From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0661EC7618F for ; Mon, 15 Jul 2019 14:53:27 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4DA42067C for ; Mon, 15 Jul 2019 14:53:26 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563202406; bh=drgLR4zB1/qQLoUjERC8AKlBaH9Az/5UxfkYH1IcjG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=V/2bze/1/9x3tIi1YZfzzUzXVW8Aoa4FyCuIDOxm+7s8RgwiVNgNzsJvf9W1UfFl/ umf3rnCF2jIbKDS1Q02IbaBQPs7CGC8mPiEUdGP5oHGIodHM4nD2j3ihjUDwJyh3nF R2yE9K/4ehZ6IDHpwaCyQuSXSrVSo6x/2PG7fg68= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733213AbfGOOxZ (ORCPT ); Mon, 15 Jul 2019 10:53:25 -0400 Received: from mail.kernel.org ([198.145.29.99]:41454 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731218AbfGOO3l (ORCPT ); Mon, 15 Jul 2019 10:29:41 -0400 Received: from sasha-vm.mshome.net (unknown [73.61.17.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 487CF20868; Mon, 15 Jul 2019 14:29:38 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1563200980; bh=drgLR4zB1/qQLoUjERC8AKlBaH9Az/5UxfkYH1IcjG4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Uj4PPTpPoFQs7ZL32dbMLrcTlUUOVKq4DnsVTrpia+j6cumH2q4DftrDriQOpKZDp lunMmtTAd0AXEuX/sgNcNra31IjzybyO2pfqdnZWFfC4r5GiqINiNNgRYaVbu98a18 MuJXWldXGge9KQGU1HE3r/b0fzUSC1pk33a4+JB4= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Eric W. Biederman" , Daniel Lezcano , Serge Hallyn , Oleg Nesterov , Sasha Levin Subject: [PATCH AUTOSEL 4.14 017/105] signal/pid_namespace: Fix reboot_pid_ns to use send_sig not force_sig Date: Mon, 15 Jul 2019 10:27:11 -0400 Message-Id: <20190715142839.9896-17-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190715142839.9896-1-sashal@kernel.org> References: <20190715142839.9896-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: "Eric W. Biederman" [ Upstream commit f9070dc94542093fd516ae4ccea17ef46a4362c5 ] The locking in force_sig_info is not prepared to deal with a task that exits or execs (as sighand may change). The is not a locking problem in force_sig as force_sig is only built to handle synchronous exceptions. Further the function force_sig_info changes the signal state if the signal is ignored, or blocked or if SIGNAL_UNKILLABLE will prevent the delivery of the signal. The signal SIGKILL can not be ignored and can not be blocked and SIGNAL_UNKILLABLE won't prevent it from being delivered. So using force_sig rather than send_sig for SIGKILL is confusing and pointless. Because it won't impact the sending of the signal and and because using force_sig is wrong, replace force_sig with send_sig. Cc: Daniel Lezcano Cc: Serge Hallyn Cc: Oleg Nesterov Fixes: cf3f89214ef6 ("pidns: add reboot_pid_ns() to handle the reboot syscall") Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- kernel/pid_namespace.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/pid_namespace.c b/kernel/pid_namespace.c index 4918314893bc..22091c88b3bb 100644 --- a/kernel/pid_namespace.c +++ b/kernel/pid_namespace.c @@ -351,7 +351,7 @@ int reboot_pid_ns(struct pid_namespace *pid_ns, int cmd) } read_lock(&tasklist_lock); - force_sig(SIGKILL, pid_ns->child_reaper); + send_sig(SIGKILL, pid_ns->child_reaper, 1); read_unlock(&tasklist_lock); do_exit(0); -- 2.20.1