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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,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 E0FFCC2D0DB for ; Fri, 24 Jan 2020 11:22:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id AE74321556 for ; Fri, 24 Jan 2020 11:22:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864942; bh=XYakaCXNYLllXDDo4tPnPA2c1J+mQYpUsBXO6Kz+Akw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=MSAsE8Fr61Vd6LcQgJhq1RUKEzBpCuE8iae3MiktCnhkujiVADIhmbMuz/g3AOArk kH3Tnrm62k8nYp30sZ7x9MPNS92PdagU7nQ+lAnz/fVGSfMuWrP7jwCuaHmFX6x7BL +iSKOqG3C+xnmq5KEbHxSCchXDSCtLQ4Xy2/dpZY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2391197AbgAXLWV (ORCPT ); Fri, 24 Jan 2020 06:22:21 -0500 Received: from mail.kernel.org ([198.145.29.99]:33534 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2390948AbgAXLWR (ORCPT ); Fri, 24 Jan 2020 06:22:17 -0500 Received: from localhost (ip-213-127-102-57.ip.prioritytelecom.net [213.127.102.57]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5869920704; Fri, 24 Jan 2020 11:22:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579864937; bh=XYakaCXNYLllXDDo4tPnPA2c1J+mQYpUsBXO6Kz+Akw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=JwOXAym81rZtT+YJMNtcpBap20Rqs8qYdo66Q9hAdQX/uEEJnBTRe6Gl3R7zhl/1y fNsd/dZSjf8ov5SeZlwUZP+4519qESJVV5M6fcEuHCHgAxub0bYHt98iktTb9B7evl 5+NHnXti7WvjLsNWT+W1JzGLKDB6BrTa0YZprNjU= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Namjae Jeon , Jeff Layton , Steve French , "Eric W. Biederman" , Sasha Levin Subject: [PATCH 4.19 399/639] signal/cifs: Fix cifs_put_tcp_session to call send_sig instead of force_sig Date: Fri, 24 Jan 2020 10:29:29 +0100 Message-Id: <20200124093136.910052750@linuxfoundation.org> X-Mailer: git-send-email 2.25.0 In-Reply-To: <20200124093047.008739095@linuxfoundation.org> References: <20200124093047.008739095@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 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 72abe3bcf0911d69b46c1e8bdb5612675e0ac42c ] 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: Namjae Jeon Cc: Jeff Layton Cc: Steve French Fixes: a5c3e1c725af ("Revert "cifs: No need to send SIGKILL to demux_thread during umount"") Fixes: e7ddee9037e7 ("cifs: disable sharing session and tcon and add new TCP sharing code") Signed-off-by: "Eric W. Biederman" Signed-off-by: Sasha Levin --- fs/cifs/connect.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c index 7e85070d010f4..a59dcda075343 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2454,7 +2454,7 @@ cifs_put_tcp_session(struct TCP_Server_Info *server, int from_reconnect) task = xchg(&server->tsk, NULL); if (task) - force_sig(SIGKILL, task); + send_sig(SIGKILL, task, 1); } static struct TCP_Server_Info * -- 2.20.1