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=-12.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, 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 0C321C64E75 for ; Tue, 27 Oct 2020 16:06:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BA370208B8 for ; Tue, 27 Oct 2020 16:06:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603814799; bh=9iPo4/hp2YEw3swUk+14mrzdWhjCjXb3i5AxyrV/VZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=1WLxR5A9waLfpWsYsjesIs0zY+Rm83nqiIMJ34tdky7+fZNvvncO5iqZNPWDR3WSY vPydvqwIKo86wbkw6V57uKNE0e+aBg6Lp65bNcli+CBQULEOo3IE0YfvPsJwVoaqMX S2G4Dk29/pMY6KOAs3HGSvx33xTMcyWQGlkznkQY= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1806511AbgJ0QGL (ORCPT ); Tue, 27 Oct 2020 12:06:11 -0400 Received: from mail.kernel.org ([198.145.29.99]:52884 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1802783AbgJ0PvX (ORCPT ); Tue, 27 Oct 2020 11:51:23 -0400 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 1698A2225E; Tue, 27 Oct 2020 15:51:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1603813883; bh=9iPo4/hp2YEw3swUk+14mrzdWhjCjXb3i5AxyrV/VZA=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=Mi6o7c2afhDYR/hSfqEM0/4ZxO3S6BGhkRYwMct037p8KDeuJobFLDYikeYWu7R70 Xhq3DyCQ8UOverduO4VUdg77kz86f38cdyAP46MtrsE7BXSpmuGWkYv+P1dHcQW6WK W9DKlNXS5YI8ml7J+P+z8JlZ0PEtiPdQEeiBO2AA= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Thomas Tai , Konrad Rzeszutek Wilk , Christoph Hellwig , Sasha Levin Subject: [PATCH 5.9 702/757] dma-direct: Fix potential NULL pointer dereference Date: Tue, 27 Oct 2020 14:55:52 +0100 Message-Id: <20201027135523.426340054@linuxfoundation.org> X-Mailer: git-send-email 2.29.1 In-Reply-To: <20201027135450.497324313@linuxfoundation.org> References: <20201027135450.497324313@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Thomas Tai [ Upstream commit f959dcd6ddfd29235030e8026471ac1b022ad2b0 ] When booting the kernel v5.9-rc4 on a VM, the kernel would panic when printing a warning message in swiotlb_map(). The dev->dma_mask must not be a NULL pointer when calling the dma mapping layer. A NULL pointer check can potentially avoid the panic. Signed-off-by: Thomas Tai Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Christoph Hellwig Signed-off-by: Sasha Levin --- include/linux/dma-direct.h | 3 --- kernel/dma/mapping.c | 11 +++++++++++ 2 files changed, 11 insertions(+), 3 deletions(-) diff --git a/include/linux/dma-direct.h b/include/linux/dma-direct.h index 6e87225600ae3..064870844f06c 100644 --- a/include/linux/dma-direct.h +++ b/include/linux/dma-direct.h @@ -62,9 +62,6 @@ static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size, { dma_addr_t end = addr + size - 1; - if (!dev->dma_mask) - return false; - if (is_ram && !IS_ENABLED(CONFIG_ARCH_DMA_ADDR_T_64BIT) && min(addr, end) < phys_to_dma(dev, PFN_PHYS(min_low_pfn))) return false; diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 0d129421e75fc..7133d5c6e1a6d 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -144,6 +144,10 @@ dma_addr_t dma_map_page_attrs(struct device *dev, struct page *page, dma_addr_t addr; BUG_ON(!valid_dma_direction(dir)); + + if (WARN_ON_ONCE(!dev->dma_mask)) + return DMA_MAPPING_ERROR; + if (dma_map_direct(dev, ops)) addr = dma_direct_map_page(dev, page, offset, size, dir, attrs); else @@ -179,6 +183,10 @@ int dma_map_sg_attrs(struct device *dev, struct scatterlist *sg, int nents, int ents; BUG_ON(!valid_dma_direction(dir)); + + if (WARN_ON_ONCE(!dev->dma_mask)) + return 0; + if (dma_map_direct(dev, ops)) ents = dma_direct_map_sg(dev, sg, nents, dir, attrs); else @@ -213,6 +221,9 @@ dma_addr_t dma_map_resource(struct device *dev, phys_addr_t phys_addr, BUG_ON(!valid_dma_direction(dir)); + if (WARN_ON_ONCE(!dev->dma_mask)) + return DMA_MAPPING_ERROR; + /* Don't allow RAM to be mapped */ if (WARN_ON_ONCE(pfn_valid(PHYS_PFN(phys_addr)))) return DMA_MAPPING_ERROR; -- 2.25.1