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,URIBL_BLOCKED,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 9CCF1C76186 for ; Mon, 29 Jul 2019 19:29:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 645CF2171F for ; Mon, 29 Jul 2019 19:29:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428565; bh=GFBXUdjCkqdWSyja6Renha4vSWYo1fMMNG5jLNDPuTA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=EtQzT70kV6IpzEN8UXfNR5h11RCtjzWWWq9iy9PMMSo+zoG0kj0s83FZCnQNoxfmQ i5xrycX9KoeX6mckDH1LAHcO/y2BAexgcU13Iq9uE5QomXegp+164v90zT489+qLVz 0fFYnMV8rXv0WyjNH4G8HwzH8vdu461LyWDmOkeg= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728374AbfG2T3Y (ORCPT ); Mon, 29 Jul 2019 15:29:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:42006 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727721AbfG2T3T (ORCPT ); Mon, 29 Jul 2019 15:29:19 -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 DAE30217D7; Mon, 29 Jul 2019 19:29:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1564428558; bh=GFBXUdjCkqdWSyja6Renha4vSWYo1fMMNG5jLNDPuTA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=iWDrhbig7bKmbb0yPMBKFlnYBVBEvvl76TkkSKmZqd+esdf96ikmq9/hAJFSMbIiy W1QzyNLLd/JFWyhn4ngKHz7EO0qnUV2u3uZbJzIBccqkCjKE4VU4eEct2803n5c1fT HLu36S2uajVhiSKVu0AovfP7TfMMoQPUOedoVnQ0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Christoph Hellwig , Hannes Reinecke , "Ewan D. Milne" , Ming Lei , "Martin K. Petersen" Subject: [PATCH 4.14 115/293] scsi: core: Fix race on creating sense cache Date: Mon, 29 Jul 2019 21:20:06 +0200 Message-Id: <20190729190833.421885040@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190729190820.321094988@linuxfoundation.org> References: <20190729190820.321094988@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: Ming Lei commit f9b0530fa02e0c73f31a49ef743e8f44eb8e32cc upstream. When scsi_init_sense_cache(host) is called concurrently from different hosts, each code path may find that no cache has been created and allocate a new one. The lack of locking can lead to potentially overriding a cache allocated by a different host. Fix the issue by moving 'mutex_lock(&scsi_sense_cache_mutex)' before scsi_select_sense_cache(). Fixes: 0a6ac4ee7c21 ("scsi: respect unchecked_isa_dma for blk-mq") Cc: Stable Cc: Christoph Hellwig Cc: Hannes Reinecke Cc: Ewan D. Milne Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/scsi_lib.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -71,11 +71,11 @@ int scsi_init_sense_cache(struct Scsi_Ho struct kmem_cache *cache; int ret = 0; + mutex_lock(&scsi_sense_cache_mutex); cache = scsi_select_sense_cache(shost->unchecked_isa_dma); if (cache) - return 0; + goto exit; - mutex_lock(&scsi_sense_cache_mutex); if (shost->unchecked_isa_dma) { scsi_sense_isadma_cache = kmem_cache_create("scsi_sense_cache(DMA)", @@ -90,7 +90,7 @@ int scsi_init_sense_cache(struct Scsi_Ho if (!scsi_sense_cache) ret = -ENOMEM; } - + exit: mutex_unlock(&scsi_sense_cache_mutex); return ret; }