In this patch we're sending an ICMPv6 message to a peer to
immediately inform it that making a connection is not possible.
In case of TCP connections, without this change, the peer
will be waiting until a connection timeout is exceeded.
Signed-off-by: NPiotr Sawicki <p.sawicki2@partner.samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

The smack_socket_sock_rcv_skb() function is checking smack labels
only for UDP and TCP frames carried in IPv6 packets. From now on,
it is able also to handle UDP-Lite and DCCP protocols.
Signed-off-by: NPiotr Sawicki <p.sawicki2@partner.samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

A socket which has sk_family set to PF_INET6 is able to receive not
only IPv6 but also IPv4 traffic (IPv4-mapped IPv6 addresses).

Prior to this patch, the smk_skb_to_addr_ipv6() could have been
called for socket buffers containing IPv4 packets, in result such
traffic was allowed.
Signed-off-by: NPiotr Sawicki <p.sawicki2@partner.samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Acked-by: NLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Smack: Mark inode instant in smack_task_to_inode

/proc clean-up in commit 1bbc5513
resulted in smack_task_to_inode() being called before smack_d_instantiate.
This resulted in the smk_inode value being ignored, even while present
for files in /proc/self. Marking the inode as instant here fixes that.
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

Fix memory leak in smack_inode_getsecctx

The implementation of smack_inode_getsecctx() made
incorrect assumptions about how Smack presents a security
context. Smack does not need to allocate memory to support
security contexts, so "releasing" a Smack context is a no-op.
The code made an unnecessary copy and returned that as a
context, which was never freed. The revised implementation
returns the context correctly.
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
Reported-by: NCHANDAN VN <chandan.vn@samsung.com>
Tested-by: NCHANDAN VN <chandan.vn@samsung.com>

Make sure to implement the new socketpair callback so the SO_PEERSEC
call on socketpair(2)s will return correct information.
Signed-off-by: NTom Gundersen <teg@jklm.no>
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

There is a permission discrepancy when consulting msq ipc object
metadata between /proc/sysvipc/msg (0444) and the MSG_STAT shmctl
command.  The later does permission checks for the object vs S_IRUGO.
As such there can be cases where EACCESS is returned via syscall but the
info is displayed anyways in the procfs files.

While this might have security implications via info leaking (albeit no
writing to the msq metadata), this behavior goes way back and showing
all the objects regardless of the permissions was most likely an
overlook - so we are stuck with it.  Furthermore, modifying either the
syscall or the procfs file can cause userspace programs to break (ie
ipcs).  Some applications require getting the procfs info (without root
privileges) and can be rather slow in comparison with a syscall -- up to
500x in some reported cases for shm.

This patch introduces a new MSG_STAT_ANY command such that the msq ipc
object permissions are ignored, and only audited instead.  In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.

Link: http://lkml.kernel.org/r/20180215162458.10059-4-dave@stgolabs.netSigned-off-by: NDavidlohr Bueso <dbueso@suse.de>
Reported-by: NRobert Kettler <robert.kettler@outlook.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

There is a permission discrepancy when consulting shm ipc object
metadata between /proc/sysvipc/sem (0444) and the SEM_STAT semctl
command.  The later does permission checks for the object vs S_IRUGO.
As such there can be cases where EACCESS is returned via syscall but the
info is displayed anyways in the procfs files.

While this might have security implications via info leaking (albeit no
writing to the sma metadata), this behavior goes way back and showing
all the objects regardless of the permissions was most likely an
overlook - so we are stuck with it.  Furthermore, modifying either the
syscall or the procfs file can cause userspace programs to break (ie
ipcs).  Some applications require getting the procfs info (without root
privileges) and can be rather slow in comparison with a syscall -- up to
500x in some reported cases for shm.

This patch introduces a new SEM_STAT_ANY command such that the sem ipc
object permissions are ignored, and only audited instead.  In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.

Link: http://lkml.kernel.org/r/20180215162458.10059-3-dave@stgolabs.netSigned-off-by: NDavidlohr Bueso <dbueso@suse.de>
Reported-by: NRobert Kettler <robert.kettler@outlook.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Patch series "sysvipc: introduce STAT_ANY commands", v2.

The following patches adds the discussed (see [1]) new command for shm
as well as for sems and msq as they are subject to the same
discrepancies for ipc object permission checks between the syscall and
via procfs.  These new commands are justified in that (1) we are stuck
with this semantics as changing syscall and procfs can break userland;
and (2) some users can benefit from performance (for large amounts of
shm segments, for example) from not having to parse the procfs
interface.

