[PATCH 4.8 096/140] Set previous session id correctly on SMB3 reconnect

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

4.8-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Steve French <smfrench@gmail.com>

commit c2afb8147e69819885493edf3a7c1ce03aaf2d4e upstream.

Signed-off-by: Steve French <steve.french@primarydata.com>
Reported-by: David Goebel <davidgoe@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 fs/cifs/smb2pdu.c |    5 +++++
 fs/cifs/smb2pdu.h |    2 +-
 2 files changed, 6 insertions(+), 1 deletion(-)

--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -604,6 +604,7 @@ SMB2_sess_setup(const unsigned int xid,
 	char *security_blob = NULL;
 	unsigned char *ntlmssp_blob = NULL;
 	bool use_spnego = false; /* else use raw ntlmssp */
+	u64 previous_session = ses->Suid;
 
 	cifs_dbg(FYI, "Session Setup\n");
 
@@ -641,6 +642,10 @@ ssetup_ntlmssp_authenticate:
 		return rc;
 
 	req->hdr.SessionId = 0; /* First session, not a reauthenticate */
+
+	/* if reconnect, we need to send previous sess id, otherwise it is 0 */
+	req->PreviousSessionId = previous_session;
+
 	req->Flags = 0; /* MBZ */
 	/* to enable echos and oplocks */
 	req->hdr.CreditRequest = cpu_to_le16(3);
--- a/fs/cifs/smb2pdu.h
+++ b/fs/cifs/smb2pdu.h
@@ -276,7 +276,7 @@ struct smb2_sess_setup_req {
 	__le32 Channel;
 	__le16 SecurityBufferOffset;
 	__le16 SecurityBufferLength;
-	__le64 PreviousSessionId;
+	__u64 PreviousSessionId;
 	__u8   Buffer[1];	/* variable length GSS security buffer */
 } __packed;