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=-11.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,USER_AGENT_GIT 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 B8012C433DB for ; Wed, 17 Mar 2021 10:26:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6838464E09 for ; Wed, 17 Mar 2021 10:26:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229893AbhCQK0V (ORCPT ); Wed, 17 Mar 2021 06:26:21 -0400 Received: from szxga07-in.huawei.com ([45.249.212.35]:14361 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229863AbhCQKZ5 (ORCPT ); Wed, 17 Mar 2021 06:25:57 -0400 Received: from DGGEMS413-HUB.china.huawei.com (unknown [172.30.72.58]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4F0mTp1w7lz9s00; Wed, 17 Mar 2021 18:23:58 +0800 (CST) Received: from ubuntu1804.huawei.com (10.67.174.174) by DGGEMS413-HUB.china.huawei.com (10.3.19.213) with Microsoft SMTP Server id 14.3.498.0; Wed, 17 Mar 2021 18:25:40 +0800 From: Li Huafei To: , , CC: , , , , Subject: [PATCH 0/2] Fix the race on &event->ftrace_ops between perf and ftrace Date: Wed, 17 Mar 2021 18:25:27 +0800 Message-ID: <20210317102529.226734-1-lihuafei1@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.67.174.174] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org There is a race on &event->ftrace_ops between perf_alloc_event() and __ftrace_ops_list_func(). When adding a perf event, if the event needs to use the ftrace framework, it needs to register ftrace_ops with ftrace, which is a structural member of perf event. If perf_alloc_event() fails, it will free the allocated event directly, but if ftrace_ops has been successfully registered, and the probe point is triggered, then __ftrace_ops_list_func() may still reference the ftrace_ops that perf just registered, but it has been freed with the event is freed, so use-after-free happens. This race condition was triggered when we did the fuzz test, see the commit message of PATCH 2 for detailed logs. This patch set fixes this race. Li Huafei (2): ftrace: Update ftrace_ops->next pointer with rcu_assign_pointer() perf, ftrace: Fix use-after-free in __ftrace_ops_list_func() include/linux/ftrace.h | 15 +++++++++++++++ kernel/trace/ftrace.c | 4 ++-- kernel/trace/trace_event_perf.c | 7 +++++++ 3 files changed, 24 insertions(+), 2 deletions(-) -- 2.17.1