Since seccomp transitions between threads requires updates to the
no_new_privs flag to be atomic, the flag must be part of an atomic flag
set. This moves the nnp flag into a separate task field, and introduces
accessors.
Signed-off-by: NKees Cook <keescook@chromium.org>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Reviewed-by: NAndy Lutomirski <luto@amacapital.net>

Unless task == current ptrace_parent(task) is not safe even under
rcu_read_lock() and most of the current users are not right.

So may_change_ptraced_domain(task) looks wrong as well. However it
is always called with task == current so the code is actually fine.
Remove this argument to make this fact clear.

Note: perhaps we should simply kill ptrace_parent(), it buys almost
nothing. And it is obviously racy, perhaps this should be fixed.
Signed-off-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Mediation is based off of the cred but auditing includes the current
task which may not be related to the actual request.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Allow emulating the default profile behavior from boot, by allowing
loading of a profile in the unconfined state into a new NS.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

ns->unconfined is being used read side without locking, nor rcu but is
being updated when a namespace is removed. This works for the root ns
which is never removed but has a race window and can cause failures when
children namespaces are removed.

Also ns and ns->unconfined have a circular refcounting dependency that
is problematic and must be broken. Currently this is done incorrectly
when the namespace is destroyed.

Fix this by forward referencing unconfined via the replacedby infrastructure
instead of directly updating the ns->unconfined pointer.

Remove the circular refcount dependency by making the ns and its unconfined
profile share the same refcount.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

remove the use of replaced by chaining and move to profile invalidation
and lookup to handle task replacement.

Replacement chaining can result in large chains of profiles being pinned
in memory when one profile in the chain is use. With implicit labeling
this will be even more of a problem, so move to a direct lookup method.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSeth Arnold <seth.arnold@canonical.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSteve Beattie <sbeattie@ubuntu.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSteve Beattie <sbeattie@ubuntu.com>

Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-By: NSteve Beattie <sbeattie@ubuntu.com>

When policy specifies a transition to a profile that is not currently
loaded, it result in exec being denied.  However the failure is not being
audited correctly because the audit code is treating this as an allowed
permission and thus not reporting it.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-By: NSteve Beattie <sbeattie@ubuntu.com>

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

Cc: John Johansen <john.johansen@canonical.com>
Acked-by: NSerge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

Add support for AppArmor to explicitly fail requested domain transitions
if NO_NEW_PRIVS is set and the task is not unconfined.

Transitions from unconfined are still allowed because this always results
in a reduction of privileges.
Acked-by: NEric Paris <eparis@redhat.com>
Signed-off-by: NWill Drewry <wad@chromium.org>
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>

v18: new acked-by, new description
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

With this change, calling
  prctl(PR_SET_NO_NEW_PRIVS, 1, 0, 0, 0)
disables privilege granting operations at execve-time.  For example, a
process will not be able to execute a setuid binary to change their uid
or gid if this bit is set.  The same is true for file capabilities.

Additionally, LSM_UNSAFE_NO_NEW_PRIVS is defined to ensure that
LSMs respect the requested behavior.

To determine if the NO_NEW_PRIVS bit is set, a task may call
  prctl(PR_GET_NO_NEW_PRIVS, 0, 0, 0, 0);
It returns 1 if set and 0 if it is not set. If any of the arguments are
non-zero, it will return -1 and set errno to -EINVAL.
(PR_SET_NO_NEW_PRIVS behaves similarly.)

This functionality is desired for the proposed seccomp filter patch
series.  By using PR_SET_NO_NEW_PRIVS, it allows a task to modify the
system call behavior for itself and its child tasks without being
able to impact the behavior of a more privileged task.

Another potential use is making certain privileged operations
unprivileged.  For example, chroot may be considered "safe" if it cannot
affect privileged tasks.

Note, this patch causes execve to fail when PR_SET_NO_NEW_PRIVS is
set and AppArmor is in use.  It is fixed in a subsequent patch.
Signed-off-by: NAndy Lutomirski <luto@amacapital.net>
Signed-off-by: NWill Drewry <wad@chromium.org>
Acked-by: NEric Paris <eparis@redhat.com>
Acked-by: NKees Cook <keescook@chromium.org>

v18: updated change desc
v17: using new define values as per 3.4
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

Fix failure in aa_change_onexec api when the request is made from a confined
task.  This failure was caused by two problems

 The AA_MAY_ONEXEC perm was not being mapped correctly for this case.

 The executable name was being checked as second time instead of using the
 requested onexec profile name, which may not be the same as the exec
 profile name. This mistake can not be exploited to grant extra permission
 because of the above flaw where the ONEXEC permission was not being mapped
 so it will not be granted.

BugLink: http://bugs.launchpad.net/bugs/963756Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>

Move the path name lookup failure messages into the main path name lookup
routine, as the information is useful in more than just aa_path_perm.

Also rename aa_get_name to aa_path_name as it is not getting a reference
counted object with a corresponding put fn.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NKees Cook <kees@ubuntu.com>

The pointer returned from tracehook_tracer_task() is only valid inside
the rcu_read_lock.  However the tracer pointer obtained is being passed
to aa_may_ptrace outside of the rcu_read_lock critical section.

Mover the aa_may_ptrace test into the rcu_read_lock critical section, to
fix this.

Kernels affected: 2.6.36 - 3.0
Reported-by: NOleg Nesterov <oleg@redhat.com>
Cc: stable@kernel.org
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>

tracehook.h is on the way out.  Rename tracehook_tracer_task() to
ptrace_parent() and move it from tracehook.h to ptrace.h.
Signed-off-by: NTejun Heo <tj@kernel.org>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: John Johansen <john.johansen@canonical.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NOleg Nesterov <oleg@redhat.com>

Fix build warnings for non-const use of get_task_cred.
Signed-off-by: NJames Morris <jmorris@namei.org>

AppArmor routines for controling domain transitions, which can occur at
exec or through self directed change_profile/change_hat calls.

Unconfined tasks are checked at exec against the profiles in the confining
profile namespace to determine if a profile should be attached to the task.

Confined tasks execs are controlled by the profile which provides rules
determining which execs are allowed and if so which profiles should be
transitioned to.

Self directed domain transitions allow a task to request transition
to a given profile.  If the transition is allowed then the profile will
be applied, either immeditately or at exec time depending on the request.
Immeditate self directed transitions have several security limitations
but have uses in setting up stub transition profiles and other limited
cases.
Signed-off-by: NJohn Johansen <john.johansen@canonical.com>
Signed-off-by: NJames Morris <jmorris@namei.org>