[PATCH 6.18.y 6/7] smb/server: fix minimum SMB2 PDU size

[Sasha Levin <sashal@kernel.org>]

From: ChenXiaoSong <chenxiaosong@kylinos.cn>

[ Upstream commit 4c7d8eb9a79ae5400eac19c4f6f0815bff674452 ]

The minimum SMB2 PDU size should be updated to the size of
`struct smb2_pdu` (that is, the size of `struct smb2_hdr` + 2).

Suggested-by: David Howells <dhowells@redhat.com>
Suggested-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: ChenXiaoSong <chenxiaosong@kylinos.cn>
Reviewed-by: David Howells <dhowells@redhat.com>
Acked-by: Namjae Jeon <linkinjeon@kernel.org>
Signed-off-by: Steve French <stfrench@microsoft.com>
Stable-dep-of: cfc0b8e5080a ("ksmbd: validate minimum PDU size for transform requests")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/smb/server/connection.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/smb/server/connection.c b/fs/smb/server/connection.c
index 0c583a7aaf1e2..a50213e4307e1 100644
--- a/fs/smb/server/connection.c
+++ b/fs/smb/server/connection.c
@@ -378,7 +378,7 @@ bool ksmbd_conn_alive(struct ksmbd_conn *conn)
 
 /* "+2" for BCC field (ByteCount, 2 bytes) */
 #define SMB1_MIN_SUPPORTED_PDU_SIZE (sizeof(struct smb_hdr) + 2)
-#define SMB2_MIN_SUPPORTED_HEADER_SIZE (sizeof(struct smb2_hdr) + 4)
+#define SMB2_MIN_SUPPORTED_PDU_SIZE (sizeof(struct smb2_pdu))
 
 /**
  * ksmbd_conn_handler_loop() - session thread to listen on new smb requests
@@ -478,7 +478,7 @@ int ksmbd_conn_handler_loop(void *p)
 
 		if (((struct smb2_hdr *)smb_get_msg(conn->request_buf))->ProtocolId ==
 		    SMB2_PROTO_NUMBER) {
-			if (pdu_size < SMB2_MIN_SUPPORTED_HEADER_SIZE)
+			if (pdu_size < SMB2_MIN_SUPPORTED_PDU_SIZE)
 				break;
 		}
 
-- 
2.53.0