Once merged, I will submit the necesary manpage updates.  But I'm thinking
something like:

: diff --git a/man2/shmctl.2 b/man2/shmctl.2
: index 7bb503999941..bb00bbe21a57 100644
: --- a/man2/shmctl.2
: +++ b/man2/shmctl.2
: @@ -41,6 +41,7 @@
:  .\" 2005-04-25, mtk -- noted aberrant Linux behavior w.r.t. new
:  .\"	attaches to a segment that has already been marked for deletion.
:  .\" 2005-08-02, mtk: Added IPC_INFO, SHM_INFO, SHM_STAT descriptions.
: +.\" 2018-02-13, dbueso: Added SHM_STAT_ANY description.
:  .\"
:  .TH SHMCTL 2 2017-09-15 "Linux" "Linux Programmer's Manual"
:  .SH NAME
: @@ -242,6 +243,18 @@ However, the
:  argument is not a segment identifier, but instead an index into
:  the kernel's internal array that maintains information about
:  all shared memory segments on the system.
: +.TP
: +.BR SHM_STAT_ANY " (Linux-specific)"
: +Return a
: +.I shmid_ds
: +structure as for
: +.BR SHM_STAT .
: +However, the
: +.I shm_perm.mode
: +is not checked for read access for
: +.IR shmid ,
: +resembing the behaviour of
: +/proc/sysvipc/shm.
:  .PP
:  The caller can prevent or allow swapping of a shared
:  memory segment with the following \fIcmd\fP values:
: @@ -287,7 +300,7 @@ operation returns the index of the highest used entry in the
:  kernel's internal array recording information about all
:  shared memory segments.
:  (This information can be used with repeated
: -.B SHM_STAT
: +.B SHM_STAT/SHM_STAT_ANY
:  operations to obtain information about all shared memory segments
:  on the system.)
:  A successful
: @@ -328,7 +341,7 @@ isn't accessible.
:  \fIshmid\fP is not a valid identifier, or \fIcmd\fP
:  is not a valid command.
:  Or: for a
: -.B SHM_STAT
: +.B SHM_STAT/SHM_STAT_ANY
:  operation, the index value specified in
:  .I shmid
:  referred to an array slot that is currently unused.

This patch (of 3):

There is a permission discrepancy when consulting shm ipc object metadata
between /proc/sysvipc/shm (0444) and the SHM_STAT shmctl command.  The
later does permission checks for the object vs S_IRUGO.  As such there can
be cases where EACCESS is returned via syscall but the info is displayed
anyways in the procfs files.

While this might have security implications via info leaking (albeit no
writing to the shm metadata), this behavior goes way back and showing all
the objects regardless of the permissions was most likely an overlook - so
we are stuck with it.  Furthermore, modifying either the syscall or the
procfs file can cause userspace programs to break (ie ipcs).  Some
applications require getting the procfs info (without root privileges) and
can be rather slow in comparison with a syscall -- up to 500x in some
reported cases.

This patch introduces a new SHM_STAT_ANY command such that the shm ipc
object permissions are ignored, and only audited instead.  In addition,
I've left the lsm security hook checks in place, as if some policy can
block the call, then the user has no other choice than just parsing the
procfs file.

[1] https://lkml.org/lkml/2017/12/19/220

Link: http://lkml.kernel.org/r/20180215162458.10059-2-dave@stgolabs.netSigned-off-by: NDavidlohr Bueso <dbueso@suse.de>
Acked-by: NMichal Hocko <mhocko@suse.com>
Cc: Michael Kerrisk <mtk.manpages@gmail.com>
Cc: Manfred Spraul <manfred@colorfullife.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Robert Kettler <robert.kettler@outlook.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Rename the variables shp, sma, msq to isp. As that is how the code already
refers to those variables.

Collapse smack_of_shm, smack_of_sem, and smack_of_msq into smack_of_ipc,
as the three functions had become completely identical.

Collapse smack_shm_alloc_security, smack_sem_alloc_security and
smack_msg_queue_alloc_security into smack_ipc_alloc_security as the three
functions had become identical.

