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 0A52EC43441 for ; Mon, 19 Nov 2018 17:04:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C75892148E for ; Mon, 19 Nov 2018 17:04:39 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="wXnjN7IO" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C75892148E 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 S2406601AbeKTD2z (ORCPT ); Mon, 19 Nov 2018 22:28:55 -0500 Received: from mail.kernel.org ([198.145.29.99]:43402 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2405880AbeKTD2y (ORCPT ); Mon, 19 Nov 2018 22:28:54 -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 8B0B5214D9; Mon, 19 Nov 2018 17:04:36 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1542647077; bh=oIJfj/0OTyV8QqAJN3G4Xgf/ywIvfGQsVnzNmmh0NmU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=wXnjN7IOdgXlZR9K17QjLCg4qbvQgMY3sU7zV96I1rV6lqCISQwbuVGyU6KRfUdIf g2RbbzFVbtsymFXz++bhsMusUxd4T5yvQzpGGSTOMhO+mEBxJ10eS/ORpx3mZQL9Pw QkPvabrufiZdkDnBxpO8AqZuHpvmTPd1AVfAhDt4= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, rostedt@goodmis.org, He Zhe , Sergey Senozhatsky , Petr Mladek Subject: [PATCH 3.18 42/90] printk: Fix panic caused by passing log_buf_len to command line Date: Mon, 19 Nov 2018 17:29:24 +0100 Message-Id: <20181119162627.543481335@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 277fcdb2cfee38ccdbe07e705dbd4896ba0c9930 upstream. log_buf_len_setup does not check input argument before passing it to simple_strtoull. The argument would be a NULL pointer if "log_buf_len", without its value, is set in command line and thus causes the following panic. PANIC: early exception 0xe3 IP 10:ffffffffaaeacd0d error 0 cr2 0x0 [ 0.000000] CPU: 0 PID: 0 Comm: swapper Not tainted 4.19.0-rc4-yocto-standard+ #1 [ 0.000000] RIP: 0010:_parse_integer_fixup_radix+0xd/0x70 ... [ 0.000000] Call Trace: [ 0.000000] simple_strtoull+0x29/0x70 [ 0.000000] memparse+0x26/0x90 [ 0.000000] log_buf_len_setup+0x17/0x22 [ 0.000000] do_early_param+0x57/0x8e [ 0.000000] parse_args+0x208/0x320 [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_options+0x29/0x2d [ 0.000000] ? rdinit_setup+0x30/0x30 [ 0.000000] parse_early_param+0x36/0x4d [ 0.000000] setup_arch+0x336/0x99e [ 0.000000] start_kernel+0x6f/0x4ee [ 0.000000] x86_64_start_reservations+0x24/0x26 [ 0.000000] x86_64_start_kernel+0x6f/0x72 [ 0.000000] secondary_startup_64+0xa4/0xb0 This patch adds a check to prevent the panic. Link: http://lkml.kernel.org/r/1538239553-81805-1-git-send-email-zhe.he@windriver.com Cc: stable@vger.kernel.org Cc: rostedt@goodmis.org Cc: linux-kernel@vger.kernel.org Signed-off-by: He Zhe Reviewed-by: Sergey Senozhatsky Signed-off-by: Petr Mladek Signed-off-by: Greg Kroah-Hartman --- kernel/printk/printk.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/kernel/printk/printk.c +++ b/kernel/printk/printk.c @@ -844,7 +844,12 @@ static void __init log_buf_len_update(un /* save requested log_buf_len since it's too early to process it */ static int __init log_buf_len_setup(char *str) { - unsigned size = memparse(str, &str); + unsigned int size; + + if (!str) + return -EINVAL; + + size = memparse(str, &str); log_buf_len_update(size);