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=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 09A3EC432C3 for ; Sat, 16 Nov 2019 15:59:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D69912089D for ; Sat, 16 Nov 2019 15:59:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573919984; bh=g8qwpXtgl8IM5Jzu0ga/wmRPoMvRpo/KhSdJYLHxgnk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=CdNEPuJhvy++EbYx/e56JL/KPiEFfeRdzxOhXsoYYkclfjQFZvL9nePKJR+B+n60b ZQYYxlergfoi0oO01JIVfMoyETi8VUDbuN+2tePL0i1wZFI1FrNOOIoPwy6srGixJD oSCKItoWSA4LhMaT0ryy9fHlWzJHQ0Y+gDBcwcEU= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730958AbfKPP7n (ORCPT ); Sat, 16 Nov 2019 10:59:43 -0500 Received: from mail.kernel.org ([198.145.29.99]:35220 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1731333AbfKPPxy (ORCPT ); Sat, 16 Nov 2019 10:53:54 -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 76E902184B; Sat, 16 Nov 2019 15:53:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573919633; bh=g8qwpXtgl8IM5Jzu0ga/wmRPoMvRpo/KhSdJYLHxgnk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=MiISpFT/2UsTGfXDndiy2fp78fMbNlt7GpTOUBFtyjW9hmNqPxCwXEFm2XCwUxDS0 hTY9H+pgMTys2OgG/DeRee71iNVwUFbGS3Sk3j77agR5tBE8NMGpjPVUgvk8Ooc619 8Q2mm/QA7b3naG/1RE48/p0UCF5xr/mLjkP1SBho= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Wenwen Wang , Greg Kroah-Hartman , Sasha Levin Subject: [PATCH AUTOSEL 4.4 12/77] misc: mic: fix a DMA pool free failure Date: Sat, 16 Nov 2019 10:52:34 -0500 Message-Id: <20191116155339.11909-12-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20191116155339.11909-1-sashal@kernel.org> References: <20191116155339.11909-1-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 7f2c96f570667..6821d9d415854 100644 --- a/drivers/misc/mic/scif/scif_fence.c +++ b/drivers/misc/mic/scif/scif_fence.c @@ -271,7 +271,7 @@ 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