From patchwork Wed Feb 28 20:52:36 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 10249705 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id C643E60362 for ; Wed, 28 Feb 2018 20:53:02 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id B738528CBD for ; Wed, 28 Feb 2018 20:53:02 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id AB91328D6C; Wed, 28 Feb 2018 20:53:02 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 560AC28CBD for ; Wed, 28 Feb 2018 20:53:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934799AbeB1Uw7 (ORCPT ); Wed, 28 Feb 2018 15:52:59 -0500 Received: from galahad.ideasonboard.com ([185.26.127.97]:44484 "EHLO galahad.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934767AbeB1Uwz (ORCPT ); Wed, 28 Feb 2018 15:52:55 -0500 Received: from localhost.localdomain (cpc89242-aztw30-2-0-cust488.18-1.cable.virginm.net [86.31.129.233]) by galahad.ideasonboard.com (Postfix) with ESMTPSA id DCDA9203A0; Wed, 28 Feb 2018 21:51:00 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1519851061; bh=OxpTdKio+G8qwDzuqeSs8CFXKC9ZIyiIACLtwpdkQjM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:In-Reply-To: References:From; b=pQBvfedZ1085VlGgnyXnXVzO7Io+LRrG2EjSvz0j9TzApHMUsS/MVp6XEOhqteT87 A1F9N/jkOaVBNAva/efFOaajdp4gZMbyCbFAV+LPgu4p0jep59eeavlOL+r5a5C2On ZWtczm0Ya3mdB7FBG0r8P+AsuQbie+wBXObhEGQA= From: Kieran Bingham To: Laurent Pinchart , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org Cc: Kieran Bingham Subject: [PATCH v6 2/9] v4l: vsp1: Protect bodies against overflow Date: Wed, 28 Feb 2018 20:52:36 +0000 Message-Id: X-Mailer: git-send-email 2.7.4 In-Reply-To: References: In-Reply-To: References: Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP The body write function relies on the code never asking it to write more than the entries available in the list. Currently with each list body containing 256 entries, this is fine, but we can reduce this number greatly saving memory. In preparation of this add a level of protection to catch any buffer overflows. Signed-off-by: Kieran Bingham Reviewed-by: Laurent Pinchart --- v3: - adapt for new 'body' terminology - simplify WARN_ON macro usage drivers/media/platform/vsp1/vsp1_dl.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/drivers/media/platform/vsp1/vsp1_dl.c b/drivers/media/platform/vsp1/vsp1_dl.c index 0c1bd17f9281..59fe80bf6e9d 100644 --- a/drivers/media/platform/vsp1/vsp1_dl.c +++ b/drivers/media/platform/vsp1/vsp1_dl.c @@ -50,6 +50,7 @@ struct vsp1_dl_entry { * @dma: DMA address of the entries * @size: size of the DMA memory in bytes * @num_entries: number of stored entries + * @max_entries: number of entries available */ struct vsp1_dl_body { struct list_head list; @@ -60,6 +61,7 @@ struct vsp1_dl_body { size_t size; unsigned int num_entries; + unsigned int max_entries; }; /** @@ -139,6 +141,7 @@ static int vsp1_dl_body_init(struct vsp1_device *vsp1, dlb->vsp1 = vsp1; dlb->size = size; + dlb->max_entries = num_entries; dlb->entries = dma_alloc_wc(vsp1->bus_master, dlb->size, &dlb->dma, GFP_KERNEL); @@ -220,6 +223,10 @@ void vsp1_dl_body_free(struct vsp1_dl_body *dlb) */ void vsp1_dl_body_write(struct vsp1_dl_body *dlb, u32 reg, u32 data) { + if (WARN_ONCE(dlb->num_entries >= dlb->max_entries, + "DLB size exceeded (max %u)", dlb->max_entries)) + return; + dlb->entries[dlb->num_entries].addr = reg; dlb->entries[dlb->num_entries].data = data; dlb->num_entries++;