[PATCH 4.9 003/177] SMB3: Validate negotiate request must always be signed

[Greg Kroah-Hartman]

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

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

From: Steve French <smfrench@xxxxxxxxx>

commit 4587eee04e2ac7ac3ac9fa2bc164fb6e548f99cd upstream.

According to MS-SMB2 3.2.55 validate_negotiate request must
always be signed. Some Windows can fail the request if you send it unsigned

See kernel bugzilla bug 197311

CC: Stable <stable@xxxxxxxxxxxxxxx>
Acked-by: Ronnie Sahlberg <lsahlber.redhat.com>
Signed-off-by: Steve French <smfrench@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/cifs/smb2pdu.c |    3 +++
 1 file changed, 3 insertions(+)

--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -1712,6 +1712,9 @@ SMB2_ioctl(const unsigned int xid, struc
 	} else
 		iov[0].iov_len = get_rfc1002_length(req) + 4;
 
+	/* validate negotiate request must be signed - see MS-SMB2 3.2.5.5 */
+	if (opcode == FSCTL_VALIDATE_NEGOTIATE_INFO)
+		req->hdr.Flags |= SMB2_FLAGS_SIGNED;
 
 	rc = SendReceive2(xid, ses, iov, num_iovecs, &resp_buftype, 0);
 	rsp = (struct smb2_ioctl_rsp *)iov[0].iov_base;