From patchwork Tue Jan 7 20:54:27 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg KH X-Patchwork-Id: 234311 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=-6.8 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,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 2CE1EC282DD for ; Tue, 7 Jan 2020 21:17:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E3D512087F for ; Tue, 7 Jan 2020 21:17:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578431842; bh=Puf4cjTzQ89dCmtslBrHrCifQTnzFDr6sMafzpFF7P8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=eesmumW/RA6cRHBJtmKPiC2vBsdzE3xO5OWVMgB2vylGgWr7Zf5xqgqdZKauni6oS omIKi9SoYoAf3u4cPRfBiiU0HV4QQMF3IB/Lmgvyx3ekPQbsOfdkLy6Qx5kZ+E5iep NwDVLbmhEs4ei7oUKPNjA1Gx9RXxTERpu9FaS8cA= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729312AbgAGVF4 (ORCPT ); Tue, 7 Jan 2020 16:05:56 -0500 Received: from mail.kernel.org ([198.145.29.99]:53674 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729309AbgAGVFz (ORCPT ); Tue, 7 Jan 2020 16:05:55 -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 E41BE2077B; Tue, 7 Jan 2020 21:05:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1578431155; bh=Puf4cjTzQ89dCmtslBrHrCifQTnzFDr6sMafzpFF7P8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nZd3lR51T6wc3Sbvs6xRia3qH3fbsWD2UHIYNuMVK+wXK7M7aSY2aLvd+LITHox/q f3HODi7WwmHT1U5f02md7t4iBEMIU6mBgF9tMaadGCVhOsalUdu/898NYyIMflfY1t Hdrraba9skC72a2EAv3EVgRn7NGrbMYCHXn2cQeQ= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, kbuild test robot , Lukas Wunner , Vinod Koul Subject: [PATCH 4.19 057/115] dmaengine: Fix access to uninitialized dma_slave_caps Date: Tue, 7 Jan 2020 21:54:27 +0100 Message-Id: <20200107205302.962415588@linuxfoundation.org> X-Mailer: git-send-email 2.24.1 In-Reply-To: <20200107205240.283674026@linuxfoundation.org> References: <20200107205240.283674026@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Lukas Wunner commit 53a256a9b925b47c7e67fc1f16ca41561a7b877c upstream. dmaengine_desc_set_reuse() allocates a struct dma_slave_caps on the stack, populates it using dma_get_slave_caps() and then accesses one of its members. However dma_get_slave_caps() may fail and this isn't accounted for, leading to a legitimate warning of gcc-4.9 (but not newer versions): In file included from drivers/spi/spi-bcm2835.c:19:0: drivers/spi/spi-bcm2835.c: In function 'dmaengine_desc_set_reuse': >> include/linux/dmaengine.h:1370:10: warning: 'caps.descriptor_reuse' is used uninitialized in this function [-Wuninitialized] if (caps.descriptor_reuse) { Fix it, thereby also silencing the gcc-4.9 warning. The issue has been present for 4 years but surfaces only now that the first caller of dmaengine_desc_set_reuse() has been added in spi-bcm2835.c. Another user of reusable DMA descriptors has existed for a while in pxa_camera.c, but it sets the DMA_CTRL_REUSE flag directly instead of calling dmaengine_desc_set_reuse(). Nevertheless, tag this commit for stable in case there are out-of-tree users. Fixes: 272420214d26 ("dmaengine: Add DMA_CTRL_REUSE") Reported-by: kbuild test robot Signed-off-by: Lukas Wunner Cc: stable@vger.kernel.org # v4.3+ Link: https://lore.kernel.org/r/ca92998ccc054b4f2bfd60ef3adbab2913171eac.1575546234.git.lukas@wunner.de Signed-off-by: Vinod Koul Signed-off-by: Greg Kroah-Hartman --- include/linux/dmaengine.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) --- a/include/linux/dmaengine.h +++ b/include/linux/dmaengine.h @@ -1373,8 +1373,11 @@ static inline int dma_get_slave_caps(str static inline int dmaengine_desc_set_reuse(struct dma_async_tx_descriptor *tx) { struct dma_slave_caps caps; + int ret; - dma_get_slave_caps(tx->chan, &caps); + ret = dma_get_slave_caps(tx->chan, &caps); + if (ret) + return ret; if (caps.descriptor_reuse) { tx->flags |= DMA_CTRL_REUSE;