Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S935070AbcKXRdz (ORCPT ); Thu, 24 Nov 2016 12:33:55 -0500 Received: from mail-io0-f195.google.com ([209.85.223.195]:36245 "EHLO mail-io0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932959AbcKXRdx (ORCPT ); Thu, 24 Nov 2016 12:33:53 -0500 From: Vince Weaver X-Google-Original-From: Vince Weaver Date: Thu, 24 Nov 2016 12:33:48 -0500 (EST) X-X-Sender: vince@macbook-air To: "linux-kernel@vger.kernel.org" cc: Peter Zijlstra , Josh Poimboeuf , Ingo Molnar , Arnaldo Carvalho de Melo , "dvyukov@google.com" Subject: perf: fuzzer BUG: KASAN: stack-out-of-bounds in __unwind_start Message-ID: User-Agent: Alpine 2.20 (DEB 67 2015-01-07) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2076 Lines: 34 This is on a skylake machine, linus git as of yesterday after the various kasan-related fixes went in. Not sure if there were any that hadn't hit upstream yet. Anyway I can't tell from this one what the actual trigger is. After this mess the fuzzer process was locked, udev started complaining, and it eventually died completely after a few hours of repeated messages like this. [38898.373183] INFO: rcu_sched self-detected stall on CPU [38898.378452] 7-...: (5249 ticks this GP) idle=727/140000000000001/0 softirq=3141908/3141908 fqs=2625 [38898.381211] INFO: rcu_sched detected stalls on CPUs/tasks: [38898.381214] 0-...: (1 GPs behind) idle=05f/140000000000001/2 softirq=3285458/3285459 fqs=2625 [38898.381217] 7-...: (5249 ticks this GP) idle=727/140000000000001/0 softirq=3141908/3141908 fqs=2625 [38898.381218] (detected by 1, t=5252 jiffies, g=3685053, c=3685052, q=32) [38898.381244] ================================================================== [38898.381247] BUG: KASAN: stack-out-of-bounds in __unwind_start+0x1a2/0x1c0 at addr ffff8801e9727c28 [38898.381248] Read of size 8 by task swapper/1/0 [38898.381250] page:ffffea0007a5c9c0 count:0 mapcount:0 mapping: (null) index:0x0 [38898.381251] flags: 0x2ffff8000000000() [38898.381251] page dumped because: kasan: bad access detected [38898.381328] Memory state around the buggy address: [38898.381330] ffff8801e9727b00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [38898.381331] ffff8801e9727b80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 [38898.381332] >ffff8801e9727c00: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 f3 f3 f3 f3 [38898.381333] ^ [38898.381334] ffff8801e9727c80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 f1 [38898.381335] ffff8801e9727d00: f1 f1 f1 00 00 00 f4 f2 f2 f2 f2 00 00 00 00 f3 [38898.381335] ================================================================== [38898.510702] (t=5284 jiffies g=3685053 c=3685052 q=32) (That's all, the report above repeats but no useful things like a backtrace are ever printed)