From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751595AbeEQL5z (ORCPT ); Thu, 17 May 2018 07:57:55 -0400 Received: from mx2.suse.de ([195.135.220.15]:56441 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751047AbeEQL5y (ORCPT ); Thu, 17 May 2018 07:57:54 -0400 Date: Thu, 17 May 2018 13:57:52 +0200 From: Petr Mladek To: Tetsuo Handa Cc: sergey.senozhatsky.work@gmail.com, dvyukov@google.com, sergey.senozhatsky@gmail.com, syzkaller@googlegroups.com, rostedt@goodmis.org, fengguang.wu@intel.com, linux-kernel@vger.kernel.org, peterz@infradead.org Subject: Re: [PATCH] printk: fix possible reuse of va_list variable Message-ID: <20180517115752.iiatw77riws2vozb@pathway.suse.cz> References: <201805102350.JJH73950.tVJHQLFSOMOOFF@I-love.SAKURA.ne.jp> <20180511014515.GA895@jagdpanzerIV> <201805110238.w4B2cIGH079602@www262.sakura.ne.jp> <20180511062151.GA18160@jagdpanzerIV> <201805112002.GIF21216.OFVHFOMLJtQFSO@I-love.SAKURA.ne.jp> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <201805112002.GIF21216.OFVHFOMLJtQFSO@I-love.SAKURA.ne.jp> User-Agent: NeoMutt/20170421 (1.8.2) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri 2018-05-11 20:02:31, Tetsuo Handa wrote: > >From 766cf72b5fdc00d1cf5a8ca2c6b23ebb75e2b4d4 Mon Sep 17 00:00:00 2001 > From: Tetsuo Handa > Date: Fri, 11 May 2018 19:54:19 +0900 > Subject: [PATCH] printk: fix possible reuse of va_list variable > > I noticed that there is a possibility that printk_safe_log_store() causes > kernel oops because "args" parameter is passed to vsnprintf() again when > atomic_cmpxchg() detected that we raced. Fix this by using va_copy(). Great catch! Reviewed-by: Petr Mladek I have tagged it for stable and pushed into printk.git, branch for-4.18, see https://git.kernel.org/pub/scm/linux/kernel/git/pmladek/printk.git/commit/?h=for-4.18&id=988a35f8da1dec5a8cd2788054d1e717be61bf25 Best Regards, Petr