The 54e70ec5 commit introduced a
bidirectional check that should have checked for mutual WRITE access
between two labels. Due to a typo the second check was incorrect.
Signed-off-by: NLukasz Pawelczyk <l.pawelczyk@samsung.com>

Signed-off-by: NLukasz Pawelczyk <l.pawelczyk@samsung.com>

People keep asking me for permissive mode, and I keep saying "no".

Permissive mode is wrong for more reasons than I can enumerate,
but the compelling one is that it's once on, never off.

Nonetheless, there is an argument to be made for running a
process with lots of permissions, logging which are required,
and then locking the process down. There wasn't a way to do
that with Smack, but this provides it.

The notion is that you start out by giving the process an
appropriate Smack label, such as "ATBirds". You create rules
with a wide range of access and the "b" mode. On Tizen it
might be:

	ATBirds	System	rwxalb
	ATBirds	User	rwxalb
	ATBirds	_	rwxalb
	User	ATBirds	wb
	System	ATBirds	wb

Accesses that fail will generate audit records. Accesses
that succeed because of rules marked with a "b" generate
log messages identifying the rule, the program and as much
object information as is convenient.

When the system is properly configured and the programs
brought in line with the labeling scheme the "b" mode can
be removed from the rules. When the system is ready for
production the facility can be configured out.

This provides the developer the convenience of permissive
mode without creating a system that looks like it is
enforcing a policy while it is not.
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

While opening with CAP_MAC_OVERRIDE file label is not set.
Other calls may access it after CAP_MAC_OVERRIDE is dropped from process.
Signed-off-by: NMarcin Niesluchowski <m.niesluchow@samsung.com>

Values of extended attributes are stored as binary blobs. NULL-termination
of them isn't required. It just wastes disk space and confuses command-line
tools like getfattr because they have to print that zero byte at the end.

This patch removes terminating zero byte from initial security label in
smack_inode_init_security and cuts it out in function smack_inode_getsecurity
which is used by syscall getxattr. This change seems completely safe, because
function smk_parse_smack ignores everything after first zero byte.
Signed-off-by: NKonstantin Khlebnikov <k.khlebnikov@samsung.com>

Zero-length security labels are invalid but kernel should handle them.

This patch fixes kernel panic after setting zero-length security labels:
# attr -S -s "SMACK64" -V "" file

And after writing zero-length string into smackfs files syslog and onlycp:
# python -c 'import os; os.write(1, "")' > /smack/syslog

The problem is caused by brain-damaged logic in function smk_parse_smack()
which takes pointer to buffer and its length but if length below or equal zero
it thinks that the buffer is zero-terminated. Unfortunately callers of this
function are widely used and proper fix requires serious refactoring.
Signed-off-by: NKonstantin Khlebnikov <k.khlebnikov@samsung.com>

Security operation ->inode_listsecurity is used for generating list of
available extended attributes for syscall listxattr. Currently it's used
only in nfs4 or if filesystem doesn't provide i_op->listxattr.

The list is the set of NULL-terminated names, one after the other.
This method must include zero byte at the and into result.

Also this function must return length even if string does not fit into
output buffer or it is NULL, see similar method in selinux and man listxattr.
Signed-off-by: NKonstantin Khlebnikov <k.khlebnikov@samsung.com>

Historically the NetLabel LSM secattr catmap functions and data
structures have had very long names which makes a mess of the NetLabel
code and anyone who uses NetLabel.  This patch renames the catmap
functions and structures from "*_secattr_catmap_*" to just "*_catmap_*"
which improves things greatly.

There are no substantial code or logic changes in this patch.
Signed-off-by: NPaul Moore <pmoore@redhat.com>
Tested-by: NCasey Schaufler <casey@schaufler-ca.com>

The cgroup filesystem isn't ready for an LSM to
properly use extented attributes. This patch makes
files created in the cgroup filesystem usable by
a system running Smack and systemd.

Targeted for git://git.gitorious.org/smack-next/kernel.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Smack believes that many of the operatons that can
be performed on an open file descriptor are read operations.
The fstat and lseek system calls are examples.
An implication of this is that files shouldn't be open
if the task doesn't have read access even if it has
write access and the file is being opened write only.

