lockd: use rpc client's cl_nodename for id encoding

Taking hostname from uts namespace if not safe, because this cuold be
performind during umount operation on child reaper death. And in this case
current->nsproxy is NULL already.

Signed-off-by: Stanislav Kinsbursky <skinsbursky@parallels.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 3 insertions, 1 deletions

diff --git a/fs/lockd/mon.c b/fs/lockd/mon.c
index 38f240e104ce..e0bc36e74ceb 100644
--- a/fs/lockd/mon.c
+++ b/fs/lockd/mon.c
@@ -42,6 +42,7 @@ struct nsm_args {
         u32                     proc;
 
         char                    *mon_name;
+        char                    *nodename;
 };
 
 struct nsm_res {
@@ -141,6 +142,7 @@ static int nsm_mon_unmon(struct nsm_handle *nsm, u32 proc, struct nsm_res *res,
                 .vers           = 3,
                 .proc           = NLMPROC_NSM_NOTIFY,
                 .mon_name       = nsm->sm_mon_name,
+                .nodename       = utsname()->nodename,
         };
         struct rpc_message msg = {
                 .rpc_argp       = &args,
@@ -477,7 +479,7 @@ static void encode_my_id(struct xdr_stream *xdr, const struct nsm_args *argp)
 {
         __be32 *p;
 
-        encode_nsm_string(xdr, utsname()->nodename);
+        encode_nsm_string(xdr, argp->nodename);
         p = xdr_reserve_space(xdr, 4 + 4 + 4);
         *p++ = cpu_to_be32(argp->prog);
         *p++ = cpu_to_be32(argp->vers);