NFS prevent double free in async nfs4_exchange_id

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 <kolga@netapp.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Olga Kornievskaia 2017-03-13 10:36:19 -04:00 committed by Greg Kroah-Hartman
parent 87144ec250
commit b76d4fb2d9

View File

@ -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 @@ out_server_owner:
kfree(calldata->res.server_owner);
out_calldata:
kfree(calldata);
nfs_put_client(clp);
goto out;
}