From patchwork Mon Jul 22 09:20:38 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Christoph Hellwig X-Patchwork-Id: 11051855 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 E72EF138D for ; Mon, 22 Jul 2019 09:20:54 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id C7C362624B for ; Mon, 22 Jul 2019 09:20:54 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id B4FD327861; Mon, 22 Jul 2019 09:20:54 +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=-7.7 required=2.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 37ED82624B for ; Mon, 22 Jul 2019 09:20:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728717AbfGVJUx (ORCPT ); Mon, 22 Jul 2019 05:20:53 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:50656 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727744AbfGVJUx (ORCPT ); Mon, 22 Jul 2019 05:20:53 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=Content-Transfer-Encoding: MIME-Version:Message-Id:Date:Subject:Cc:To:From:Sender:Reply-To:Content-Type: Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender: Resent-To:Resent-Cc:Resent-Message-ID:In-Reply-To:References:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=rozEWPkakpWOVwCBsdppdcawJNVVlIw+Eg8lASKNsgg=; b=tpkF1ayflIjh50YVCiIn61zsk 585NNt4GTav6znbiEh1nk7blBJDc4sIiGh980AUQln3qSyxICFWhCLRT0GbPYuDr6OYKmlMA+MYn4 YKX1UgcCicQwtRrLctNcdiEyYNDJWADTfK90HK3wQidBEL3ehgl2tjmh7J1mLtWu33buFKJDQLLG2 ctnqQimtuNqiaNzB7V5E0GCta+pc88Y6jjomsupaMd2evzlP002O4FNs9nH2xkE1q06lb00ItDuKT p7y4RNQw3rVvV+bJqbDefPnWuXcS5g8+A7gWxtwwYSCf75AexTWccRKIeIBdDmmnPn3KAvb+jyrGW XM4Jvxkpw==; Received: from 089144207240.atnat0016.highway.bob.at ([89.144.207.240] helo=localhost) by bombadil.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1hpUUs-0002Si-9l; Mon, 22 Jul 2019 09:20:42 +0000 From: Christoph Hellwig To: martin.petersen@oracle.com Cc: bvanassche@acm.org, tom.leiming@gmail.com, dexuan.linux@gmail.com, Damien.LeMoal@wdc.com, linux-scsi@vger.kernel.org Subject: [PATCH] scsi: fix the dma_max_mapping_size call Date: Mon, 22 Jul 2019 11:20:38 +0200 Message-Id: <20190722092038.17659-1-hch@lst.de> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-scsi-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-scsi@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP We should only call dma_max_mapping_size for devices that have a DMA mask set, otherwise we can run into a NULL pointer dereference that will crash the system. Also we need to do right shift to get the sectors from the size in bytes, not a left shift. Fixes: bdd17bdef7d8 ("scsi: core: take the DMA max mapping size into account") Reported-by: Bart Van Assche Reported-by: Ming Lei Signed-off-by: Christoph Hellwig Tested-by: Guilherme G. Piccoli --- drivers/scsi/scsi_lib.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index 9381171c2fc0..11e64b50497f 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -1784,8 +1784,10 @@ void __scsi_init_queue(struct Scsi_Host *shost, struct request_queue *q) blk_queue_max_integrity_segments(q, shost->sg_prot_tablesize); } - shost->max_sectors = min_t(unsigned int, shost->max_sectors, - dma_max_mapping_size(dev) << SECTOR_SHIFT); + if (dev->dma_mask) { + shost->max_sectors = min_t(unsigned int, shost->max_sectors, + dma_max_mapping_size(dev) >> SECTOR_SHIFT); + } blk_queue_max_hw_sectors(q, shost->max_sectors); if (shost->unchecked_isa_dma) blk_queue_bounce_limit(q, BLK_BOUNCE_ISA);