From patchwork Fri Jun 19 14:32:25 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 223735 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=DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, 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 82E18C433E0 for ; Fri, 19 Jun 2020 16:34:57 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 5D98021527 for ; Fri, 19 Jun 2020 16:34:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592584497; bh=REYmcY8cxaI9Sz3+PaxzgBVhHq/qpIHIa00Ix67ORNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=e32mrZZVtbIjvxyNi6faBJHWbJRy8Xs+bECUiS0ESMlw0N7tF5JinHMDXA7NQ9/+r JzV2nwYoLOt+fCpemFroKQu/NIgY24DRqvY23dtrUQ86w3cmtlktZa5tQuZjDmIHgq DnUoOOmmIixuZEwMa0a8MFn6WbGi1W/jyw+kZHcs= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389308AbgFSOu0 (ORCPT ); Fri, 19 Jun 2020 10:50:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:43284 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389301AbgFSOuX (ORCPT ); Fri, 19 Jun 2020 10:50:23 -0400 Received: from localhost (83-86-89-107.cable.dynamic.v4.ziggo.nl [83.86.89.107]) (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 27ACA20DD4; Fri, 19 Jun 2020 14:50:21 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1592578222; bh=REYmcY8cxaI9Sz3+PaxzgBVhHq/qpIHIa00Ix67ORNc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=oOVjpNgKKwxxarverJJXvTHgLgF7dOX/cdG7tr/E7lEi4pzmpKmtZ21cyW3YXEGZe QKObfRkLNKcd80krbT9U245JpYv/feupIzCOt/rJTWqwuR66c6RtxpmsWlMc+dPtE9 t8HduK2ls/zF+0IZh96UHOFWm8wMoloUzD+Y08U0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, teroincn@gmail.com, Richard Guy Briggs , Paul Moore , Sasha Levin Subject: [PATCH 4.14 100/190] audit: fix a net reference leak in audit_send_reply() Date: Fri, 19 Jun 2020 16:32:25 +0200 Message-Id: <20200619141638.582021944@linuxfoundation.org> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20200619141633.446429600@linuxfoundation.org> References: <20200619141633.446429600@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Sender: stable-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Paul Moore [ Upstream commit a48b284b403a4a073d8beb72d2bb33e54df67fb6 ] If audit_send_reply() fails when trying to create a new thread to send the reply it also fails to cleanup properly, leaking a reference to a net structure. This patch fixes the error path and makes a handful of other cleanups that came up while fixing the code. Reported-by: teroincn@gmail.com Reviewed-by: Richard Guy Briggs Signed-off-by: Paul Moore Signed-off-by: Sasha Levin --- kernel/audit.c | 50 +++++++++++++++++++++++++++++--------------------- 1 file changed, 29 insertions(+), 21 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index aa6d5e39526b..53224f399038 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -897,19 +897,30 @@ out_kfree_skb: return NULL; } +static void audit_free_reply(struct audit_reply *reply) +{ + if (!reply) + return; + + if (reply->skb) + kfree_skb(reply->skb); + if (reply->net) + put_net(reply->net); + kfree(reply); +} + static int audit_send_reply_thread(void *arg) { struct audit_reply *reply = (struct audit_reply *)arg; - struct sock *sk = audit_get_sk(reply->net); mutex_lock(&audit_cmd_mutex); mutex_unlock(&audit_cmd_mutex); /* Ignore failure. It'll only happen if the sender goes away, because our timeout is set to infinite. */ - netlink_unicast(sk, reply->skb, reply->portid, 0); - put_net(reply->net); - kfree(reply); + netlink_unicast(audit_get_sk(reply->net), reply->skb, reply->portid, 0); + reply->skb = NULL; + audit_free_reply(reply); return 0; } @@ -923,35 +934,32 @@ static int audit_send_reply_thread(void *arg) * @payload: payload data * @size: payload size * - * Allocates an skb, builds the netlink message, and sends it to the port id. - * No failure notifications. + * Allocates a skb, builds the netlink message, and sends it to the port id. */ static void audit_send_reply(struct sk_buff *request_skb, int seq, int type, int done, int multi, const void *payload, int size) { - struct net *net = sock_net(NETLINK_CB(request_skb).sk); - struct sk_buff *skb; struct task_struct *tsk; - struct audit_reply *reply = kmalloc(sizeof(struct audit_reply), - GFP_KERNEL); + struct audit_reply *reply; + reply = kzalloc(sizeof(*reply), GFP_KERNEL); if (!reply) return; - skb = audit_make_reply(seq, type, done, multi, payload, size); - if (!skb) - goto out; - - reply->net = get_net(net); + reply->skb = audit_make_reply(seq, type, done, multi, payload, size); + if (!reply->skb) + goto err; + reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk)); reply->portid = NETLINK_CB(request_skb).portid; - reply->skb = skb; tsk = kthread_run(audit_send_reply_thread, reply, "audit_send_reply"); - if (!IS_ERR(tsk)) - return; - kfree_skb(skb); -out: - kfree(reply); + if (IS_ERR(tsk)) + goto err; + + return; + +err: + audit_free_reply(reply); } /*