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=-7.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham 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 53DAFC43441 for ; Mon, 19 Nov 2018 17:04:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 19AEC214F1 for ; Mon, 19 Nov 2018 17:04:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="c4/Q/2u0" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 19AEC214F1 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linuxfoundation.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2406685AbeKTD3N (ORCPT ); Mon, 19 Nov 2018 22:29:13 -0500 Received: from mail.kernel.org ([198.145.29.99]:43820 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405697AbeKTD3M (ORCPT ); Mon, 19 Nov 2018 22:29:12 -0500 Received: from localhost (5356596B.cm-6-7b.dynamic.ziggo.nl [83.86.89.107]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id AFF3F214D9; Mon, 19 Nov 2018 17:04:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542647095; bh=YhFszXDdqkri+ZuSUof6JDN+K5ULojcWRYoHSWC4Baw=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=c4/Q/2u0UPCtIhp9FtH7zkthotZcRx7X1qDwcG0C0SsO41XvNe1ivPdx4BcXMahre PNp39NQgLJavMrPWVne06vPYP8CLje42lB639bdmSqo3UlzNXtoZaOASD7ObG5dUIL UVuhI8Okpor+UmhrTl2BN0PkW2uOoLuh9LpwmUrg= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, jason.wessel@windriver.com, jslaby@suse.com, He Zhe , Daniel Thompson Subject: [PATCH 3.18 48/90] kgdboc: Passing ekgdboc to command line causes panic Date: Mon, 19 Nov 2018 17:29:30 +0100 Message-Id: <20181119162628.576084176@linuxfoundation.org> X-Mailer: git-send-email 2.19.1 In-Reply-To: <20181119162620.585061184@linuxfoundation.org> References: <20181119162620.585061184@linuxfoundation.org> User-Agent: quilt/0.65 X-stable: review MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: He Zhe commit 1bd54d851f50dea6af30c3e6ff4f3e9aab5558f9 upstream. kgdboc_option_setup does not check input argument before passing it to strlen. The argument would be a NULL pointer if "ekgdboc", without its value, is set in command line and thus cause the following panic. PANIC: early exception 0xe3 IP 10:ffffffff8fbbb620 error 0 cr2 0x0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.18-rc8+ #1 [ 0.000000] RIP: 0010:strlen+0x0/0x20 ... [ 0.000000] Call Trace [ 0.000000] ? kgdboc_option_setup+0x9/0xa0 [ 0.000000] ? kgdboc_early_init+0x6/0x1b [ 0.000000] ? do_early_param+0x4d/0x82 [ 0.000000] ? parse_args+0x212/0x330 [ 0.000000] ? rdinit_setup+0x26/0x26 [ 0.000000] ? parse_early_options+0x20/0x23 [ 0.000000] ? rdinit_setup+0x26/0x26 [ 0.000000] ? parse_early_param+0x2d/0x39 [ 0.000000] ? setup_arch+0x2f7/0xbf4 [ 0.000000] ? start_kernel+0x5e/0x4c2 [ 0.000000] ? load_ucode_bsp+0x113/0x12f [ 0.000000] ? secondary_startup_64+0xa5/0xb0 This patch adds a check to prevent the panic. Cc: stable@vger.kernel.org Cc: jason.wessel@windriver.com Cc: gregkh@linuxfoundation.org Cc: jslaby@suse.com Signed-off-by: He Zhe Reviewed-by: Daniel Thompson Signed-off-by: Greg Kroah-Hartman --- drivers/tty/serial/kgdboc.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/tty/serial/kgdboc.c +++ b/drivers/tty/serial/kgdboc.c @@ -133,6 +133,11 @@ static void kgdboc_unregister_kbd(void) static int kgdboc_option_setup(char *opt) { + if (!opt) { + pr_err("kgdboc: config string not provided\n"); + return -EINVAL; + } + if (strlen(opt) >= MAX_CONFIG_LEN) { printk(KERN_ERR "kgdboc: config string too long\n"); return -ENOSPC;