Targeted for git://git.gitorious.org/smack-next/kernel.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Smack IPC policy requires that the sender have write access
to the receiver. UDS streams don't do per-packet checks. The
only check is done at connect time. The existing code checks
if the connecting process can write to the other, but not the
other way around. This change adds a check that the other end
can write to the connecting process.

Targeted for git://git.gitorious.org/smack-next/kernel.gitSigned-off-by: NCasey Schuafler <casey@schaufler-ca.com>

Sam Henderson points out that removing the SMACK64TRANSMUTE
attribute from a directory does not result in the directory
transmuting. This is because the inode flag indicating that
the directory is transmuting isn't cleared. The fix is a tad
less than trivial because smk_task and smk_mmap should have
been broken out, too.

Targeted for git://git.gitorious.org/smack-next/kernel.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

The function `smack_inode_post_setxattr` is called each
time that a setxattr is done, for any value of name.
The kernel allow to put value==NULL when size==0
to set an empty attribute value. The systematic
call to smk_import_entry was causing the dereference
of a NULL pointer hence a KERNEL PANIC!

The problem can be produced easily by issuing the
command `setfattr -n user.data file` under bash prompt
when SMACK is active.

Moving the call to smk_import_entry as proposed by this
patch is correcting the behaviour because the function
smack_inode_post_setxattr is called for the SMACK's
attributes only if the function smack_inode_setxattr validated
the value and its size (what will not be the case when size==0).

It also has a benefical effect to not fill the smack hash
with garbage values coming from any extended attribute
write.

Change-Id: Iaf0039c2be9bccb6cee11c24a3b44d209101fe47
Signed-off-by: NJosé Bollo <jose.bollo@open.eurogiciel.org>

1. In order to remove any SMACK extended attribute from a file, a user
should have CAP_MAC_ADMIN capability. But user without having this
capability is able to remove SMACK64MMAP security attribute.

2. While validating size and value of smack extended attribute in
smack_inode_setsecurity hook, wrong error code is returned.
Signed-off-by: NPankaj Kumar <pamkaj.k2@samsung.com>
Signed-off-by: NHimanshu Shukla <himanshu.sh@samsung.com>

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: NLukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: NRafal Krypa <r.krypa@samsung.com>

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: NLukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: NRafal Krypa <r.krypa@samsung.com>

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: NLukasz Pawelczyk <l.pawelczyk@partner.samsung.com>
Signed-off-by: NRafal Krypa <r.krypa@samsung.com>

Fix a possible memory access fault when transmute is true and isp is NULL.
Signed-off-by: NJosé Bollo <jose.bollo@open.eurogiciel.org>

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: NDmitry Kasatkin <d.kasatkin@samsung.com>
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>

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: NDavid Howells <dhowells@redhat.com>
Tested-by: NDmitry Kasatkin <d.kasatkin@samsung.com>

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: NRichard Guy Briggs <rgb@redhat.com>
Signed-off-by: NEric Paris <eparis@redhat.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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: NTomasz Stanislawski <t.stanislaws@samsung.com>

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: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Reviewed-by: Joel Becker <jlbec@evilplan.org> [ocfs2]
Acked-by: NSerge E. Hallyn <serge.hallyn@ubuntu.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Acked-by: NMimi Zohar <zohar@linux.vnet.ibm.com>
Reviewed-by: NPaul Moore <paul@paul-moore.com>
Tested-by: NPaul Moore <paul@paul-moore.com>
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

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: NEric Paris <eparis@redhat.com>
Acked-by: NJames Morris <james.l.morris@oracle.com>
Signed-off-by: NMatthew N. Dodd <Matthew.Dodd@sparta.com>
Signed-off-by: NMiguel Rodel Felipe <Rodel_FM@dsi.a-star.edu.sg>
Signed-off-by: NPhua Eu Gene <PHUA_Eu_Gene@dsi.a-star.edu.sg>
Signed-off-by: NKhin Mi Mi Aung <Mi_Mi_AUNG@dsi.a-star.edu.sg>
Signed-off-by: NTrond Myklebust <Trond.Myklebust@netapp.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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: NIgor Zhbanov <i.zhbanov@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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.gitSigned-off-by: NCasey Schaufler <casey@schaufler-ca.com>

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: NCasey Schaufler <casey@schaufler-ca.com>

 security/smack/smack_lsm.c |   37 ++++++++-----------------------------
 1 files changed, 8 insertions(+), 29 deletions(-)