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=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 7498DC10F25 for ; Fri, 6 Mar 2020 09:28:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 56B622070A for ; Fri, 6 Mar 2020 09:28:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726261AbgCFJ2B (ORCPT ); Fri, 6 Mar 2020 04:28:01 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:34148 "EHLO huawei.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1726054AbgCFJ2B (ORCPT ); Fri, 6 Mar 2020 04:28:01 -0500 Received: from DGGEMS405-HUB.china.huawei.com (unknown [172.30.72.58]) by Forcepoint Email with ESMTP id 531A4C252A699F9FD0B1; Fri, 6 Mar 2020 17:27:58 +0800 (CST) Received: from huawei.com (10.90.53.225) by DGGEMS405-HUB.china.huawei.com (10.3.19.205) with Microsoft SMTP Server id 14.3.439.0; Fri, 6 Mar 2020 17:27:52 +0800 From: Cheng Jian To: CC: , , , , , , , Subject: [PATCH] kretprobe: check re-registration of the same kretprobe earlier Date: Fri, 6 Mar 2020 17:35:06 +0800 Message-ID: <1583487306-81985-1-git-send-email-cj.chengjian@huawei.com> X-Mailer: git-send-email 2.7.4 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.90.53.225] X-CFilter-Loop: Reflected Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Our system encountered a use-after-free when re-register a same kretprobe. it access the hlist node in rp->free_instances which has been released already. Prevent re-registration has been implemented for kprobe before, but it's too late for kretprobe. We must check the re-registration before re-initializing the kretprobe, otherwise it will destroy the data and struct of the kretprobe registered, it can lead to memory leak and use-after-free. Signed-off-by: Cheng Jian --- kernel/kprobes.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 2625c24..f1fc921 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -1946,6 +1946,11 @@ int register_kretprobe(struct kretprobe *rp) } } + /* Return error if it's being re-registered */ + ret = check_kprobe_rereg(&rp->kp); + if (ret) + return ret; + rp->kp.pre_handler = pre_handler_kretprobe; rp->kp.post_handler = NULL; rp->kp.fault_handler = NULL; -- 2.7.4