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=-9.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,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 82B16C432C0 for ; Tue, 19 Nov 2019 05:35:35 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 55F57206EC for ; Tue, 19 Nov 2019 05:35:35 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574141735; bh=jXkiVzZYSLUq0yhlysGpFlmVqSm2aSwxQEawDZL8+xY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=HUJLAThppHwGcX5nphuJemiJPEGdv+ncnHxCqMWGJKCwMnd+pFL5TqPdpaD7tNf5o v3TLmAhG2dLhqbPsnNsxKrRnonvgSUW7mk6IpGnEl91aL9RHHowXH7zrBuBXXqhuYM jsjarUKNrhmGSYo978SeV3RobMIrVwam70miN8es= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728110AbfKSFfe (ORCPT ); Tue, 19 Nov 2019 00:35:34 -0500 Received: from mail.kernel.org ([198.145.29.99]:56454 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729817AbfKSFfa (ORCPT ); Tue, 19 Nov 2019 00:35:30 -0500 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 D095B20862; Tue, 19 Nov 2019 05:35:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574141730; bh=jXkiVzZYSLUq0yhlysGpFlmVqSm2aSwxQEawDZL8+xY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=g8oWlJfevFGkyuuQOvCt3m2ptRut+0ojU3TgsjnFt8IVMcsUMHL6yIB3eImi190Uk bpSlZMOn71yyEYAIovCVy+SQ5tsx3C7aB+++/aRkewe8gba8vDcfVZ3vrekvhl/UaM L6MjJO6DE8f5SyJvEa/7h853drMLV8O9o9W550m4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Breno Leitao , Michael Ellerman , Sasha Levin Subject: [PATCH 4.19 260/422] powerpc/iommu: Avoid derefence before pointer check Date: Tue, 19 Nov 2019 06:17:37 +0100 Message-Id: <20191119051415.839491019@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191119051400.261610025@linuxfoundation.org> References: <20191119051400.261610025@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: Breno Leitao [ Upstream commit 984ecdd68de0fa1f63ce205d6c19ef5a7bc67b40 ] The tbl pointer is being derefenced by IOMMU_PAGE_SIZE prior the check if it is not NULL. Just moving the dereference code to after the check, where there will be guarantee that 'tbl' will not be NULL. Signed-off-by: Breno Leitao Signed-off-by: Michael Ellerman Signed-off-by: Sasha Levin --- arch/powerpc/kernel/iommu.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/powerpc/kernel/iommu.c b/arch/powerpc/kernel/iommu.c index 19b4c628f3bec..f0dc680e659af 100644 --- a/arch/powerpc/kernel/iommu.c +++ b/arch/powerpc/kernel/iommu.c @@ -785,9 +785,9 @@ dma_addr_t iommu_map_page(struct device *dev, struct iommu_table *tbl, vaddr = page_address(page) + offset; uaddr = (unsigned long)vaddr; - npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl)); if (tbl) { + npages = iommu_num_pages(uaddr, size, IOMMU_PAGE_SIZE(tbl)); align = 0; if (tbl->it_page_shift < PAGE_SHIFT && size >= PAGE_SIZE && ((unsigned long)vaddr & ~PAGE_MASK) == 0) -- 2.20.1