From patchwork Tue Mar 16 19:38:20 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexandre Ghiti X-Patchwork-Id: 1454202 Return-Path: X-Original-To: incoming-dt@patchwork.ozlabs.org Delivered-To: patchwork-incoming-dt@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=devicetree-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4F0Nrn5v8Lz9sVm for ; Wed, 17 Mar 2021 06:39:05 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S236896AbhCPTia (ORCPT ); Tue, 16 Mar 2021 15:38:30 -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 Precedence: bulk List-ID: X-Mailing-List: devicetree@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