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: Eric Paris <eparis@redhat.com>
Signed-off-by: Will Drewry <wad@chromium.org>
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: Andy Lutomirski <luto@amacapital.net>
v18: new acked-by, new description
Signed-off-by: James 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: Andy Lutomirski <luto@amacapital.net>
Signed-off-by: Will Drewry <wad@chromium.org>
Acked-by: Eric Paris <eparis@redhat.com>
Acked-by: Kees Cook <keescook@chromium.org>
v18: updated change desc
v17: using new define values as per 3.4
Signed-off-by: James 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/963756
Signed-off-by: John Johansen <john.johansen@canonical.com>
Signed-off-by: James 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: John Johansen <john.johansen@canonical.com>
Acked-by: Kees Cook <kees@ubuntu.com>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/security-testing-2.6: (54 commits)
tpm_nsc: Fix bug when loading multiple TPM drivers
tpm: Move tpm_tis_reenable_interrupts out of CONFIG_PNP block
tpm: Fix compilation warning when CONFIG_PNP is not defined
TOMOYO: Update kernel-doc.
tpm: Fix a typo
tpm_tis: Probing function for Intel iTPM bug
tpm_tis: Fix the probing for interrupts
tpm_tis: Delay ACPI S3 suspend while the TPM is busy
tpm_tis: Re-enable interrupts upon (S3) resume
tpm: Fix display of data in pubek sysfs entry
tpm_tis: Add timeouts sysfs entry
tpm: Adjust interface timeouts if they are too small
tpm: Use interface timeouts returned from the TPM
tpm_tis: Introduce durations sysfs entry
tpm: Adjust the durations if they are too small
tpm: Use durations returned from TPM
TOMOYO: Enable conditional ACL.
TOMOYO: Allow using argv[]/envp[] of execve() as conditions.
TOMOYO: Allow using executable's realpath and symlink's target as conditions.
TOMOYO: Allow using owner/group etc. of file objects as conditions.
...
Fix up trivial conflict in security/tomoyo/realpath.c
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: Oleg Nesterov <oleg@redhat.com>
Cc: stable@kernel.org
Signed-off-by: John 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: Tejun 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: Oleg Nesterov <oleg@redhat.com>
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: John Johansen <john.johansen@canonical.com>
Signed-off-by: James Morris <jmorris@namei.org>
