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=-9.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=unavailable 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 937CFC64E7D for ; Tue, 17 Nov 2020 13:12:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5B849241A7 for ; Tue, 17 Nov 2020 13:12:12 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="bcgp/ZiA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729189AbgKQNMI (ORCPT ); Tue, 17 Nov 2020 08:12:08 -0500 Received: from mail.kernel.org ([198.145.29.99]:41790 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729258AbgKQNLw (ORCPT ); Tue, 17 Nov 2020 08:11:52 -0500 Received: from localhost (83-86-74-64.cable.dynamic.v4.ziggo.nl [83.86.74.64]) (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 405E624199; Tue, 17 Nov 2020 13:11:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1605618711; bh=xTAXFNREFzNiLURv6XXd01JKeNZ3ZXa4zHUHpNhRLEY=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=bcgp/ZiAgHQunXzaE5k4cI56XDg5fbNRGqWsDP1U/6GL17q3SoWhPraSFnCNpCLcG dMOeUJrBXPIZsnlWc4wEWrrsao/kK51yrjlpIveHNXSkgEZKbdNsmXMnDUzrfwGKl1 SSHv51Z/dkf5EPGaRK79DPAP+OUQ0iiRzsHFHiwM= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Mathieu Poirier , "Peter Zijlstra (Intel)" , Alexander Shishkin , Arnaldo Carvalho de Melo , Jiri Olsa , Linus Torvalds , Stephane Eranian , Thomas Gleixner , Vince Weaver , acme@kernel.org, miklos@szeredi.hu, namhyung@kernel.org, songliubraving@fb.com, Ingo Molnar , Sudip Mukherjee Subject: [PATCH 4.9 60/78] perf/core: Fix crash when using HW tracing kernel filters Date: Tue, 17 Nov 2020 14:05:26 +0100 Message-Id: <20201117122112.038248140@linuxfoundation.org> X-Mailer: git-send-email 2.29.2 In-Reply-To: <20201117122109.116890262@linuxfoundation.org> References: <20201117122109.116890262@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Mathieu Poirier commit 7f635ff187ab6be0b350b3ec06791e376af238ab upstream 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 Signed-off-by: Sudip Mukherjee Signed-off-by: Greg Kroah-Hartman --- kernel/events/core.c | 4 ++++ 1 file changed, 4 insertions(+) --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -6814,6 +6814,10 @@ static bool perf_addr_filter_match(struc 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;