From d98ec3befaf256fc58247ebdcfabb8b75cead368 Mon Sep 17 00:00:00 2001
From: Steve French <stfrench@microsoft.com>
Date: Wed, 3 Jun 2020 01:33:58 -0500
Subject: [PATCH] smb3: fix incorrect number of credits when ioctl
 MaxOutputResponse > 64K

commit e80ddeb2f70ebd0786aa7cdba3e58bc931fa0bb5 upstream.

We were not checking to see if ioctl requests asked for more than
64K (ie when CIFSMaxBufSize was > 64K) so when setting larger
CIFSMaxBufSize then ioctls would fail with invalid parameter errors.
When requests ask for more than 64K in MaxOutputResponse then we
need to ask for more than 1 credit.

Signed-off-by: Steve French <stfrench@microsoft.com>
CC: Stable <stable@vger.kernel.org>
Reviewed-by: Aurelien Aptel <aaptel@suse.com>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>

diff --git a/fs/cifs/smb2pdu.c b/fs/cifs/smb2pdu.c
index b5a0207dc14e..6e93e8eebc69 100644
--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2633,7 +2633,7 @@ SMB2_ioctl_init(struct cifs_tcon *tcon, struct smb_rqst *rqst,
 	 * response size smaller.
 	 */
 	req->MaxOutputResponse = cpu_to_le32(max_response_size);
-
+	req->sync_hdr.CreditCharge = cpu_to_le16(DIV_ROUND_UP(max_response_size, SMB2_MAX_BUFFER_SIZE));
 	if (is_fsctl)
 		req->Flags = cpu_to_le32(SMB2_0_IOCTL_IS_FSCTL);
 	else
-- 
2.27.0