From patchwork Tue Nov 5 10:01:41 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mauro Carvalho Chehab X-Patchwork-Id: 3141271 Return-Path: X-Original-To: patchwork-linux-media@patchwork.kernel.org Delivered-To: patchwork-parsemail@patchwork2.web.kernel.org Received: from mail.kernel.org (mail.kernel.org [198.145.19.201]) by patchwork2.web.kernel.org (Postfix) with ESMTP id 2FB47BEEB2 for ; Tue, 5 Nov 2013 13:05:06 +0000 (UTC) Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 7D1FB2061E for ; Tue, 5 Nov 2013 13:05:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 59E1120580 for ; Tue, 5 Nov 2013 13:05:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754868Ab3KENEh (ORCPT ); Tue, 5 Nov 2013 08:04:37 -0500 Received: from bombadil.infradead.org ([198.137.202.9]:43283 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754632Ab3KENDt (ORCPT ); Tue, 5 Nov 2013 08:03:49 -0500 Received: from [177.143.133.66] (helo=smtp.w2.samsung.com) by bombadil.infradead.org with esmtpsa (Exim 4.80.1 #2 (Red Hat Linux)) id 1VdgIO-0007gM-Db; Tue, 05 Nov 2013 13:03:49 +0000 Received: from mchehab by smtp.w2.samsung.com with local (Exim 4.80.1) (envelope-from ) id 1VddSC-00080s-Gt; Tue, 05 Nov 2013 08:01:44 -0200 From: Mauro Carvalho Chehab Cc: Mauro Carvalho Chehab , Linux Media Mailing List , Mauro Carvalho Chehab Subject: [PATCH v3 28/29] [media] lirc_zilog: Don't use dynamic static allocation Date: Tue, 5 Nov 2013 08:01:41 -0200 Message-Id: <1383645702-30636-29-git-send-email-m.chehab@samsung.com> X-Mailer: git-send-email 1.8.3.1 In-Reply-To: <1383645702-30636-1-git-send-email-m.chehab@samsung.com> References: <1383645702-30636-1-git-send-email-m.chehab@samsung.com> To: unlisted-recipients:; (no To-header on input) Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Spam-Status: No, score=-6.9 required=5.0 tests=BAYES_00, RCVD_IN_DNSWL_HI, RP_MATCHES_RCVD, UNPARSEABLE_RELAY autolearn=ham version=3.3.1 X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on mail.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Dynamic static allocation is evil, as Kernel stack is too low, and ompilation complains about it on some archs: drivers/staging/media/lirc/lirc_zilog.c:967:1: warning: 'read' uses dynamic stack allocation [enabled by default] Instead, let's enforce a limit for the buffer to be 64. That should be more than enough. Signed-off-by: Mauro Carvalho Chehab --- drivers/staging/media/lirc/lirc_zilog.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/drivers/staging/media/lirc/lirc_zilog.c b/drivers/staging/media/lirc/lirc_zilog.c index 11d5338b4f2f..0feeaadf29dc 100644 --- a/drivers/staging/media/lirc/lirc_zilog.c +++ b/drivers/staging/media/lirc/lirc_zilog.c @@ -61,6 +61,9 @@ #include #include +/* Max transfer size done by I2C transfer functions */ +#define MAX_XFER_SIZE 64 + struct IR; struct IR_rx { @@ -941,7 +944,14 @@ static ssize_t read(struct file *filep, char *outbuf, size_t n, loff_t *ppos) schedule(); set_current_state(TASK_INTERRUPTIBLE); } else { - unsigned char buf[rbuf->chunk_size]; + unsigned char buf[MAX_XFER_SIZE]; + + if (rbuf->chunk_size > sizeof(buf)) { + zilog_error("chunk_size is too big (%d)!\n", + rbuf->chunk_size); + ret = -EINVAL; + break; + } m = lirc_buffer_read(rbuf, buf); if (m == rbuf->chunk_size) { ret = copy_to_user((void *)outbuf+written, buf,