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=-6.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS 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 BAAC2ECE564 for ; Tue, 18 Sep 2018 15:51:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6ABA221471 for ; Tue, 18 Sep 2018 15:51:54 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 6ABA221471 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.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 S1730090AbeIRVZC (ORCPT ); Tue, 18 Sep 2018 17:25:02 -0400 Received: from mail.kernel.org ([198.145.29.99]:48890 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729249AbeIRVZC (ORCPT ); Tue, 18 Sep 2018 17:25:02 -0400 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (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 5627321471; Tue, 18 Sep 2018 15:51:51 +0000 (UTC) Date: Tue, 18 Sep 2018 11:51:49 -0400 From: Steven Rostedt To: Cc: , , Subject: Re: [PATCH] printk: Fix panic caused by passing log_buf_len to command line Message-ID: <20180918115149.46685fae@gandalf.local.home> In-Reply-To: <1537285354-430044-1-git-send-email-zhe.he@windriver.com> References: <1537285354-430044-1-git-send-email-zhe.he@windriver.com> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 18 Sep 2018 23:42:34 +0800 wrote: > From: He Zhe > > 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, adds KBUILD_MODNAME to > prints and correct bare use of 'unsigned'. Hi! The addition of pr_fmt and the unsigned update should be a separate patch. This is a bug fix and only the bug fix should be included, as it is going to be backported. Thanks! -- Steve > > Signed-off-by: He Zhe > Cc: stable@vger.kernel.org > Cc: pmladek@suse.com > Cc: sergey.senozhatsky@gmail.com > Cc: rostedt@goodmis.org > --- > kernel/printk/printk.c | 11 ++++++++++- > 1 file changed, 10 insertions(+), 1 deletion(-) > > diff --git a/kernel/printk/printk.c b/kernel/printk/printk.c > index 9bf5404..f6d4030 100644 > --- a/kernel/printk/printk.c > +++ b/kernel/printk/printk.c > @@ -16,6 +16,8 @@ > * 01Mar01 Andrew Morton > */ > > +#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt > + > #include > #include > #include > @@ -1048,7 +1050,14 @@ static void __init log_buf_len_update(unsigned size) > /* 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) { > + pr_err("Config string not provided\n"); > + return -EINVAL; > + } > + > + size = memparse(str, &str); > > log_buf_len_update(size); >