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,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 8ED6EC33CAF for ; Thu, 16 Jan 2020 18:54:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6857C206D7 for ; Thu, 16 Jan 2020 18:54:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579200861; bh=y/nZ42/FMMXceNUw7WAIY9pg7MUgfngQZU/ejKKMVf0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MXqjIh7Qz6MxGg48i79x2607/K93BpdXJnSvpPq5jLspMpzJsAm0FVxQT8JoZDMSo 2OGscX+LbLu21Xz+7g3OMdYozM6CTroWPaqHAp3hUbGZ1oewh812T+osX8gOd5N7CI /2zAMWjTOtZJz1zT/eno8U5s0dO0TPW36cJe16qs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389278AbgAPSyN (ORCPT ); Thu, 16 Jan 2020 13:54:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:41004 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389264AbgAPRIC (ORCPT ); Thu, 16 Jan 2020 12:08:02 -0500 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (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 8071B205F4; Thu, 16 Jan 2020 17:08:00 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579194481; bh=y/nZ42/FMMXceNUw7WAIY9pg7MUgfngQZU/ejKKMVf0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lxkRJdz/Jg0ZVpe+LoRAy28Ehf5LtnGp+nCQ2F3hsLJeeeIH+HEY5Y0zzIG+GhiIM HahhqQt/ycuNTwkS31ps1paXfX5sfkAOcsEe+g032PgfZimBx6DpfN/P8iVEQjpv9e BFhYnGhGyRk/M91POHi9lkPbc8jw7RakF6FLAORg= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Eric W. Biederman" , Alexei Starovoitov , "David S . Miller" , Sasha Levin , netdev@vger.kernel.org, bpf@vger.kernel.org Subject: [PATCH AUTOSEL 4.19 383/671] signal/bpfilter: Fix bpfilter_kernl to use send_sig not force_sig Date: Thu, 16 Jan 2020 12:00:21 -0500 Message-Id: <20200116170509.12787-120-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116170509.12787-1-sashal@kernel.org> References: <20200116170509.12787-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: bpf-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org From: "Eric W. Biederman" [ Upstream commit 1dfd1711de2952fd1bfeea7152bd1687a4eea771 ] The locking in force_sig_info is not prepared to deal with a task that exits or execs (as sighand may change). 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 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: Alexei Starovoitov Cc: David S. Miller Fixes: d2ba09c17a06 ("net: add skeleton of bpfilter kernel module") Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- net/bpfilter/bpfilter_kern.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/bpfilter/bpfilter_kern.c b/net/bpfilter/bpfilter_kern.c index 94e88f510c5b..450b257afa84 100644 --- a/net/bpfilter/bpfilter_kern.c +++ b/net/bpfilter/bpfilter_kern.c @@ -25,7 +25,7 @@ static void shutdown_umh(struct umh_info *info) return; tsk = get_pid_task(find_vpid(info->pid), PIDTYPE_PID); if (tsk) { - force_sig(SIGKILL, tsk); + send_sig(SIGKILL, tsk, 1); put_task_struct(tsk); } fput(info->pipe_to_umh); -- 2.20.1