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=-7.0 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=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 4CEA1C5B57D for ; Tue, 2 Jul 2019 08:03:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 21A7E2184B for ; Tue, 2 Jul 2019 08:03:11 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562054591; bh=JZqU6SbEu1G9od63bFj+X/LVOZySTd08frXzcfvf4FI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=xNxxREgXHwIRXnxVXkK1C+EXq/KH2OEsnF4MjjfyskXRz//MByP3dhfWBO1oGOJZm h/7rpZh25RJIRh2C7fYTq9uP3Kb2vxTHjdHcdnt33cgKtJnsV/mzgNk31mtL8IKNfn Y/HlWZOcGee4HbAVNp3FaaDyXBC3KXBu74+XOoDM= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727348AbfGBIDJ (ORCPT ); Tue, 2 Jul 2019 04:03:09 -0400 Received: from mail.kernel.org ([198.145.29.99]:47936 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727312AbfGBIDH (ORCPT ); Tue, 2 Jul 2019 04:03:07 -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 4BCDD2064A; Tue, 2 Jul 2019 08:03:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1562054586; bh=JZqU6SbEu1G9od63bFj+X/LVOZySTd08frXzcfvf4FI=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=PxJXbBWy37Rgj2/UBoH8mw0qTReEJzf0XZOQUN7lcVi02bYAb5eUxZsLRrCjAt7nc nwrL68gK/OTMs1+XECm4F4rP+It7F0dpFGHRr5+d0Dl7rlAMxUVIELJsNIxGVulC9m AHzBu11o79JT62M688D9Bbn//xhnF7iFzgJcR88g= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jan Kara , "Ewan D. Milne" , "Martin K. Petersen" Subject: [PATCH 5.1 20/55] scsi: vmw_pscsi: Fix use-after-free in pvscsi_queue_lck() Date: Tue, 2 Jul 2019 10:01:28 +0200 Message-Id: <20190702080125.094595624@linuxfoundation.org> X-Mailer: git-send-email 2.22.0 In-Reply-To: <20190702080124.103022729@linuxfoundation.org> References: <20190702080124.103022729@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: Jan Kara commit 240b4cc8fd5db138b675297d4226ec46594d9b3b upstream. Once we unlock adapter->hw_lock in pvscsi_queue_lck() nothing prevents just queued scsi_cmnd from completing and freeing the request. Thus cmd->cmnd[0] dereference can dereference already freed request leading to kernel crashes or other issues (which one of our customers observed). Store cmd->cmnd[0] in a local variable before unlocking adapter->hw_lock to fix the issue. CC: Signed-off-by: Jan Kara Reviewed-by: Ewan D. Milne Signed-off-by: Martin K. Petersen Signed-off-by: Greg Kroah-Hartman --- drivers/scsi/vmw_pvscsi.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) --- a/drivers/scsi/vmw_pvscsi.c +++ b/drivers/scsi/vmw_pvscsi.c @@ -763,6 +763,7 @@ static int pvscsi_queue_lck(struct scsi_ struct pvscsi_adapter *adapter = shost_priv(host); struct pvscsi_ctx *ctx; unsigned long flags; + unsigned char op; spin_lock_irqsave(&adapter->hw_lock, flags); @@ -775,13 +776,14 @@ static int pvscsi_queue_lck(struct scsi_ } cmd->scsi_done = done; + op = cmd->cmnd[0]; dev_dbg(&cmd->device->sdev_gendev, - "queued cmd %p, ctx %p, op=%x\n", cmd, ctx, cmd->cmnd[0]); + "queued cmd %p, ctx %p, op=%x\n", cmd, ctx, op); spin_unlock_irqrestore(&adapter->hw_lock, flags); - pvscsi_kick_io(adapter, cmd->cmnd[0]); + pvscsi_kick_io(adapter, op); return 0; }