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=-18.8 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,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 C9098C433ED for ; Mon, 5 Apr 2021 08:58:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9FE1A610E8 for ; Mon, 5 Apr 2021 08:58:23 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233659AbhDEI62 (ORCPT ); Mon, 5 Apr 2021 04:58:28 -0400 Received: from mail.kernel.org ([198.145.29.99]:37544 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233340AbhDEI5v (ORCPT ); Mon, 5 Apr 2021 04:57:51 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 301B8610E8; Mon, 5 Apr 2021 08:57:44 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1617613065; bh=3SHKbbEXoPErrAsIDb2nUkQQYB67JgIL0oeUYVPoEH0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=t/34lefzYaWzQABKVu5g0Ih0n6EniawWAJbiU2XnYoLqajt8pVNLlDMog5AOCksBV uAGRV9L0PYnWkClI8aMpvPoMueyN8qc5FWMPWjQv4YXvhHJHlAlxyMbL37+FfBsfyv 5gbtiynfBzjvnEew8HpHogx7NTNw4HLcvcA0EX34= 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 , Wen Yang Subject: [PATCH 4.9 34/35] audit: fix a net reference leak in audit_send_reply() Date: Mon, 5 Apr 2021 10:54:09 +0200 Message-Id: <20210405085019.951555935@linuxfoundation.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20210405085018.871387942@linuxfoundation.org> References: <20210405085018.871387942@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: Paul Moore commit a48b284b403a4a073d8beb72d2bb33e54df67fb6 upstream. 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 Cc: # 4.9.x Signed-off-by: Wen Yang Signed-off-by: Greg Kroah-Hartman --- kernel/audit.c | 46 ++++++++++++++++++++++++++++------------------ 1 file changed, 28 insertions(+), 18 deletions(-) --- a/kernel/audit.c +++ b/kernel/audit.c @@ -580,6 +580,18 @@ 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; @@ -592,8 +604,8 @@ static int audit_send_reply_thread(void /* Ignore failure. It'll only happen if the sender goes away, because our timeout is set to infinite. */ netlink_unicast(aunet->nlsk , reply->skb, reply->portid, 0); - put_net(net); - kfree(reply); + reply->skb = NULL; + audit_free_reply(reply); return 0; } /** @@ -606,36 +618,34 @@ static int audit_send_reply_thread(void * @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) { u32 portid = NETLINK_CB(request_skb).portid; - 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(portid, seq, type, done, multi, payload, size); - if (!skb) - goto out; + reply->skb = audit_make_reply(portid, seq, type, done, multi, payload, size); + if (!reply->skb) + goto err; - reply->net = get_net(net); + reply->net = get_net(sock_net(NETLINK_CB(request_skb).sk)); reply->portid = 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); } /*