Re: [PATCH] usb,signal,security: only pass the cred, not the secid, to kill_pid_info_as_cred and security_task_kill

Greg KH
2017-09-09T05:40:25Z

On Fri, Sep 08, 2017 at 12:40:01PM -0400, Stephen Smalley wrote:
> commit d178bc3a708f39cbfefc3fab37032d3f2511b4ec ("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: Stephen Smalley <sds@tycho.nsa.gov>
> ---
> drivers/usb/core/devio.c | 10 ++--------
> include/linux/lsm_hooks.h | 5 +++--
> include/linux/sched/signal.h | 2 +-
> include/linux/security.h | 4 ++--
> kernel/signal.c | 6 +++---
> security/apparmor/lsm.c | 17 ++++++++++++-----
> security/security.c | 4 ++--
> security/selinux/hooks.c | 7 +++++--
> security/smack/smack_lsm.c | 12 +++++-------
> 9 files changed, 35 insertions(+), 32 deletions(-)

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>