From patchwork Fri Nov 17 15:47:25 2017 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Kieran Bingham X-Patchwork-Id: 10062931 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 F2FAC601D3 for ; Fri, 17 Nov 2017 15:47:44 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E63D72AC03 for ; Fri, 17 Nov 2017 15:47:44 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id DB2112AC41; Fri, 17 Nov 2017 15:47:44 +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=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=unavailable 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 9BB902AC03 for ; Fri, 17 Nov 2017 15:47:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965772AbdKQPrm (ORCPT ); Fri, 17 Nov 2017 10:47:42 -0500 Received: from mail.kernel.org ([198.145.29.99]:58538 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S965332AbdKQPrk (ORCPT ); Fri, 17 Nov 2017 10:47:40 -0500 Received: from localhost.localdomain (cpc89242-aztw30-2-0-cust488.18-1.cable.virginm.net [86.31.129.233]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id D2F5A2192C; Fri, 17 Nov 2017 15:47:38 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D2F5A2192C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=ideasonboard.com Authentication-Results: mail.kernel.org; spf=fail smtp.mailfrom=kieran.bingham+renesas@ideasonboard.com From: Kieran Bingham To: laurent.pinchart@ideasonboard.com, kieran.bingham@ideasonboard.com Cc: linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, Kieran Bingham Subject: [PATCH v4 2/9] v4l: vsp1: Protect bodies against overflow Date: Fri, 17 Nov 2017 15:47:25 +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 643f7ea3af24..a45d35aa676e 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; }; /** @@ -138,6 +140,7 @@ 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); @@ -219,6 +222,10 @@ 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++;