Collapse smack_shm_free_security, smack_sem_free_security and
smack_msg_queue_free_security into smack_ipc_free_security as the
three functions had become identical.
Requested-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

For IMA purposes, we want to be able to obtain the prepared secid in the
bprm structure before the credentials are committed. Add a cred_getsecid
hook that makes this possible.
Signed-off-by: NMatthew Garrett <mjg59@google.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NMimi Zohar <zohar@linux.vnet.ibm.com>

All of the implementations of security hooks that take msg_queue only
access q_perm the struct kern_ipc_perm member.  This means the
dependencies of the msg_queue security hooks can be simplified by
passing the kern_ipc_perm member of msg_queue.

Making this change will allow struct msg_queue to become private to
ipc/msg.c.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

All of the implementations of security hooks that take shmid_kernel only
access shm_perm the struct kern_ipc_perm member.  This means the
dependencies of the shm security hooks can be simplified by passing
the kern_ipc_perm member of shmid_kernel..

Making this change will allow struct shmid_kernel to become private to ipc/shm.c.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

All of the implementations of security hooks that take sem_array only
access sem_perm the struct kern_ipc_perm member.  This means the
dependencies of the sem security hooks can be simplified by passing
the kern_ipc_perm member of sem_array.

Making this change will allow struct sem and struct sem_array
to become private to ipc/sem.c.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

usb, signal, security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill

commit d178bc3a ("user namespace: usb:
 make usb urbs user namespace aware (v2)") changed kill_pid_info_as_uid
to kill_pid_info_as_cred, saving and passing a cred structure instead of
uids.  Since the secid can be obtained from the cred, drop the secid fields
from the usb_dev_state and async structures, and drop the secid argument to
kill_pid_info_as_cred.  Replace the secid argument to security_task_kill
with the cred.  Update SELinux, Smack, and AppArmor to use the cred, which
avoids the need for Smack and AppArmor to use a secid at all in this hook.
Further changes to Smack might still be required to take full advantage of
this change, since it should now be possible to perform capability
checking based on the supplied cred.  The changes to Smack and AppArmor
have only been compile-tested.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NPaul Moore <paul@paul-moore.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Acked-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <james.morris@microsoft.com>

The new file system CGROUP2 isn't actually handled
by smack. This changes makes Smack treat equally
CGROUP and CGROUP2 items.
Signed-off-by: NJosé Bollo <jose.bollo@iot.bzh>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Smack: Privilege check on key operations

Operations on key objects are subjected to Smack policy
even if the process is privileged. This is inconsistent
with the general behavior of Smack and may cause issues
with authentication by privileged daemons. This patch
allows processes with CAP_MAC_OVERRIDE to access keys
even if the Smack rules indicate otherwise.
Reported-by: NJose Bollo <jobol@nonadev.net>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

This patch fixes the warning reported by smatch:
security/smack/smack_lsm.c:2872 smack_socket_connect() warn:
variable dereferenced before check 'sock->sk' (see line 2869)
Signed-off-by: NVasyl Gomonovych <gomonovych@gmail.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Supply the Smack module hooks in support of overlayfs.
Ensure that the Smack label of new files gets the correct
value when a directory is transmuting. Original implementation
by Romanini Daniele, with a few tweaks added.
Signed-off-by: NRomanini Daniele <daniele.romanini@aalto.fi>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

security_inode_getsecurity() provides the text string value
of a security attribute. It does not provide a "secctx".
The code in xattr_getsecurity() that calls security_inode_getsecurity()
and then calls security_release_secctx() happened to work because
SElinux and Smack treat the attribute and the secctx the same way.
It fails for cap_inode_getsecurity(), because that module has no
secctx that ever needs releasing. It turns out that Smack is the
one that's doing things wrong by not allocating memory when instructed
to do so by the "alloc" parameter.

The fix is simple enough. Change the security_release_secctx() to
kfree() because it isn't a secctx being returned by
security_inode_getsecurity(). Change Smack to allocate the string when
told to do so.

Note: this also fixes memory leaks for LSMs which implement
inode_getsecurity but not release_secctx, such as capabilities.
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
Reported-by: NKonstantin Khlebnikov <khlebnikov@yandex-team.ru>
Cc: stable@vger.kernel.org
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

This removes the redundant pdeath_signal clearing in Smack: the check in
smack_bprm_committing_creds() matches the check in smack_bprm_set_creds()
(which used to be in the now-removed smack_bprm_securexec() hook) and
since secureexec is now being checked for clearing pdeath_signal, this
is redundant to the common exec code.
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Reviewed-by: NJames Morris <james.l.morris@oracle.com>
Reviewed-by: NCasey Schaufler <casey@schaufler-ca.com>

The Smack bprm_secureexec hook can be merged with the bprm_set_creds
hook since it's dealing with the same information, and all of the details
are finalized during the first call to the bprm_set_creds hook via
prepare_binprm() (subsequent calls due to binfmt_script, etc, are ignored
via bprm->called_set_creds).

