From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:35142 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754394AbdCXSBw (ORCPT ); Fri, 24 Mar 2017 14:01:52 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Olga Kornievskaia , Anna Schumaker Subject: [PATCH 4.9 11/24] NFS prevent double free in async nfs4_exchange_id Date: Fri, 24 Mar 2017 18:58:44 +0100 Message-Id: <20170324151225.962642712@linuxfoundation.org> In-Reply-To: <20170324151225.378075203@linuxfoundation.org> References: <20170324151225.378075203@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: stable-owner@vger.kernel.org List-ID: 4.9-stable review patch. If anyone has any objections, please let me know. ------------------ From: Olga Kornievskaia commit 63513232f8cd219dcaa5eafae028740ed3067d83 upstream. Since rpc_task is async, the release function should be called which will free the impl_id, scope, and owner. Trond pointed at 2 more problems: -- use of client pointer after free in the nfs4_exchangeid_release() function -- cl_count mismatch if rpc_run_task() isn't run Fixes: 8d89bd70bc9 ("NFS setup async exchange_id") Signed-off-by: Olga Kornievskaia Signed-off-by: Anna Schumaker Signed-off-by: Greg Kroah-Hartman --- fs/nfs/nfs4proc.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7426,11 +7426,11 @@ static void nfs4_exchange_id_release(voi struct nfs41_exchange_id_data *cdata = (struct nfs41_exchange_id_data *)data; - nfs_put_client(cdata->args.client); if (cdata->xprt) { xprt_put(cdata->xprt); rpc_clnt_xprt_switch_put(cdata->args.client->cl_rpcclient); } + nfs_put_client(cdata->args.client); kfree(cdata->res.impl_id); kfree(cdata->res.server_scope); kfree(cdata->res.server_owner); @@ -7537,10 +7537,8 @@ static int _nfs4_proc_exchange_id(struct task_setup_data.callback_data = calldata; task = rpc_run_task(&task_setup_data); - if (IS_ERR(task)) { - status = PTR_ERR(task); - goto out_impl_id; - } + if (IS_ERR(task)) + return PTR_ERR(task); if (!xprt) { status = rpc_wait_for_completion_task(task); @@ -7568,6 +7566,7 @@ out_server_owner: kfree(calldata->res.server_owner); out_calldata: kfree(calldata); + nfs_put_client(clp); goto out; }