At some point I think I messed up and dropped the calls to netlbl_skbuff_err()
which are necessary for CIPSO to send error notifications to remote systems.
This patch re-introduces the error handling calls into the SELinux code.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NJames Morris <jmorris@namei.org>

Currently when SELinux fails to allocate memory in
security_netlbl_sid_to_secattr() the NetLabel LSM domain field is set to
NULL which triggers the default NetLabel LSM domain mapping which may not
always be the desired mapping.  This patch fixes this by returning an error
when the kernel is unable to allocate memory.  This could result in more
failures on a system with heavy memory pressure but it is the "correct"
thing to do.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NJames Morris <jmorris@namei.org>

It turns out that checking to see if skb->sk is NULL is not a very good
indicator of a forwarded packet as some locally generated packets also have
skb->sk set to NULL.  Fix this by not only checking the skb->sk field but also
the IP[6]CB(skb)->flags field for the IP[6]SKB_FORWARDED flag.  While we are
at it, we are calling selinux_parse_skb() much earlier than we really should
resulting in potentially wasted cycles parsing packets for information we
might no use; so shuffle the code around a bit to fix this.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NJames Morris <jmorris@namei.org>

We did the right thing in a few cases but there were several areas where we
determined a packet's address family based on the socket's address family which
is not the right thing to do since we can get IPv4 packets on IPv6 sockets.
This patch fixes these problems by either taking the address family directly
from the packet.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NJames Morris <jmorris@namei.org>

We were doing a lot of extra work in selinux_netlbl_sock_graft() what wasn't
necessary so this patch removes that code.  It also removes the redundant
second argument to selinux_netlbl_sock_setsid() which allows us to simplify a
few other functions.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Acked-by: NJames Morris <jmorris@namei.org>

At some point during the 2.6.27 development cycle two new fields were added
to the SELinux context structure, a string pointer and a length field.  The
code in selinux_secattr_to_sid() was not modified and as a result these two
fields were left uninitialized which could result in erratic behavior,
including kernel panics, when NetLabel is used.  This patch fixes the
problem by fully initializing the context in selinux_secattr_to_sid() before
use and reducing the level of direct context manipulation done to help
prevent future problems.

Please apply this to the 2.6.27-rcX release stream.
Signed-off-by: NPaul Moore <paul.moore@hp.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix a bug and a philosophical decision about who handles errors.

security_context_to_sid_core() was leaking a context in the common case.
This was causing problems on fedora systems which recently have started
making extensive use of this function.

In discussion it was decided that if string_to_context_struct() had an
error it was its own responsibility to clean up any mess it created
along the way.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix the setting of PF_SUPERPRIV by __capable() as it could corrupt the flags
the target process if that is not the current process and it is trying to
change its own flags in a different way at the same time.

__capable() is using neither atomic ops nor locking to protect t->flags.  This
patch removes __capable() and introduces has_capability() that doesn't set
PF_SUPERPRIV on the process being queried.

This patch further splits security_ptrace() in two:

 (1) security_ptrace_may_access().  This passes judgement on whether one
     process may access another only (PTRACE_MODE_ATTACH for ptrace() and
     PTRACE_MODE_READ for /proc), and takes a pointer to the child process.
     current is the parent.

 (2) security_ptrace_traceme().  This passes judgement on PTRACE_TRACEME only,
     and takes only a pointer to the parent process.  current is the child.

     In Smack and commoncap, this uses has_capability() to determine whether
     the parent will be permitted to use PTRACE_ATTACH if normal checks fail.
     This does not set PF_SUPERPRIV.

Two of the instances of __capable() actually only act on current, and so have
been changed to calls to capable().

Of the places that were using __capable():

 (1) The OOM killer calls __capable() thrice when weighing the killability of a
     process.  All of these now use has_capability().

 (2) cap_ptrace() and smack_ptrace() were using __capable() to check to see
     whether the parent was allowed to trace any process.  As mentioned above,
     these have been split.  For PTRACE_ATTACH and /proc, capable() is now
     used, and for PTRACE_TRACEME, has_capability() is used.

 (3) cap_safe_nice() only ever saw current, so now uses capable().

 (4) smack_setprocattr() rejected accesses to tasks other than current just
     after calling __capable(), so the order of these two tests have been
     switched and capable() is used instead.

 (5) In smack_file_send_sigiotask(), we need to allow privileged processes to
     receive SIGIO on files they're manipulating.

 (6) In smack_task_wait(), we let a process wait for a privileged process,
     whether or not the process doing the waiting is privileged.

