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=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,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 CF432C432C3 for ; Sat, 16 Nov 2019 16:14:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 9E54021479 for ; Sat, 16 Nov 2019 16:14:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573920859; bh=XP4W78k7tWdh+OxHKfg/hOgoXSYlnsAKcT0blXHT8RY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=mvojtpPvfJY3LUaR9vJ4ohlKSncV369fX91WoGbAgS/i8ZSFlbzIvs8fCYbTzXuut 7ZhpmZWIRmCvyuNvpnieQvTbfsVa10xz1E2N7PtXSL7QsBEGz6g6BrhaZWZhbmyO0u ZCdmHFTu0CQ8SRPHtDveAmnTt9WSPV/BTkQW+/i4= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731671AbfKPQOS (ORCPT ); Sat, 16 Nov 2019 11:14:18 -0500 Received: from mail.kernel.org ([198.145.29.99]:54652 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729825AbfKPPru (ORCPT ); Sat, 16 Nov 2019 10:47:50 -0500 Received: from sasha-vm.mshome.net (unknown [50.234.116.4]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 5F5A120729; Sat, 16 Nov 2019 15:47:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573919269; bh=XP4W78k7tWdh+OxHKfg/hOgoXSYlnsAKcT0blXHT8RY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=lbFPL8drc71o0hmABUxV0Nq0Cu7BHP2lhildgquyz9zZq7vLPAlZr1DwNyxorZA/D DzOsjrVovOmpjry4ep4++K3mFwWl1VUha8RE/mxcvtZQRBrlJ4Jgxk/M9i5yGyoV0r ezlNo/QT5LnG1ZqM/gcjToJvG6sk/ZtU9KddleTk= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wenwen Wang , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 4.14 019/150] misc: mic: fix a DMA pool free failure Date: Sat, 16 Nov 2019 10:45:17 -0500 Message-Id: <20191116154729.9573-19-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191116154729.9573-1-sashal@kernel.org> References: <20191116154729.9573-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore 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