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=-8.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,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 3CE21ECE564 for ; Tue, 18 Sep 2018 15:36:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D8E35214C2 for ; Tue, 18 Sep 2018 15:36:07 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org D8E35214C2 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=windriver.com 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 S1730072AbeIRVJL (ORCPT ); Tue, 18 Sep 2018 17:09:11 -0400 Received: from mail5.windriver.com ([192.103.53.11]:44718 "EHLO mail5.wrs.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729661AbeIRVJL (ORCPT ); Tue, 18 Sep 2018 17:09:11 -0400 Received: from ALA-HCA.corp.ad.wrs.com (ala-hca.corp.ad.wrs.com [147.11.189.40]) by mail5.wrs.com (8.15.2/8.15.2) with ESMTPS id w8IFXLdt009250 (version=TLSv1 cipher=AES128-SHA bits=128 verify=FAIL); Tue, 18 Sep 2018 08:33:32 -0700 Received: from pek-lpg-core2.corp.ad.wrs.com (128.224.153.41) by ALA-HCA.corp.ad.wrs.com (147.11.189.40) with Microsoft SMTP Server id 14.3.408.0; Tue, 18 Sep 2018 08:33:11 -0700 From: To: , , , , , , , , , CC: Subject: [PATCH] mm/page_alloc: Fix panic caused by passing debug_guardpage_minorder or kernelcore to command line Date: Tue, 18 Sep 2018 23:33:08 +0800 Message-ID: <1537284788-428784-1-git-send-email-zhe.he@windriver.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: He Zhe debug_guardpage_minorder_setup and cmdline_parse_kernelcore do not check input argument before using it. The argument would be a NULL pointer if "debug_guardpage_minorder" or "kernelcore", without its value, is set in command line and thus causes the following panic. PANIC: early exception 0xe3 IP 10:ffffffffa08146f1 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_option_str+0x11/0x90 ... [ 0.000000] Call Trace: [ 0.000000] cmdline_parse_kernelcore+0x19/0x41 [ 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 and adds KBUILD_MODNAME to prints. Signed-off-by: He Zhe Cc: stable@vger.kernel.org Cc: akpm@linux-foundation.org Cc: mhocko@suse.com Cc: vbabka@suse.cz Cc: pasha.tatashin@oracle.com Cc: mgorman@techsingularity.net Cc: aaron.lu@intel.com Cc: osalvador@suse.de Cc: iamjoonsoo.kim@lge.com --- mm/page_alloc.c | 12 ++++++++++++ 1 file changed, 12 insertions(+) diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 89d2a2a..d4cda06 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -14,6 +14,8 @@ * (lots of bits borrowed from Ingo Molnar & Andrew Morton) */ +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt + #include #include #include @@ -630,6 +632,11 @@ static int __init debug_guardpage_minorder_setup(char *buf) { unsigned long res; + if (!buf) { + pr_err("Config string not provided\n"); + return -EINVAL; + } + if (kstrtoul(buf, 10, &res) < 0 || res > MAX_ORDER / 2) { pr_err("Bad debug_guardpage_minorder value\n"); return 0; @@ -6952,6 +6959,11 @@ static int __init cmdline_parse_core(char *p, unsigned long *core, */ static int __init cmdline_parse_kernelcore(char *p) { + if (!p) { + pr_err("Config string not provided\n"); + return -EINVAL; + } + /* parse kernelcore=mirror */ if (parse_option_str(p, "mirror")) { mirrored_kernelcore = true; -- 2.7.4