I've tested this with the LTP SELinux and syscalls testscripts.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Acked-by: NAndrew G. Morgan <morgan@kernel.org>
Acked-by: NAl Viro <viro@zeniv.linux.org.uk>
Signed-off-by: NJames Morris <jmorris@namei.org>

Given a hosed SELinux config in which a system never loads policy or
disables SELinux we currently just return -EINVAL for anyone trying to
read /proc/mounts.  This is a configuration problem but we can certainly
be more graceful.  This patch just ignores -EINVAL when displaying LSM
options and causes /proc/mounts display everything else it can.  If
policy isn't loaded the obviously there are no options, so we aren't
really loosing any information here.

This is safe as the only other return of EINVAL comes from
security_sid_to_context_core() in the case of an invalid sid.  Even if a
FS was mounted with a now invalidated context that sid should have been
remapped to unlabeled and so we won't hit the EINVAL and will work like
we should.  (yes, I tested to make sure it worked like I thought)
Signed-off-by: NEric Paris <eparis@redhat.com>
Tested-by: NMarc Dionne <marc.c.dionne@gmail.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

... and get rid of the last "let's deduce mask from nameidata->flags"
bit.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAlexey Dobriyan <adobriyan@gmail.com>
Acked-by: NJames Morris <jmorris@namei.org>
Signed-off-by: NPatrick McHardy <kaber@trash.net>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This adds the tracehook_tracer_task() hook to consolidate all forms of
"Who is using ptrace on me?" logic.  This is used for "TracerPid:" in
/proc and for permission checks.  We also clean up the selinux code the
called an identical accessor.
Signed-off-by: NRoland McGrath <roland@redhat.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Reviewed-by: NIngo Molnar <mingo@elte.hu>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This reverts commit 811f3799.

From Eric Paris:

"Please drop this patch for now.  It deadlocks on ntfs-3g.  I need to
rework it to handle fuse filesystems better.  (casey was right)"

The register security hook is no longer required, as the capability
module is always registered.  LSMs wishing to stack capability as
a secondary module should do so explicitly.
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NGreg Kroah-Hartman <gregkh@suse.de>

The sb_get_mnt_opts() hook is unused, and is superseded by the
sb_show_options() hook.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Acked-by: NJames Morris <jmorris@namei.org>

This patch causes SELinux mount options to show up in /proc/mounts.  As
with other code in the area seq_put errors are ignored.  Other LSM's
will not have their mount options displayed until they fill in their own
security_sb_show_options() function.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NJames Morris <jmorris@namei.org>

Currently if a FS is mounted for which SELinux policy does not define an
fs_use_* that FS will either be genfs labeled or not labeled at all.
This decision is based on the existence of a genfscon rule in policy and
is irrespective of the capabilities of the filesystem itself.  This
patch allows the kernel to check if the filesystem supports security
xattrs and if so will use those if there is no fs_use_* rule in policy.
An fstype with a no fs_use_* rule but with a genfs rule will use xattrs
if available and will follow the genfs rule.

This can be particularly interesting for things like ecryptfs which
actually overlays a real underlying FS.  If we define excryptfs in
policy to use xattrs we will likely get this wrong at times, so with
this path we just don't need to define it!

Overlay ecryptfs on top of NFS with no xattr support:
SELinux: initialized (dev ecryptfs, type ecryptfs), uses genfs_contexts
Overlay ecryptfs on top of ext4 with xattr support:
SELinux: initialized (dev ecryptfs, type ecryptfs), uses xattr

It is also useful as the kernel adds new FS we don't need to add them in
policy if they support xattrs and that is how we want to handle them.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Use do_each_thread as a proper do/while block.  Sparse complained.
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>

Remove unused and shadowed addrlen variable.  Picked up by sparse.
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NPaul Moore <paul.moore@hp.com>

I've gotten complaints and reports about people not understanding the
meaning of the current unknown class/perm handling the kernel emits on
every policy load.  Hopefully this will make make it clear to everyone
the meaning of the message and won't waste a printk the user won't care
about anyway on systems where the kernel and the policy agree on
everything.
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

On Mon, 2008-06-09 at 01:24 -0700, Andrew Morton wrote:
> Getting a few of these with FC5:
>
> SELinux: context_struct_compute_av:  unrecognized class 69
> SELinux: context_struct_compute_av:  unrecognized class 69
>
> one came out when I logged in.
>
> No other symptoms, yet.

Change handling of invalid classes by SELinux, reporting class values
unknown to the kernel as errors (w/ ratelimit applied) and handling
class values unknown to policy as normal denials.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

We used to protect against races of policy load in security_load_policy
by using the load_mutex.  Since then we have added a new mutex,
sel_mutex, in sel_write_load() which is always held across all calls to
security_load_policy we are covered and can safely just drop this one.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

The class_to_string array is referenced by tclass.  My code mistakenly
was using tclass - 1.  If the proceeding class is a userspace class
rather than kernel class this may cause a denial/EINVAL even if unknown
handling is set to allow.  The bug shouldn't be allowing excess
privileges since those are given based on the contents of another array
which should be correctly referenced.