Here, the test can just happen at the end of the bprm_set_creds hook,
and the bprm_secureexec hook can be dropped.
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Reviewed-by: NJames Morris <james.l.morris@oracle.com>
Reviewed-by: NCasey Schaufler <casey@schaufler-ca.com>

The cred_prepared bprm flag has a misleading name. It has nothing to do
with the bprm_prepare_cred hook, and actually tracks if bprm_set_creds has
been called. Rename this flag and improve its comment.

Cc: David Howells <dhowells@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Acked-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NJames Morris <james.l.morris@oracle.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Acked-by: NSerge Hallyn <serge@hallyn.com>

The check of S_ISSOCK() in smack_file_receive() is not
appropriate if the passed descriptor is a socket.
Reported-by: NStephen Smalley <sds@tyco.nsa.gov>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

smack_parse_opts_str() calls kfree(opts->mnt_opts) when kcalloc() for
opts->mnt_opts_flags failed. But it should not have called it because
security_free_mnt_opts() will call kfree(opts->mnt_opts).
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
fixes: 3bf2789c ("smack: allow mount opts setting over filesystems with binary mount data")
Cc: Vivek Trivedi <t.vivek@samsung.com>
Cc: Amit Sahrawat <a.sahrawat@samsung.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>

Mark all of the registration hooks as __ro_after_init (via the
__lsm_ro_after_init macro).
Signed-off-by: NJames Morris <james.l.morris@oracle.com>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NKees Cook <keescook@chromium.org>

With previous changes every location that tests for
LSM_UNSAFE_PTRACE_CAP also tests for LSM_UNSAFE_PTRACE making the
LSM_UNSAFE_PTRACE_CAP redundant, so remove it.
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

I am still tired of having to find indirect ways to determine
what security modules are active on a system. I have added
/sys/kernel/security/lsm, which contains a comma separated
list of the active security modules. No more groping around
in /proc/filesystems or other clever hacks.

Unchanged from previous versions except for being updated
to the latest security next branch.
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
Acked-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NPaul Moore <paul@paul-moore.com>
Acked-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

As reported by yangshukui, a permission denial from security_task_wait()
can lead to a soft lockup in zap_pid_ns_processes() since it only expects
sys_wait4() to return 0 or -ECHILD. Further, security_task_wait() can
in general lead to zombies; in the absence of some way to automatically
reparent a child process upon a denial, the hook is not useful.  Remove
the security hook and its implementations in SELinux and Smack.  Smack
already removed its check from its hook.
Reported-by: Nyangshukui <yangshukui@huawei.com>
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Acked-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NPaul Moore <paul@paul-moore.com>

The access to fd from anon_inode is always failed because there is
no set xattr operations. So this patch fixes to ignore private
inode including anon_inode for file functions.

It was only ignored for smack_file_receive() to share dma-buf fd,
but dma-buf has other functions like ioctl and mmap.

Reference: https://lkml.org/lkml/2015/4/17/16Signed-off-by: NSeung-Woo Kim <sw0312.kim@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Since 4b936885 (v2.6.32) all inodes on sockfs and pipefs are disconnected.
It caused filesystem specific code in smack_d_instantiate to be skipped,
because all inodes on those pseudo filesystems were treated as root inodes.
As a result all sockfs inodes had the Smack label set to floor.

In most cases access checks for sockets use socket_smack data so the inode
label is not important. But there are special cases that were broken.
One example would be calling fcntl with F_SETOWN command on a socket fd.

