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=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham 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 5AFB2C433E0 for ; Mon, 18 May 2020 17:39:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 327252086A for ; Mon, 18 May 2020 17:39:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823548; bh=QErEdJf4b4BcDiB3dkpFQ2FeNE88XMdpHbMw6WjjLfQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=VNS90rkL82P/4FhNbNU7FJmRODPYSO/CWPjkvHB8kuNHsKLgVF3A6SzBBtsztBKgV ij1fe2DJ0HHLjqzRHm708ldBd2hdF0SPKBDDCc6ev6cvZ6DCtdhKtRHIEU/itmzDQE vlsousL8nixz0qyOCUvLzEAQkOR8a2Lqg3fpjIzI= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728702AbgERRjH (ORCPT ); Mon, 18 May 2020 13:39:07 -0400 Received: from mail.kernel.org ([198.145.29.99]:33482 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728691AbgERRjF (ORCPT ); Mon, 18 May 2020 13:39:05 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 4CEA22086A; Mon, 18 May 2020 17:39:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1589823543; bh=QErEdJf4b4BcDiB3dkpFQ2FeNE88XMdpHbMw6WjjLfQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XD+kuVN2FwsIYv0xs8zx21gtvJ94tRY0D5mpE2kjMmFMwVrKArGxZbsfr7scYf4lx RkE3sBlUF5HgWnEVjuTtnDnMuuPP7eTMeTuL3iUbM1a2oMv4KnqmkH4m7yhmftm2Sg WZ1gZd/e3TyK44yb4ci3O0Amsuwa1XzCniyaFNw0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jens Axboe , Ben Hutchings Subject: [PATCH 4.4 25/86] blktrace: fix trace mutex deadlock Date: Mon, 18 May 2020 19:35:56 +0200 Message-Id: <20200518173455.557982692@linuxfoundation.org> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20200518173450.254571947@linuxfoundation.org> References: <20200518173450.254571947@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: Jens Axboe commit 2967acbb257a6a9bf912f4778b727e00972eac9b upstream. A previous commit changed the locking around registration/cleanup, but direct callers of blk_trace_remove() were missed. This means that if we hit the error path in setup, we will deadlock on attempting to re-acquire the queue trace mutex. Fixes: 1f2cac107c59 ("blktrace: fix unlocked access to init/start-stop/teardown") Signed-off-by: Jens Axboe Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- kernel/trace/blktrace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) --- a/kernel/trace/blktrace.c +++ b/kernel/trace/blktrace.c @@ -572,7 +572,7 @@ static int __blk_trace_setup(struct requ return ret; if (copy_to_user(arg, &buts, sizeof(buts))) { - blk_trace_remove(q); + __blk_trace_remove(q); return -EFAULT; } return 0; @@ -618,7 +618,7 @@ static int compat_blk_trace_setup(struct return ret; if (copy_to_user(arg, &buts.name, ARRAY_SIZE(buts.name))) { - blk_trace_remove(q); + __blk_trace_remove(q); return -EFAULT; }