Return-Path: Received: from mx142.netapp.com ([216.240.21.19]:36008 "EHLO mx142.netapp.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752332AbdCMOgY (ORCPT ); Mon, 13 Mar 2017 10:36:24 -0400 From: Olga Kornievskaia To: , CC: Subject: [PATCH v2 1/1] NFS prevent double free in async nfs4_exchange_id Date: Mon, 13 Mar 2017 10:36:19 -0400 Message-ID: <20170313143619.39590-1-kolga@netapp.com> In-Reply-To: <1489247359.3260.7.camel@primarydata.com> References: <1489247359.3260.7.camel@primarydata.com> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-nfs-owner@vger.kernel.org List-ID: 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 --- fs/nfs/nfs4proc.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c index 59be0f7..1a65af2 100644 --- a/fs/nfs/nfs4proc.c +++ b/fs/nfs/nfs4proc.c @@ -7426,11 +7426,11 @@ static void nfs4_exchange_id_release(void *data) 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 nfs_client *clp, struct rpc_cred *cred, 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 @@ static int _nfs4_proc_exchange_id(struct nfs_client *clp, struct rpc_cred *cred, kfree(calldata->res.server_owner); out_calldata: kfree(calldata); + nfs_put_client(clp); goto out; } -- 1.8.3.1