At this point in time its pretty unlikely this is going to cause
problems.  The most recently added kernel classes which could be
affected are association, dccp_socket, and peer.  Its pretty unlikely
any policy with handle_unknown=allow doesn't have association and
dccp_socket undefined (they've been around longer than unknown handling)
and peer is conditionalized on a policy cap which should only be defined
if that class exists in policy.
Signed-off-by: NEric Paris <eparis@redhat.com>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Open code sidtab lock to make Andrew Morton happy.
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>

Open code load_mutex as suggested by Andrew Morton.
Signed-off-by: NJames Morris <jmorris@namei.org>

Open code policy_rwlock, as suggested by Andrew Morton.
Signed-off-by: NJames Morris <jmorris@namei.org>
Acked-by: NStephen Smalley <sds@tycho.nsa.gov>

Fix an endianness bug in the handling of network node addresses by
SELinux.  This yields no change on little endian hardware but fixes
the incorrect handling on big endian hardware.  The network node
addresses are stored in network order in memory by checkpolicy, not in
cpu/host order, and thus should not have cpu_to_le32/le32_to_cpu
conversions applied upon policy write/read unlike other data in the
policy.

Bug reported by John Weeks of Sun, who noticed that binary policy
files built from the same policy source on x86 and sparc differed and
tracked it down to the ipv4 address handling in checkpolicy.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Simplify and improve the robustness of the SELinux ioctl checking by
using the "access mode" bits of the ioctl command to determine the
permission check rather than dealing with individual command values.
This removes any knowledge of specific ioctl commands from SELinux
and follows the same guidance we gave to Smack earlier.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Enable processes with CAP_MAC_ADMIN + mac_admin permission in policy
to get undefined contexts on inodes.  This extends the support for
deferred mapping of security contexts in order to permit restorecon
and similar programs to see the raw file contexts unknown to the
system policy in order to check them.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Enable security modules to distinguish reading of process state via
proc from full ptrace access by renaming ptrace_may_attach to
ptrace_may_access and adding a mode argument indicating whether only
read access or full attach access is requested.  This allows security
modules to permit access to reading process state without granting
full ptrace access.  The base DAC/capability checking remains unchanged.

Read access to /proc/pid/mem continues to apply a full ptrace attach
check since check_mem_permission() already requires the current task
to already be ptracing the target.  The other ptrace checks within
proc for elements like environ, maps, and fds are changed to pass the
read mode instead of attach.

In the SELinux case, we model such reading of process state as a
reading of a proc file labeled with the target process' label.  This
enables SELinux policy to permit such reading of process state without
permitting control or manipulation of the target process, as there are
a number of cases where programs probe for such information via proc
but do not need to be able to control the target (e.g. procps,
lsof, PolicyKit, ConsoleKit).  At present we have to choose between
allowing full ptrace in policy (more permissive than required/desired)
or breaking functionality (or in some cases just silencing the denials
via dontaudit rules but this can hide genuine attacks).

This version of the patch incorporates comments from Casey Schaufler
(change/replace existing ptrace_may_attach interface, pass access
mode), and Chris Wright (provide greater consistency in the checking).

Note that like their predecessors __ptrace_may_attach and
ptrace_may_attach, the __ptrace_may_access and ptrace_may_access
interfaces use different return value conventions from each other (0
or -errno vs. 1 or 0).  I retained this difference to avoid any
changes to the caller logic but made the difference clearer by
changing the latter interface to return a bool rather than an int and
by adding a comment about it to ptrace.h for any future callers.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Acked-by: NChris Wright <chrisw@sous-sol.org>
Signed-off-by: NJames Morris <jmorris@namei.org>

Remove inherit field from inode_security_struct, per Stephen Smalley:
"Let's just drop inherit altogether - dead field."
Signed-off-by: NJames Morris <jmorris@namei.org>

reorder inode_security_struct to remove padding on 64 bit builds

size reduced from 72 to 64 bytes increasing objects per slab to 64.
Signed-off-by: NRichard Kennedy <richard@rsk.demon.co.uk>
Signed-off-by: NJames Morris <jmorris@namei.org>

Formatting and syntax changes

whitespace, tabs to spaces, trailing space
put open { on same line as struct def
remove unneeded {} after if statements
change printk("Lu") to printk("llu")
convert asm/uaccess.h to linux/uaacess.h includes
remove unnecessary asm/bug.h includes
convert all users of simple_strtol to strict_strtol
Signed-off-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Fix a sleeping function called from invalid context bug by moving allocation
to the callers prior to taking the policy rdlock.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Introduce SELinux support for deferred mapping of security contexts in
the SID table upon policy reload, and use this support for inode
security contexts when the context is not yet valid under the current
policy.  Only processes with CAP_MAC_ADMIN + mac_admin permission in
policy can set undefined security contexts on inodes.  Inodes with
such undefined contexts are treated as having the unlabeled context
until the context becomes valid upon a policy reload that defines the
context.  Context invalidation upon policy reload also uses this
support to save the context information in the SID table and later
recover it upon a subsequent policy reload that defines the context
again.

