From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Sasha Levin To: stable@vger.kernel.org, linux-kernel@vger.kernel.org Cc: "Eric W. Biederman" , Sasha Levin Subject: [PATCH AUTOSEL 4.4 30/32] signal: Always deliver the kernel's SIGKILL and SIGSTOP to a pid namespace init Date: Wed, 31 Oct 2018 19:11:35 -0400 Message-Id: <20181031231137.29429-30-sashal@kernel.org> In-Reply-To: <20181031231137.29429-1-sashal@kernel.org> References: <20181031231137.29429-1-sashal@kernel.org> List-ID: From: "Eric W. Biederman" [ 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 Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- kernel/signal.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/signal.c b/kernel/signal.c index 8bfbc47f0a23..5b1313309356 100644 --- a/kernel/signal.c +++ b/kernel/signal.c @@ -991,7 +991,7 @@ static int __send_signal(int sig, struct siginfo *info, struct task_struct *t, result = TRACE_SIGNAL_IGNORED; if (!prepare_signal(sig, t, - from_ancestor_ns || (info == SEND_SIG_FORCED))) + from_ancestor_ns || (info == SEND_SIG_PRIV) || (info == SEND_SIG_FORCED))) goto ret; pending = group ? &t->signal->shared_pending : &t->pending; -- 2.17.1