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,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 C496DC432C0 for ; Wed, 27 Nov 2019 20:42:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 994CC21787 for ; Wed, 27 Nov 2019 20:42:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574887330; bh=XP4W78k7tWdh+OxHKfg/hOgoXSYlnsAKcT0blXHT8RY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=0ksWqFRqQK7NFPWRDUW4P82kwm5sMebzVLjgjgs63TqLbUupF7EeT7molUJjhmVTx ijcQmPMHw8tp6i9EKaDx11oldERZqC4ZAw7eBBhRQlTQGPnVIWuh2Xvwmb5WABlUTW zSc5wHE8N7n3FwPxpwK4d8ent92XAO5xR8lKiX3I= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727527AbfK0UmJ (ORCPT ); Wed, 27 Nov 2019 15:42:09 -0500 Received: from mail.kernel.org ([198.145.29.99]:48014 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729288AbfK0UmG (ORCPT ); Wed, 27 Nov 2019 15:42:06 -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 9DE5621787; Wed, 27 Nov 2019 20:42:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1574887326; bh=XP4W78k7tWdh+OxHKfg/hOgoXSYlnsAKcT0blXHT8RY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=LdkV5iJB4BgisIrrjnXjJ2nKUyZoxtaQxuz2+qkfUkBJRVeQ0bYPpkbFS32N3fBSg GMdMbWzaREvvyH9JD/CjeskVvsh8MYhjinPo5CK0uGSPUcDxYoMGdngbE2f/bEhal+ 37kCax0fTrAbwWh+FVPPbPLG+Ei5Me5wRuVo+Zxs= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Wenwen Wang , Sasha Levin Subject: [PATCH 4.9 025/151] misc: mic: fix a DMA pool free failure Date: Wed, 27 Nov 2019 21:30:08 +0100 Message-Id: <20191127203016.158952166@linuxfoundation.org> X-Mailer: git-send-email 2.24.0 In-Reply-To: <20191127203000.773542911@linuxfoundation.org> References: <20191127203000.773542911@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: Wenwen Wang [ Upstream commit 6b995f4eec34745f6cb20d66d5277611f0b3c3fa ] In _scif_prog_signal(), the boolean variable 'x100' is used to indicate whether the MIC Coprocessor is X100. If 'x100' is true, the status descriptor will be used to write the value to the destination. Otherwise, a DMA pool will be allocated for this purpose. Specifically, if the DMA pool is allocated successfully, two memory addresses will be returned. One is for the CPU and the other is for the device to access the DMA pool. The former is stored to the variable 'status' and the latter is stored to the variable 'src'. After the allocation, the address in 'src' is saved to 'status->src_dma_addr', which is actually in the DMA pool, and 'src' is then modified. Later on, if an error occurs, the execution flow will transfer to the label 'dma_fail', which will check 'x100' and free up the allocated DMA pool if 'x100' is false. The point here is that 'status->src_dma_addr' is used for freeing up the DMA pool. As mentioned before, 'status->src_dma_addr' is in the DMA pool. And thus, the device is able to modify this data. This can potentially cause failures when freeing up the DMA pool because of the modified device address. This patch avoids the above issue by using the variable 'src' (with necessary calculation) to free up the DMA pool. Signed-off-by: Wenwen Wang Signed-off-by: Greg Kroah-Hartman Signed-off-by: Sasha Levin --- drivers/misc/mic/scif/scif_fence.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/misc/mic/scif/scif_fence.c b/drivers/misc/mic/scif/scif_fence.c index cac3bcc308a7e..7bb929f05d852 100644 --- a/drivers/misc/mic/scif/scif_fence.c +++ b/drivers/misc/mic/scif/scif_fence.c @@ -272,7 +272,7 @@ static int _scif_prog_signal(scif_epd_t epd, dma_addr_t dst, u64 val) dma_fail: if (!x100) dma_pool_free(ep->remote_dev->signal_pool, status, - status->src_dma_addr); + src - offsetof(struct scif_status, val)); alloc_fail: return err; } -- 2.20.1