From: Namjae Jeon <linkinjeon@kernel.org>
Date: Wed, 3 May 2023 08:43:30 +0900
Subject: [PATCH] ksmbd: block asynchronous requests when making a delay on
 session setup
References: bsc#1012628
Patch-mainline: 6.3.2
Git-commit: b096d97f47326b1e2dbdef1c91fab69ffda54d17

commit b096d97f47326b1e2dbdef1c91fab69ffda54d17 upstream.

ksmbd make a delay of 5 seconds on session setup to avoid dictionary
attacks. But the 5 seconds delay can be bypassed by using asynchronous
requests. This patch block all requests on current connection when
making a delay on sesstion setup failure.

Cc: stable@vger.kernel.org
Reported-by: zdi-disclosures@trendmicro.com # ZDI-CAN-20482
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>
---
 fs/ksmbd/smb2pdu.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index 0ebf1ee5..982c4dff 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -1874,8 +1874,11 @@ int smb2_sess_setup(struct ksmbd_work *work)
 				try_delay = true;
 
 			sess->state = SMB2_SESSION_EXPIRED;
-			if (try_delay)
+			if (try_delay) {
+				ksmbd_conn_set_need_reconnect(conn);
 				ssleep(5);
+				ksmbd_conn_set_need_negotiate(conn);
+			}
 		}
 	}
 
-- 
2.35.3