NFS: Fix up the automount fs_context to use the correct cred

[ Upstream commit a2a8fc27dd668e7562b5326b5ed2f1604cb1e2e9 ]

When automounting, the fs_context should be fixed up to use the cred
from the parent filesystem, since the operation is just extending the
namespace. Authorisation to enter that namespace will already have been
provided by the preceding lookup.

Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index d205598cdc45770af66c25606a264214dbe1871c..fc9f7b9cbf53b5e3c037d4c1f1c8769026f2feff 100644 (file)
--- a/fs/nfs/namespace.c
+++ b/fs/nfs/namespace.c
@@ -170,6 +170,11 @@ struct vfsmount *nfs_d_automount(struct path *path)
        if (!ctx->clone_data.fattr)
                goto out_fc;
 
+       if (fc->cred != server->cred) {
+               put_cred(fc->cred);
+               fc->cred = get_cred(server->cred);
+       }
+
        if (fc->net_ns != client->cl_net) {
                put_net(fc->net_ns);
                fc->net_ns = get_net(client->cl_net);