From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752354AbaDROmg (ORCPT ); Fri, 18 Apr 2014 10:42:36 -0400 Received: from mail-qg0-f45.google.com ([209.85.192.45]:45223 "EHLO mail-qg0-f45.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751001AbaDROmd (ORCPT ); Fri, 18 Apr 2014 10:42:33 -0400 Date: Fri, 18 Apr 2014 10:45:47 -0400 (EDT) From: Vince Weaver To: Peter Zijlstra cc: Ingo Molnar , linux-kernel@vger.kernel.org, Thomas Gleixner , Steven Rostedt Subject: Re: [perf] more perf_fuzzer memory corruption In-Reply-To: <20140417145418.GM11096@twins.programming.kicks-ass.net> Message-ID: References: <20140416141514.GS11182@twins.programming.kicks-ass.net> <20140417094815.GA9348@gmail.com> <20140417114533.GJ11096@twins.programming.kicks-ass.net> <20140417142213.GA29338@gmail.com> <20140417145418.GM11096@twins.programming.kicks-ass.net> User-Agent: Alpine 2.10 (DEB 1266 2009-07-14) 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 OK, since the slab corruption was happening to event->hlist_entry->pprev I added a WARN() call to every modifier of pprev under include/linux/*list*.h to see what was stomping over freed memory. This is what came up: Apr 18 10:36:11 haswell kernel: [ 998.316177] ------------[ cut here ]------------ Apr 18 10:36:11 haswell kernel: [ 998.321188] WARNING: CPU: 3 PID: 20717 at include/linux/rculist.h:410 perf_trace_add+0xc1/0x100() Apr 18 10:36:11 haswell kernel: [ 998.330681] Modules linked in: fuse x86_pkg_temp_thermal intel_powerclamp coretemp snd_hda_codec_realtek snd_hda_codec_generic snd_hda_codec_hdmi kvm snd_hda_intel iTCO_wdt snd_hda_controller i915 snd_hda_codec evdev crct10dif_pclmul drm_kms_helper iTCO_vendor_support snd_hwdep snd_pcm drm crc32_pclmul snd_seq mei_me parport_pc parport lpc_ich mfd_core psmouse ghash_clmulni_intel snd_timer snd_seq_device mei snd aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd soundcore pcspkr serio_raw i2c_i801 processor video i2c_algo_bit i2c_core wmi button battery tpm_tis tpm sg sd_mod sr_mod crc_t10dif crct10dif_common cdrom ahci ehci_pci libahci xhci_hcd e1000e libata ehci_hcd ptp scsi_mod crc32c_intel usbcore pps_core usb_common fan thermal thermal_sys Apr 18 10:36:11 haswell kernel: [ 998.405736] CPU: 3 PID: 20717 Comm: perf_fuzzer Not tainted 3.15.0-rc1+ #63 Apr 18 10:36:11 haswell kernel: [ 998.413162] Hardware name: LENOVO 10AM000AUS/SHARKBAY, BIOS FBKT72AUS 01/26/2014 Apr 18 10:36:11 haswell kernel: [ 998.420987] 0000000000000009 ffff880117923c70 ffffffff8164f753 0000000000000000 Apr 18 10:36:11 haswell kernel: [ 998.429016] ffff880117923ca8 ffffffff810647cd ffffe8ffffcc30d8 ffff8800ce29f040 Apr 18 10:36:11 haswell kernel: [ 998.437121] ffffffff81c1ba40 ffff8800cd3d9040 000000da35b18e50 ffff880117923cb8 Apr 18 10:36:11 haswell kernel: [ 998.445246] Call Trace: Apr 18 10:36:11 haswell kernel: [ 998.447910] [] dump_stack+0x45/0x56 Apr 18 10:36:11 haswell kernel: [ 998.453451] [] warn_slowpath_common+0x7d/0xa0 Apr 18 10:36:11 haswell kernel: [ 998.459871] [] warn_slowpath_null+0x1a/0x20 Apr 18 10:36:11 haswell kernel: [ 998.466143] [] perf_trace_add+0xc1/0x100 Apr 18 10:36:11 haswell kernel: [ 998.472160] [] event_sched_in.isra.76+0x90/0x1e0 Apr 18 10:36:11 haswell kernel: [ 998.478849] [] group_sched_in+0x69/0x1e0 Apr 18 10:36:11 haswell kernel: [ 998.484812] [] __perf_event_enable+0x255/0x260 Apr 18 10:36:11 haswell kernel: [ 998.491370] [] remote_function+0x40/0x50 Apr 18 10:36:11 haswell kernel: [ 998.497311] [] generic_exec_single+0x126/0x170 Apr 18 10:36:11 haswell kernel: [ 998.503764] [] ? task_clock_event_add+0x40/0x40 Apr 18 10:36:11 haswell kernel: [ 998.510432] [] smp_call_function_single+0x67/0xa0 Apr 18 10:36:11 haswell kernel: [ 998.517299] [] task_function_call+0x44/0x50 Apr 18 10:36:11 haswell kernel: [ 998.523539] [] ? perf_event_sched_in+0x90/0x90 Apr 18 10:36:11 haswell kernel: [ 998.530085] [] perf_event_enable+0x90/0xf0 Apr 18 10:36:11 haswell kernel: [ 998.536308] [] ? task_function_call+0x50/0x50 Apr 18 10:36:11 haswell kernel: [ 998.542761] [] perf_event_for_each_child+0x3a/0xa0 Apr 18 10:36:11 haswell kernel: [ 998.551512] [] perf_event_task_enable+0x4f/0x80 Apr 18 10:36:11 haswell kernel: [ 998.560080] [] SyS_prctl+0x255/0x4b0 Apr 18 10:36:11 haswell kernel: [ 998.567605] [] ? lockdep_sys_exit_thunk+0x35/0x67 Apr 18 10:36:11 haswell kernel: [ 998.576333] [] system_call_fastpath+0x1a/0x1f Apr 18 10:36:11 haswell kernel: [ 998.584698] ---[ end trace b175966afd57a174 ]--- Apr 18 10:36:12 haswell kernel: [ 998.910691] ------------[ cut here ]------------