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=-0.8 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 342EAC6778F for ; Wed, 25 Jul 2018 14:32:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E6D8F20852 for ; Wed, 25 Jul 2018 14:32:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E6D8F20852 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=zytor.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 S1729110AbeGYPnz (ORCPT ); Wed, 25 Jul 2018 11:43:55 -0400 Received: from terminus.zytor.com ([198.137.202.136]:37417 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728051AbeGYPnz (ORCPT ); Wed, 25 Jul 2018 11:43:55 -0400 Received: from terminus.zytor.com (localhost [127.0.0.1]) by terminus.zytor.com (8.15.2/8.15.2) with ESMTPS id w6PEVNN8402926 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 25 Jul 2018 07:31:23 -0700 Received: (from tipbot@localhost) by terminus.zytor.com (8.15.2/8.15.2/Submit) id w6PEVNwm402923; Wed, 25 Jul 2018 07:31:23 -0700 Date: Wed, 25 Jul 2018 07:31:23 -0700 X-Authentication-Warning: terminus.zytor.com: tipbot set sender to tipbot@zytor.com using -f From: tip-bot for Mathieu Poirier Message-ID: Cc: linux-kernel@vger.kernel.org, vincent.weaver@maine.edu, mingo@kernel.org, peterz@infradead.org, hpa@zytor.com, acme@redhat.com, mathieu.poirier@linaro.org, tglx@linutronix.de, alexander.shishkin@linux.intel.com, eranian@google.com, jolsa@redhat.com, torvalds@linux-foundation.org Reply-To: mathieu.poirier@linaro.org, tglx@linutronix.de, acme@redhat.com, linux-kernel@vger.kernel.org, mingo@kernel.org, hpa@zytor.com, peterz@infradead.org, vincent.weaver@maine.edu, torvalds@linux-foundation.org, eranian@google.com, jolsa@redhat.com, alexander.shishkin@linux.intel.com In-Reply-To: <1531782831-1186-1-git-send-email-mathieu.poirier@linaro.org> References: <1531782831-1186-1-git-send-email-mathieu.poirier@linaro.org> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf/core: Fix crash when using HW tracing kernel filters Git-Commit-ID: 7f635ff187ab6be0b350b3ec06791e376af238ab X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: 7f635ff187ab6be0b350b3ec06791e376af238ab Gitweb: https://git.kernel.org/tip/7f635ff187ab6be0b350b3ec06791e376af238ab Author: Mathieu Poirier AuthorDate: Mon, 16 Jul 2018 17:13:51 -0600 Committer: Ingo Molnar CommitDate: Wed, 25 Jul 2018 11:46:22 +0200 perf/core: Fix crash when using HW tracing kernel filters In function perf_event_parse_addr_filter(), the path::dentry of each struct perf_addr_filter is left unassigned (as it should be) when the pattern being parsed is related to kernel space. But in function perf_addr_filter_match() the same dentries are given to d_inode() where the value is not expected to be NULL, resulting in the following splat: Unable to handle kernel NULL pointer dereference at virtual address 0000000000000058 pc : perf_event_mmap+0x2fc/0x5a0 lr : perf_event_mmap+0x2c8/0x5a0 Process uname (pid: 2860, stack limit = 0x000000001cbcca37) Call trace: perf_event_mmap+0x2fc/0x5a0 mmap_region+0x124/0x570 do_mmap+0x344/0x4f8 vm_mmap_pgoff+0xe4/0x110 vm_mmap+0x2c/0x40 elf_map+0x60/0x108 load_elf_binary+0x450/0x12c4 search_binary_handler+0x90/0x290 __do_execve_file.isra.13+0x6e4/0x858 sys_execve+0x3c/0x50 el0_svc_naked+0x30/0x34 This patch is fixing the problem by introducing a new check in function perf_addr_filter_match() to see if the filter's dentry is NULL. Signed-off-by: Mathieu Poirier Signed-off-by: Peter Zijlstra (Intel) Acked-by: Alexander Shishkin Cc: Arnaldo Carvalho de Melo Cc: Jiri Olsa Cc: Linus Torvalds Cc: Peter Zijlstra Cc: Stephane Eranian Cc: Thomas Gleixner Cc: Vince Weaver Cc: acme@kernel.org Cc: miklos@szeredi.hu Cc: namhyung@kernel.org Cc: songliubraving@fb.com Fixes: 9511bce9fe8e ("perf/core: Fix bad use of igrab()") Link: http://lkml.kernel.org/r/1531782831-1186-1-git-send-email-mathieu.poirier@linaro.org Signed-off-by: Ingo Molnar --- kernel/events/core.c | 4 ++++ 1 file changed, 4 insertions(+) diff --git a/kernel/events/core.c b/kernel/events/core.c index cdb32cf8e33c..eec2d5fb676b 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -7337,6 +7337,10 @@ static bool perf_addr_filter_match(struct perf_addr_filter *filter, struct file *file, unsigned long offset, unsigned long size) { + /* d_inode(NULL) won't be equal to any mapped user-space file */ + if (!filter->path.dentry) + return false; + if (d_inode(filter->path.dentry) != file_inode(file)) return false;