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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT 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 D7653C433E6 for ; Tue, 16 Mar 2021 19:39:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id A5BC764F3C for ; Tue, 16 Mar 2021 19:39:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S240500AbhCPTif (ORCPT ); Tue, 16 Mar 2021 15:38:35 -0400 Received: from relay10.mail.gandi.net ([217.70.178.230]:59913 "EHLO relay10.mail.gandi.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234578AbhCPTiY (ORCPT ); Tue, 16 Mar 2021 15:38:24 -0400 Received: from debian.home (lfbn-lyo-1-457-219.w2-7.abo.wanadoo.fr [2.7.49.219]) (Authenticated sender: alex@ghiti.fr) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 30ACF240006; Tue, 16 Mar 2021 19:38:21 +0000 (UTC) From: Alexandre Ghiti To: Rob Herring , Frank Rowand , Dmitry Vyukov , devicetree@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Alexandre Ghiti Subject: [PATCH] driver: of: Properly truncate command line if too long Date: Tue, 16 Mar 2021 15:38:20 -0400 Message-Id: <20210316193820.3137-1-alex@ghiti.fr> X-Mailer: git-send-email 2.20.1 MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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 -- 2.20.1