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=-3.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS autolearn=no 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 B475CC432C0 for ; Wed, 20 Nov 2019 15:45:31 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 86AC820709 for ; Wed, 20 Nov 2019 15:45:31 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731173AbfKTPp3 (ORCPT ); Wed, 20 Nov 2019 10:45:29 -0500 Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:52598 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729722AbfKTPkQ (ORCPT ); Wed, 20 Nov 2019 10:40:16 -0500 Received: from [167.98.27.226] (helo=deadeye) by shadbolt.decadent.org.uk with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1iXS5U-0004ay-D1; Wed, 20 Nov 2019 15:40:12 +0000 Received: from ben by deadeye with local (Exim 4.93-RC1) (envelope-from ) id 1iXS5T-0004HW-Gn; Wed, 20 Nov 2019 15:40:11 +0000 Content-Type: text/plain; charset="UTF-8" Content-Disposition: inline Content-Transfer-Encoding: 8bit MIME-Version: 1.0 From: Ben Hutchings To: linux-kernel@vger.kernel.org, stable@vger.kernel.org CC: akpm@linux-foundation.org, Denis Kirjanov , "Steve French" , "Ronnie Sahlberg" , "Pavel Shilovsky" Date: Wed, 20 Nov 2019 15:37:36 +0000 Message-ID: X-Mailer: LinuxStableQueue (scripts by bwh) X-Patchwork-Hint: ignore Subject: [PATCH 3.16 26/83] SMB3: Fix deadlock in validate negotiate hits reconnect In-Reply-To: X-SA-Exim-Connect-IP: 167.98.27.226 X-SA-Exim-Mail-From: ben@decadent.org.uk X-SA-Exim-Scanned: No (on shadbolt.decadent.org.uk); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.16.78-rc1 review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Shilovsky commit e99c63e4d86d3a94818693147b469fa70de6f945 upstream. Currently we skip SMB2_TREE_CONNECT command when checking during reconnect because Tree Connect happens when establishing an SMB session. For SMB 3.0 protocol version the code also calls validate negotiate which results in SMB2_IOCL command being sent over the wire. This may deadlock on trying to acquire a mutex when checking for reconnect. Fix this by skipping SMB2_IOCL command when doing the reconnect check. Signed-off-by: Pavel Shilovsky Signed-off-by: Steve French Reviewed-by: Ronnie Sahlberg Signed-off-by: Ben Hutchings --- fs/cifs/smb2pdu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/cifs/smb2pdu.c +++ b/fs/cifs/smb2pdu.c @@ -171,7 +171,7 @@ smb2_reconnect(__le16 smb2_command, stru if (tcon == NULL) return 0; - if (smb2_command == SMB2_TREE_CONNECT) + if (smb2_command == SMB2_TREE_CONNECT || smb2_command == SMB2_IOCTL) return 0; if (tcon->tidStatus == CifsExiting) {