[PATCH 5.6 065/161] smb3: add indatalen that can be a non-zero value to calculation of credit charge in smb2 ioctl

[Greg Kroah-Hartman]

From: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>

commit ebf57440ec59a36e1fc5fe91e31d66ae0d1662d0 upstream.

Some of tests in xfstests failed with cifsd kernel server since commit
e80ddeb2f70e. cifsd kernel server validates credit charge from client
by calculating it base on max((InputCount + OutputCount) and
(MaxInputResponse + MaxOutputResponse)) according to specification.

MS-SMB2 specification describe credit charge calculation of smb2 ioctl :

If Connection.SupportsMultiCredit is TRUE, the server MUST validate
CreditCharge based on the maximum of (InputCount + OutputCount) and
(MaxInputResponse + MaxOutputResponse), as specified in section 3.3.5.2.5.
If the validation fails, it MUST fail the IOCTL request with
STATUS_INVALID_PARAMETER.

This patch add indatalen that can be a non-zero value to calculation of
credit charge in SMB2_ioctl_init().

Fixes: e80ddeb2f70e ("smb3: fix incorrect number of credits when ioctl
MaxOutputResponse > 64K")
Cc: Stable <stable@xxxxxxxxxxxxxxx>
Reviewed-by: Aurelien Aptel <aaptel@xxxxxxxx>
Cc: Steve French <smfrench@xxxxxxxxx>
Signed-off-by: Namjae Jeon <namjae.jeon@xxxxxxxxxxx>
Signed-off-by: Steve French <stfrench@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 fs/cifs/smb2pdu.c |    4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

--- a/fs/cifs/smb2pdu.c
+++ b/fs/cifs/smb2pdu.c
@@ -2868,7 +2868,9 @@ SMB2_ioctl_init(struct cifs_tcon *tcon,
 	 * 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));
+	req->sync_hdr.CreditCharge =
+		cpu_to_le16(DIV_ROUND_UP(max(indatalen, max_response_size),
+					 SMB2_MAX_BUFFER_SIZE));
 	if (is_fsctl)
 		req->Flags = cpu_to_le32(SMB2_0_IOCTL_IS_FSCTL);
 	else