eric Paris <eparis@redhat.com>
Reviewed-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: James Morris <jmorris@namei.org>
2010-10-21 10:12:50 +11:00