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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,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 28298C2D0E4 for ; Tue, 24 Nov 2020 11:57:36 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C87842076E for ; Tue, 24 Nov 2020 11:57:35 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1733179AbgKXL5f (ORCPT ); Tue, 24 Nov 2020 06:57:35 -0500 Received: from szxga07-in.huawei.com ([45.249.212.35]:8398 "EHLO szxga07-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732852AbgKXL5e (ORCPT ); Tue, 24 Nov 2020 06:57:34 -0500 Received: from DGGEMS408-HUB.china.huawei.com (unknown [172.30.72.59]) by szxga07-in.huawei.com (SkyGuard) with ESMTP id 4CgMvV6254z71pC; Tue, 24 Nov 2020 19:57:10 +0800 (CST) Received: from huawei.com (10.175.124.27) by DGGEMS408-HUB.china.huawei.com (10.3.19.208) with Microsoft SMTP Server id 14.3.487.0; Tue, 24 Nov 2020 19:57:23 +0800 From: Wang ShaoBo To: CC: , , , , , Subject: [PATCH] kretprobe: avoid re-registration of the same kretprobe earlier Date: Tue, 24 Nov 2020 19:57:19 +0800 Message-ID: <20201124115719.11799-1-bobo.shaobowang@huawei.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.175.124.27] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Our system encountered a re-init error when re-registering same kretprobe, where the kretprobe_instance in rp->free_instances is illegally accessed after re-init. Implementation to avoid re-registration has been introduced for kprobe before, but lags for register_kretprobe(). We must check if kprobe has been re-registered before re-initializing kretprobe, otherwise it will destroy the data struct of kretprobe registered, which can lead to memory leak, system crash, also some unexpected behaviors. we use check_kprobe_rereg() to check if kprobe has been re-registered before calling register_kretprobe(), for giving a warning message and terminate registration process. Signed-off-by: Wang ShaoBo Signed-off-by: Cheng Jian --- kernel/kprobes.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/kernel/kprobes.c b/kernel/kprobes.c index 41fdbb7953c6..7f54a70136f3 100644 --- a/kernel/kprobes.c +++ b/kernel/kprobes.c @@ -2117,6 +2117,14 @@ int register_kretprobe(struct kretprobe *rp) } } + /* + * Return error if it's being re-registered, + * also give a warning message to the developer. + */ + ret = check_kprobe_rereg(&rp->kp); + if (WARN_ON(ret)) + return ret; + rp->kp.pre_handler = pre_handler_kretprobe; rp->kp.post_handler = NULL; rp->kp.fault_handler = NULL; -- 2.17.1