Now smack_d_instantiate expects all pipefs and sockfs inodes to be
disconnected and has the logic in appropriate place.
Signed-off-by: NRafal Krypa <r.krypa@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

smack_file_open() is first checking the capability of calling subject,
this check will skip the SMACK logging for success case. Use smk_tskacc()
for proper logging and SMACK access check.
Signed-off-by: NHimanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

In smack_from_secattr function,"smack_known_list" is being traversed
using list_for_each_entry macro, although it is a rcu protected
structure. So it should be traversed using "list_for_each_entry_rcu"
macro to fetch the rcu protected entry.
Signed-off-by: NVishal Goel <vishal.goel@samsung.com>
Signed-off-by: NHimanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

There is race condition issue while freeing the i_security blob in SMACK
module. There is existing condition where i_security can be freed while
inode_permission is called from path lookup on second CPU. There has been
observed the page fault with such condition. VFS code and Selinux module
takes care of this condition by freeing the inode and i_security field
using RCU via call_rcu(). But in SMACK directly the i_secuirty blob is
being freed. Use call_rcu() to fix this race condition issue.
Signed-off-by: NHimanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: NVishal Goel <vishal.goel@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

smk_copy_rules() and smk_copy_relabel() are initializing list_head though
they have been initialized already in new_task_smack() function. Delete
repeated initialization.
Signed-off-by: NHimanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Fix the issue of wrong SMACK label (SMACK64IPIN) update when a second bind
call is made to same IP address & port, but with different SMACK label
(SMACK64IPIN) by second instance of server. In this case server returns
with "Bind:Address already in use" error but before returning, SMACK label
is updated in SMACK port-label mapping list inside smack_socket_bind() hook

To fix this issue a new check has been added in smk_ipv6_port_label()
function before updating the existing port entry. It checks whether the
socket for matching port entry is closed or not. If it is closed then it
means port is not bound and it is safe to update the existing port entry
else return if port is still getting used. For checking whether socket is
closed or not, one more field "smk_can_reuse" has been added in the
"smk_port_label" structure. This field will be set to '1' in
"smack_sk_free_security()" function which is called to free the socket
security blob when the socket is being closed. In this function, port entry
is searched in the SMACK port-label mapping list for the closing socket.
If entry is found then "smk_can_reuse" field is set to '1'.Initially
"smk_can_reuse" field is set to '0' in smk_ipv6_port_label() function after
creating a new entry in the list which indicates that socket is in use.
Signed-off-by: NVishal Goel <vishal.goel@samsung.com>
Signed-off-by: NHimanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Permission denied error comes when 2 IPv6 servers are running and client
tries to connect one of them. Scenario is that both servers are using same
IP and port but different protocols(Udp and tcp). They are using different
SMACK64IPIN labels.Tcp server is using "test" and udp server is using
"test-in". When we try to run tcp client with SMACK64IPOUT label as "test",
then connection denied error comes. It should not happen since both tcp
server and client labels are same.This happens because there is no check
for protocol in smk_ipv6_port_label() function while searching for the
earlier port entry. It checks whether there is an existing port entry on
the basis of port only. So it updates the earlier port entry in the list.
Due to which smack label gets changed for earlier entry in the
"smk_ipv6_port_list" list and permission denied error comes.

Now a check is added for socket type also.Now if 2 processes use same
port  but different protocols (tcp or udp), then 2 different port entries
will be  added in the list. Similarly while checking smack access in
smk_ipv6_port_check() function,  port entry is searched on the basis of
both port and protocol.
Signed-off-by: NVishal Goel <vishal.goel@samsung.com>
Signed-off-by: NHimanshu Shukla <Himanshu.sh@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Add the rcu synchronization mechanism for accessing smk_ipv6_port_list
in smack IPv6 hooks. Access to the port list is vulnerable to a race
condition issue,it does not apply proper synchronization methods while
working on critical section. It is possible that when one thread is
reading the list, at the same time another thread is modifying the
same port list, which can cause the major problems.

To ensure proper synchronization between two threads, rcu mechanism
has been applied while accessing and modifying the port list. RCU will
also not affect the performance, as there are more accesses than
modification where RCU is most effective synchronization mechanism.
Signed-off-by: NVishal Goel <vishal.goel@samsung.com>
Signed-off-by: NHimanshu Shukla <himanshu.sh@samsung.com>
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>

Processes can only alter their own security attributes via
/proc/pid/attr nodes.  This is presently enforced by each individual
security module and is also imposed by the Linux credentials
implementation, which only allows a task to alter its own credentials.
Move the check enforcing this restriction from the individual
security modules to proc_pid_attr_write() before calling the security hook,
and drop the unnecessary task argument to the security hook since it can
only ever be the current task.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Acked-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NPaul Moore <paul@paul-moore.com>