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  1. 15 5月, 2017 1 次提交
    • M
      LSM: Enable multiple calls to security_add_hooks() for the same LSM · 3bb857e4
      由 Mickaël Salaün 提交于 
      The commit d69dece5 ("LSM: Add /sys/kernel/security/lsm") extend
security_add_hooks() with a new parameter to register the LSM name,
which may be useful to make the list of currently loaded LSM available
to userspace. However, there is no clean way for an LSM to split its
hook declarations into multiple files, which may reduce the mess with
all the included files (needed for LSM hook argument types) and make the
source code easier to review and maintain.

This change allows an LSM to register multiple times its hook while
keeping a consistent list of LSM names as described in
Documentation/security/LSM.txt . The list reflects the order in which
checks are made. This patch only check for the last registered LSM. If
an LSM register multiple times its hooks, interleaved with other LSM
registrations (which should not happen), its name will still appear in
the same order that the hooks are called, hence multiple times.

To sum up, "capability,selinux,foo,foo" will be replaced with
"capability,selinux,foo", however "capability,foo,selinux,foo" will
remain as is.
Signed-off-by: NMickaël Salaün <mic@digikod.net>
Acked-by: NKees Cook <keescook@chromium.org>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>
      3bb857e4
  3. 28 3月, 2017 1 次提交
    • T
      LSM: Revive security_task_alloc() hook and per "struct task_struct" security blob. · e4e55b47
      由 Tetsuo Handa 提交于 
      We switched from "struct task_struct"->security to "struct cred"->security
in Linux 2.6.29. But not all LSM modules were happy with that change.
TOMOYO LSM module is an example which want to use per "struct task_struct"
security blob, for TOMOYO's security context is defined based on "struct
task_struct" rather than "struct cred". AppArmor LSM module is another
example which want to use it, for AppArmor is currently abusing the cred
a little bit to store the change_hat and setexeccon info. Although
security_task_free() hook was revived in Linux 3.4 because Yama LSM module
wanted to release per "struct task_struct" security blob,
security_task_alloc() hook and "struct task_struct"->security field were
not revived. Nowadays, we are getting proposals of lightweight LSM modules
which want to use per "struct task_struct" security blob.

We are already allowing multiple concurrent LSM modules (up to one fully
armored module which uses "struct cred"->security field or exclusive hooks
like security_xfrm_state_pol_flow_match(), plus unlimited number of
lightweight modules which do not use "struct cred"->security nor exclusive
hooks) as long as they are built into the kernel. But this patch does not
implement variable length "struct task_struct"->security field which will
become needed when multiple LSM modules want to use "struct task_struct"->
security field. Although it won't be difficult to implement variable length
"struct task_struct"->security field, let's think about it after we merged
this patch.
Signed-off-by: NTetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Acked-by: NJohn Johansen <john.johansen@canonical.com>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Acked-by: NCasey Schaufler <casey@schaufler-ca.com>
Tested-by: NDjalal Harouni <tixxdz@gmail.com>
Acked-by: NJosé Bollo <jobol@nonadev.net>
Cc: Paul Moore <paul@paul-moore.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Eric Paris <eparis@parisplace.org>
Cc: Kees Cook <keescook@chromium.org>
Cc: James Morris <james.l.morris@oracle.com>
Cc: José Bollo <jobol@nonadev.net>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>
      e4e55b47
  5. 24 3月, 2017 1 次提交
  7. 06 3月, 2017 2 次提交
    • J
      security: mark LSM hooks as __ro_after_init · ca97d939
      由 James Morris 提交于 
      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>
      ca97d939
    • S
      prlimit,security,selinux: add a security hook for prlimit · 791ec491
      由 Stephen Smalley 提交于 
      When SELinux was first added to the kernel, a process could only get
and set its own resource limits via getrlimit(2) and setrlimit(2), so no
MAC checks were required for those operations, and thus no security hooks
were defined for them. Later, SELinux introduced a hook for setlimit(2)
with a check if the hard limit was being changed in order to be able to
rely on the hard limit value as a safe reset point upon context
transitions.

Later on, when prlimit(2) was added to the kernel with the ability to get
or set resource limits (hard or soft) of another process, LSM/SELinux was
not updated other than to pass the target process to the setrlimit hook.
This resulted in incomplete control over both getting and setting the
resource limits of another process.

Add a new security_task_prlimit() hook to the check_prlimit_permission()
function to provide complete mediation.  The hook is only called when
acting on another task, and only if the existing DAC/capability checks
would allow access.  Pass flags down to the hook to indicate whether the
prlimit(2) call will read, write, or both read and write the resource
limits of the target process.