This support is to enable package managers and similar programs to set
down file contexts unknown to the system policy at the time the file
is created in order to better support placing loadable policy modules
in packages and to support build systems that need to create images of
different distro releases with different policies w/o requiring all of
the contexts to be defined or legal in the build host policy.

With this patch applied, the following sequence is possible, although
in practice it is recommended that this permission only be allowed to
specific program domains such as the package manager.

# rmdir baz
# rm bar
# touch bar
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument
# cat setundefined.te
policy_module(setundefined, 1.0)
require {
	type unconfined_t;
	type unlabeled_t;
}
files_type(unlabeled_t)
allow unconfined_t self:capability2 mac_admin;
# make -f /usr/share/selinux/devel/Makefile setundefined.pp
# semodule -i setundefined.pp
# chcon -t foo_exec_t bar # foo_exec_t is not yet defined
# mkdir -Z system_u:object_r:foo_exec_t baz
# ls -Zd bar baz
-rw-r--r--  root root system_u:object_r:unlabeled_t    bar
drwxr-xr-x  root root system_u:object_r:unlabeled_t    baz
# cat foo.te
policy_module(foo, 1.0)
type foo_exec_t;
files_type(foo_exec_t)
# make -f /usr/share/selinux/devel/Makefile foo.pp
# semodule -i foo.pp # defines foo_exec_t
# ls -Zd bar baz
-rw-r--r--  root root user_u:object_r:foo_exec_t       bar
drwxr-xr-x  root root system_u:object_r:foo_exec_t    baz
# semodule -r foo
# ls -Zd bar baz
-rw-r--r--  root root system_u:object_r:unlabeled_t    bar
drwxr-xr-x  root root system_u:object_r:unlabeled_t    baz
# semodule -i foo.pp
# ls -Zd bar baz
-rw-r--r--  root root user_u:object_r:foo_exec_t       bar
drwxr-xr-x  root root system_u:object_r:foo_exec_t    baz
# semodule -r setundefined foo
# chcon -t foo_exec_t bar # no longer defined and not allowed
chcon: failed to change context of `bar' to `system_u:object_r:foo_exec_t': Invalid argument
# rmdir baz
# mkdir -Z system_u:object_r:foo_exec_t baz
mkdir: failed to set default file creation context to `system_u:object_r:foo_exec_t': Invalid argument
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <jmorris@namei.org>

Initial splitoff of the low-level stuff; taken to fdtable.h
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Every implementation of ->task_kill() does nothing when the signal comes from
the kernel.  This is correct, but means that check_kill_permission() should
call security_task_kill() only for SI_FROMUSER() case, and we can remove the
same check from ->task_kill() implementations.

(sadly, check_kill_permission() is the last user of signal->session/__session
 but we can't s/task_session_nr/task_session/ here).

NOTE: Eric W.  Biederman pointed out cap_task_kill() should die, and I think
he is very right.
Signed-off-by: NOleg Nesterov <oleg@tv-sign.ru>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Roland McGrath <roland@redhat.com>
Cc: Casey Schaufler <casey@schaufler-ca.com>
Cc: David Quigley <dpquigl@tycho.nsa.gov>
Cc: Eric Paris <eparis@redhat.com>
Cc: Harald Welte <laforge@gnumonks.org>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Make secctx_to_secid() take constant secdata.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NJames Morris <jmorris@namei.org>

Make secctx_to_secid() take constant secdata.
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

Don't generate the per-UID user and user session keyrings unless they're
explicitly accessed.  This solves a problem during a login process whereby
set*uid() is called before the SELinux PAM module, resulting in the per-UID
keyrings having the wrong security labels.

This also cures the problem of multiple per-UID keyrings sometimes appearing
due to PAM modules (including pam_keyinit) setuiding and causing user_structs
to come into and go out of existence whilst the session keyring pins the user
keyring.  This is achieved by first searching for extant per-UID keyrings
before inventing new ones.

The serial bound argument is also dropped from find_keyring_by_name() as it's
not currently made use of (setting it to 0 disables the feature).
Signed-off-by: NDavid Howells <dhowells@redhat.com>
Cc: <kwc@citi.umich.edu>
Cc: <arunsr@cse.iitk.ac.in>
Cc: <dwalsh@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: James Morris <jmorris@namei.org>
Cc: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>