[PATCH 5.15.y] ksmbd: Fix refcount leak when invalid session is found on session lookup

[Li hongliang]

From: Namjae Jeon <linkinjeon@xxxxxxxxxx>

[ Upstream commit cafb57f7bdd57abba87725eb4e82bbdca4959644 ]

When a session is found but its state is not SMB2_SESSION_VALID, It
indicates that no valid session was found, but it is missing to decrement
the reference count acquired by the session lookup, which results in
a reference count leak. This patch fixes the issue by explicitly calling
ksmbd_user_session_put to release the reference to the session.

Cc: stable@xxxxxxxxxxxxxxx
Reported-by: Alexandre <roger.andersen@xxxxxxxxxxxxxx>
Reported-by: Stanislas Polu <spolu@xxxxxxx>
Signed-off-by: Namjae Jeon <linkinjeon@xxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Li hongliang <1468888505@xxxxxxx>
---
 fs/ksmbd/mgmt/user_session.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/ksmbd/mgmt/user_session.c b/fs/ksmbd/mgmt/user_session.c
index f59714bfc819..8bd18610547d 100644
--- a/fs/ksmbd/mgmt/user_session.c
+++ b/fs/ksmbd/mgmt/user_session.c
@@ -302,8 +302,10 @@ struct ksmbd_session *ksmbd_session_lookup_all(struct ksmbd_conn *conn,
 	sess = ksmbd_session_lookup(conn, id);
 	if (!sess && conn->binding)
 		sess = ksmbd_session_lookup_slowpath(id);
-	if (sess && sess->state != SMB2_SESSION_VALID)
+	if (sess && sess->state != SMB2_SESSION_VALID) {
+		ksmbd_user_session_put(sess);
 		sess = NULL;
+	}
 	return sess;
 }
 
-- 
2.34.1