tree dbae4aacbf3d4601e6f1dc9aa85d9e120dbdf652
parent 93feaa02a89b86546adcde75a017fdf36f2a988e
author Eric W. Biederman <ebiederm@xmission.com> 1535997766 +0200
committer Greg Kroah-Hartman <gregkh@linuxfoundation.org> 1542136613 -0800

signal: Always deliver the kernel's SIGKILL and SIGSTOP to a pid namespace init

[ Upstream commit 3597dfe01d12f570bc739da67f857fd222a3ea66 ]

Instead of playing whack-a-mole and changing SEND_SIG_PRIV to
SEND_SIG_FORCED throughout the kernel to ensure a pid namespace init
gets signals sent by the kernel, stop allowing a pid namespace init to
ignore SIGKILL or SIGSTOP sent by the kernel.  A pid namespace init is
only supposed to be able to ignore signals sent from itself and
children with SIG_DFL.

Fixes: 921cf9f63089 ("signals: protect cinit from unblocked SIG_DFL signals")
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>