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=-15.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 CDCFBC433B4 for ; Tue, 6 Apr 2021 14:53:21 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id AA317613B8 for ; Tue, 6 Apr 2021 14:53:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1345331AbhDFOx2 (ORCPT ); Tue, 6 Apr 2021 10:53:28 -0400 Received: from relay11.mail.gandi.net ([217.70.178.231]:42563 "EHLO relay11.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239488AbhDFOx1 (ORCPT ); Tue, 6 Apr 2021 10:53:27 -0400 Received: from [192.168.1.12] (lfbn-lyo-1-457-219.w2-7.abo.wanadoo.fr [2.7.49.219]) (Authenticated sender: alex@ghiti.fr) by relay11.mail.gandi.net (Postfix) with ESMTPSA id 7EA9D100008; Tue, 6 Apr 2021 14:53:17 +0000 (UTC) Subject: Re: [PATCH] driver: of: Properly truncate command line if too long To: Rob Herring Cc: Frank Rowand , Dmitry Vyukov , devicetree@vger.kernel.org, "linux-kernel@vger.kernel.org" References: <20210316193820.3137-1-alex@ghiti.fr> From: Alex Ghiti Message-ID: Date: Tue, 6 Apr 2021 10:53:17 -0400 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.9.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: fr Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Le 4/6/21 à 9:40 AM, Rob Herring a écrit : > On Sat, Apr 3, 2021 at 7:09 AM Alex Ghiti wrote: >> >> Hi, >> >> Le 3/16/21 à 3:38 PM, Alexandre Ghiti a écrit : >>> In case the command line given by the user is too long, warn about it >>> and truncate it to the last full argument. >>> >>> This is what efi already does in commit 80b1bfe1cb2f ("efi/libstub: >>> Don't parse overlong command lines"). >>> >>> Reported-by: Dmitry Vyukov >>> Signed-off-by: Alexandre Ghiti >>> --- >>> drivers/of/fdt.c | 21 ++++++++++++++++++++- >>> 1 file changed, 20 insertions(+), 1 deletion(-) >>> >>> diff --git a/drivers/of/fdt.c b/drivers/of/fdt.c >>> index dcc1dd96911a..de4c6f9bac39 100644 >>> --- a/drivers/of/fdt.c >>> +++ b/drivers/of/fdt.c >>> @@ -25,6 +25,7 @@ >>> #include >>> #include >>> #include >>> +#include >>> >>> #include /* for COMMAND_LINE_SIZE */ >>> #include >>> @@ -1050,9 +1051,27 @@ int __init early_init_dt_scan_chosen(unsigned long node, const char *uname, >>> >>> /* Retrieve command line */ >>> p = of_get_flat_dt_prop(node, "bootargs", &l); >>> - if (p != NULL && l > 0) >>> + if (p != NULL && l > 0) { >>> strlcpy(data, p, min(l, COMMAND_LINE_SIZE)); >>> >>> + /* >>> + * If the given command line size is larger than >>> + * COMMAND_LINE_SIZE, truncate it to the last complete >>> + * parameter. >>> + */ >>> + if (l > COMMAND_LINE_SIZE) { >>> + char *cmd_p = (char *)data + COMMAND_LINE_SIZE - 1; >>> + >>> + while (!isspace(*cmd_p)) >>> + cmd_p--; >>> + >>> + *cmd_p = '\0'; >>> + >>> + pr_err("Command line is too long: truncated to %d bytes\n", >>> + (int)(cmd_p - (char *)data + 1)); >>> + } >>> + } >>> + >>> /* >>> * CONFIG_CMDLINE is meant to be a default in case nothing else >>> * managed to set the command line, unless CONFIG_CMDLINE_FORCE >>> >> >> Any thought about that ? > > It looks fine to me, but this will need to be adapted to the generic > command line support[1][2] when that is merged. So I've been waiting > to see if that's going to happen this cycle. Ok I'll take a look then, thanks. Alex > > Rob > > [1] https://lore.kernel.org/lkml/cover.1616765869.git.christophe.leroy@csgroup.eu/ > [2] https://lore.kernel.org/lkml/41021d66db2ab427c14255d2a24bb4517c8b58fd.1617126961.git.danielwa@cisco.com/ >