From: Namjae Jeon <linkinjeon@kernel.org>
Date: Tue, 2 May 2023 23:43:30 +0000 (+0900)
Subject: ksmbd: block asynchronous requests when making a delay on session setup
X-Git-Tag: v6.1.29~25
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=502cf9709036d9305495876fa8c33c8a52541b15;p=users%2Fdwmw2%2Flinux.git

ksmbd: block asynchronous requests when making a delay on session setup

[ Upstream commit b096d97f47326b1e2dbdef1c91fab69ffda54d17 ]

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: Sasha Levin <sashal@kernel.org>
---

diff --git a/fs/ksmbd/smb2pdu.c b/fs/ksmbd/smb2pdu.c
index d3f33194faf1a..e7594a56cbfe3 100644
--- a/fs/ksmbd/smb2pdu.c
+++ b/fs/ksmbd/smb2pdu.c
@@ -1862,8 +1862,11 @@ out_err:
 
 			sess->last_active = jiffies;
 			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);
+			}
 		}
 	}