[PATCH 6.18 054/181] NFS: Fix up the automount fs_context to use the correct cred

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

6.18-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Trond Myklebust <trond.myklebust@hammerspace.com>

[ 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>
---
 fs/nfs/namespace.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/fs/nfs/namespace.c b/fs/nfs/namespace.c
index 9e4d94f41fc67..af9be0c5f5163 100644
--- 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);
-- 
2.51.0