The existing security_task_setrlimit() hook is left alone; it continues
to serve a purpose in supporting the ability to make decisions based on
the old and/or new resource limit values when setting limits.  This
is consistent with the DAC/capability logic, where
check_prlimit_permission() performs generic DAC/capability checks for
acting on another task, while do_prlimit() performs a capability check
based on a comparison of the old and new resource limits.  Fix the
inline documentation for the hook to match the code.

Implement the new hook for SELinux.  For setting resource limits, we
reuse the existing setrlimit permission.  Note that this does overload
the setrlimit permission to mean the ability to set the resource limit
(soft or hard) of another process or the ability to change one's own
hard limit.  For getting resource limits, a new getrlimit permission
is defined.  This was not originally defined since getrlimit(2) could
only be used to obtain a process' own limits.
Signed-off-by: NStephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>
      791ec491
  9. 19 1月, 2017 1 次提交
  11. 13 1月, 2017 1 次提交
  13. 09 1月, 2017 1 次提交
  15. 09 8月, 2016 3 次提交
  17. 21 7月, 2016 1 次提交
  19. 06 6月, 2016 1 次提交
    • C
      LSM: Fix for security_inode_getsecurity and -EOPNOTSUPP · 2885c1e3
      由 Casey Schaufler 提交于 
      Serge Hallyn pointed out that the current implementation of
security_inode_getsecurity() works if there is only one hook
provided for it, but will fail if there is more than one and
the attribute requested isn't supplied by the first module.
This isn't a problem today, since only SELinux and Smack
provide this hook and there is (currently) no way to enable
both of those modules at the same time. Serge, however, wants
to introduce a capability attribute and an inode_getsecurity
hook in the capability security module to handle it. This
addresses that upcoming problem, will be required for "extreme
stacking" and is just a better implementation.
Signed-off-by: NCasey Schaufler <casey@schaufler-ca.com>
Acked-by: NSerge Hallyn <serge@hallyn.com>
Signed-off-by: NJames Morris <james.l.morris@oracle.com>
      2885c1e3
  21. 23 4月, 2016 1 次提交
    • B
      security: Introduce security_settime64() · 457db29b
      由 Baolin Wang 提交于 
      security_settime() uses a timespec, which is not year 2038 safe
on 32bit systems. Thus this patch introduces the security_settime64()
function with timespec64 type. We also convert the cap_settime() helper
function to use the 64bit types.

This patch then moves security_settime() to the header file as an
inline helper function so that existing users can be iteratively
converted.

None of the existing hooks is using the timespec argument and therefor
the patch is not making any functional changes.

Cc: Serge Hallyn <serge.hallyn@canonical.com>,
Cc: James Morris <james.l.morris@oracle.com>,
Cc: "Serge E. Hallyn" <serge@hallyn.com>,
Cc: Paul Moore <pmoore@redhat.com>
Cc: Stephen Smalley <sds@tycho.nsa.gov>
Cc: Kees Cook <keescook@chromium.org>
Cc: Prarit Bhargava <prarit@redhat.com>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Ingo Molnar <mingo@kernel.org>
Reviewed-by: NJames Morris <james.l.morris@oracle.com>
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
[jstultz: Reworded commit message]
Signed-off-by: NJohn Stultz <john.stultz@linaro.org>
      457db29b
  23. 21 4月, 2016 1 次提交
  25. 11 4月, 2016 1 次提交
  27. 28 3月, 2016 9 次提交
  29. 21 2月, 2016 4 次提交
  31. 19 2月, 2016 2 次提交
  33. 25 12月, 2015 3 次提交
  35. 26 8月, 2015 1 次提交
  37. 28 7月, 2015 1 次提交
  39. 10 7月, 2015 1 次提交
    • E
      vfs: Commit to never having exectuables on proc and sysfs. · 90f8572b
      由 Eric W. Biederman 提交于 
      Today proc and sysfs do not contain any executable files.  Several
applications today mount proc or sysfs without noexec and nosuid and
then depend on there being no exectuables files on proc or sysfs.
Having any executable files show on proc or sysfs would cause
a user space visible regression, and most likely security problems.

Therefore commit to never allowing executables on proc and sysfs by
adding a new flag to mark them as filesystems without executables and
enforce that flag.

Test the flag where MNT_NOEXEC is tested today, so that the only user
visible effect will be that exectuables will be treated as if the
execute bit is cleared.

The filesystems proc and sysfs do not currently incoporate any
executable files so this does not result in any user visible effects.

This makes it unnecessary to vet changes to proc and sysfs tightly for
adding exectuable files or changes to chattr that would modify
existing files, as no matter what the individual file say they will
not be treated as exectuable files by the vfs.

Not having to vet changes to closely is important as without this we
are only one proc_create call (or another goof up in the
implementation of notify_change) from having problematic executables
on proc.  Those mistakes are all too easy to make and would create
a situation where there are security issues or the assumptions of
some program having to be broken (and cause userspace regressions).
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>
      90f8572b
  41. 12 5月, 2015 3 次提交