From patchwork Tue Jan 8 20:50:43 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Logan Gunthorpe X-Patchwork-Id: 10752869 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 6088713BF for ; Tue, 8 Jan 2019 20:50:59 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 4B89028D65 for ; Tue, 8 Jan 2019 20:50:59 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 3FCDF28E7D; Tue, 8 Jan 2019 20:50:59 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E9CF328D65 for ; Tue, 8 Jan 2019 20:50:57 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729386AbfAHUu5 (ORCPT ); Tue, 8 Jan 2019 15:50:57 -0500 Received: from ale.deltatee.com ([207.54.116.67]:51906 "EHLO ale.deltatee.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728766AbfAHUu4 (ORCPT ); Tue, 8 Jan 2019 15:50:56 -0500 Received: from cgy1-donard.priv.deltatee.com ([172.16.1.31]) by ale.deltatee.com with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.89) (envelope-from ) id 1ggyKp-0004i8-Sa; Tue, 08 Jan 2019 13:50:53 -0700 Received: from gunthorp by cgy1-donard.priv.deltatee.com with local (Exim 4.89) (envelope-from ) id 1ggyKm-0000p5-Uj; Tue, 08 Jan 2019 13:50:48 -0700 From: Logan Gunthorpe To: linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Logan Gunthorpe , Intel SCU Linux support , Artur Paszkiewicz , "James E.J. Bottomley" , "Martin K. Petersen" , Christoph Hellwig , Jens Axboe , Jeff Moyer Date: Tue, 8 Jan 2019 13:50:43 -0700 Message-Id: <20190108205043.3122-1-logang@deltatee.com> X-Mailer: git-send-email 2.19.0 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 172.16.1.31 X-SA-Exim-Rcpt-To: linux-scsi@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, logang@deltatee.com, intel-linux-scu@intel.com, artur.paszkiewicz@intel.com, jejb@linux.ibm.com, martin.petersen@oracle.com, hch@lst.de, axboe@kernel.dk, jmoyer@redhat.com X-SA-Exim-Mail-From: gunthorp@deltatee.com Subject: [PATCH] scsi: isci: initialize shost fully before calling scsi_add_host() X-SA-Exim-Version: 4.2.1 (built Tue, 02 Aug 2016 21:08:31 +0000) X-SA-Exim-Scanned: Yes (on ale.deltatee.com) Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP scsi_mq_setup_tags(), which is called by scsi_add_host(), calculates the command size to allocate based on the prot_capabilities. In the isci driver, scsi_host_set_prot() is called after scsi_add_host() so the command size gets calculated to be smaller than it needs to be. Eventually, scsi_mq_init_request() locates the 'prot_sdb' after the command assuming it was sized correctly and a buffer overrun may occur. However, seeing blk_mq_alloc_rqs() rounds up to the nearest cache line size, the mistake can go unnoticed. The bug was noticed after the struct request size was reduced by commit 9d037ad707ed ("block: remove req->timeout_list") Which likely reduced the allocated space for the request by an entire cache line, enough that the overflow could be hit and it caused a panic, on boot, at: RIP: 0010:t10_pi_complete+0x77/0x1c0 Call Trace: sd_done+0xf5/0x340 scsi_finish_command+0xc3/0x120 blk_done_softirq+0x83/0xb0 __do_softirq+0xa1/0x2e6 irq_exit+0xbc/0xd0 call_function_single_interrupt+0xf/0x20 sd_done() would call scsi_prot_sg_count() which reads the number of entities in 'prot_sdb', but seeing 'prot_sdb' is located after the end of the allocated space it reads a garbage number and erroneously calls t10_pi_complete(). To prevent this, the calls to scsi_host_set_prot() are moved into isci_host_alloc() before the call to scsi_add_host(). Out of caution, also move the similar call to scsi_host_set_guard(). Fixes: 3d2d75254915 ("[SCSI] isci: T10 DIF support") Link: http://lkml.kernel.org/r/da851333-eadd-163a-8c78-e1f4ec5ec857@deltatee.com Signed-off-by: Logan Gunthorpe Cc: Intel SCU Linux support Cc: Artur Paszkiewicz Cc: "James E.J. Bottomley" Cc: "Martin K. Petersen" Cc: Christoph Hellwig Cc: Jens Axboe Cc: Jeff Moyer Reviewed-by: Jeff Moyer Reviewed-by: Jens Axboe --- drivers/scsi/isci/init.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/drivers/scsi/isci/init.c b/drivers/scsi/isci/init.c index 68b90c4f79a3..1727d0c71b12 100644 --- a/drivers/scsi/isci/init.c +++ b/drivers/scsi/isci/init.c @@ -576,6 +576,13 @@ static struct isci_host *isci_host_alloc(struct pci_dev *pdev, int id) shost->max_lun = ~0; shost->max_cmd_len = MAX_COMMAND_SIZE; + /* turn on DIF support */ + scsi_host_set_prot(shost, + SHOST_DIF_TYPE1_PROTECTION | + SHOST_DIF_TYPE2_PROTECTION | + SHOST_DIF_TYPE3_PROTECTION); + scsi_host_set_guard(shost, SHOST_DIX_GUARD_CRC); + err = scsi_add_host(shost, &pdev->dev); if (err) goto err_shost; @@ -663,13 +670,6 @@ static int isci_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) goto err_host_alloc; } pci_info->hosts[i] = h; - - /* turn on DIF support */ - scsi_host_set_prot(to_shost(h), - SHOST_DIF_TYPE1_PROTECTION | - SHOST_DIF_TYPE2_PROTECTION | - SHOST_DIF_TYPE3_PROTECTION); - scsi_host_set_guard(to_shost(h), SHOST_DIX_GUARD_CRC); } err = isci_setup_interrupts(pdev);