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 0D7FCC33CB6 for ; Thu, 16 Jan 2020 18:07:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D52622073A for ; Thu, 16 Jan 2020 18:07:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579198026; bh=9mwGrx6aEgxNRi/HJ+0HH6YChaUmnqQW3NP2bo8ezdU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=K1Z1r6ypCy5twClNsIrOAwkir7YnRCubLpc2pI6KXHBSdDIuV1EQ2oU863j9a9A+k jXJgMMrnWsAVcAZ7nLf2J/VwJqBKWjxIr/ctAiX169ToOUfOvgskQOz5Ps/fsb3v7Z BI37ATFyNkCW9cfnGtEfHJKK+lu73d4r40FqypMw= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731630AbgAPRjT (ORCPT ); Thu, 16 Jan 2020 12:39:19 -0500 Received: from mail.kernel.org ([198.145.29.99]:55522 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2393455AbgAPRjS (ORCPT ); Thu, 16 Jan 2020 12:39:18 -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 7FCF8246D3; Thu, 16 Jan 2020 17:39:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1579196357; bh=9mwGrx6aEgxNRi/HJ+0HH6YChaUmnqQW3NP2bo8ezdU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=NTPUtDN3ntsnHm0vAwQCMFCH1duUlvPBF/lvgp5LnrbPzr98dKb8yWWLhkktl04Xn uKb0QYhc06M9UGpQU/syMyUWyfaR+HOhC6zkDins2psvMo3wNfBgkjQUlJjBCzOhjy 0JcUmnf8LbfS6oXlma3ZuJb7TWoesEyNql1Cyvnw= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: "Eric W. Biederman" , Namjae Jeon , Jeff Layton , Steve French , Sasha Levin , linux-cifs@vger.kernel.org, samba-technical@lists.samba.org Subject: [PATCH AUTOSEL 4.9 149/251] signal/cifs: Fix cifs_put_tcp_session to call send_sig instead of force_sig Date: Thu, 16 Jan 2020 12:34:58 -0500 Message-Id: <20200116173641.22137-109-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20200116173641.22137-1-sashal@kernel.org> References: <20200116173641.22137-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-cifs-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-cifs@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 e43ba6db2bdd..110febd69737 100644 --- a/fs/cifs/connect.c +++ b/fs/cifs/connect.c @@ -2221,7 +2221,7 @@ 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