linux-toradex.git/security/smack/smack.h, branch v3.14.56

Smack: Make the syslog control configurable

2013-12-23T23:50:55+00:00

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

Smack: Implement lock security mode

2013-10-18T16:39:33+00:00

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

Smack: network label match fix

2013-08-02T03:04:02+00:00

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

security: smack: add a hash table to quicken smk_find_entry()

2013-08-01T23:55:20+00:00

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

Smack: Add smkfstransmute mount option

2013-05-28T17:08:44+00:00

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

Smack: Improve access check performance

2013-05-28T17:08:32+00:00

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

Smack: Local IPv6 port based controls

2013-05-28T17:08:26+00:00

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

smack: SMACK_MAGIC to include/uapi/linux/magic.h

2013-03-19T21:16:15+00:00

SMACK_MAGIC moved to a proper place for easy user space access
(i.e. libsmack).

Signed-off-by: Jarkko Sakkinen

Smack: onlycap limits on CAP_MAC_ADMIN

2012-07-13T22:49:23+00:00

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

Smack: fix smack_new_inode bogosities

2012-07-13T22:49:23+00:00

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