ksmbd: fix use-after-free in ksmbd_sessions_deregister()

In multichannel mode, UAF issue can occur in session_deregister
when the second channel sets up a session through the connection of
the first channel. session that is freed through the global session
table can be accessed again through ->sessions of connection.

Cc: stable@vger.kernel.org
Reported-by: Norbert Szetei <norbert@doyensec.com>
Tested-by: Norbert Szetei <norbert@doyensec.com>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
This commit is contained in:
Namjae Jeon 2025-03-22 09:20:19 +09:00 committed by Steve French
parent 6955bfef8f
commit 15a9605f8d

View File

@ -230,6 +230,9 @@ void ksmbd_sessions_deregister(struct ksmbd_conn *conn)
if (!ksmbd_chann_del(conn, sess) &&
xa_empty(&sess->ksmbd_chann_list)) {
hash_del(&sess->hlist);
down_write(&conn->session_lock);
xa_erase(&conn->sessions, sess->id);
up_write(&conn->session_lock);
ksmbd_session_destroy(sess);
}
}