[PATCH] scsi: storvsc: Set correct data length for sending SCSI command without payload

[longli@linuxonhyperv.com]

From: Long Li <longli@microsoft.com>

In StorVSC, payload->range.len is used to indicate if this SCSI command
carries payload. This data is allocated as part of the private driver
data by the upper layer and may get passed to lower driver uninitialized.

If a SCSI command doesn't carry payload, the driver may use this value as
is for communicating with host, resulting in possible corruption.

Fix this by always initializing this value.

Fixes: be0cf6ca301c ("scsi: storvsc: Set the tablesize based on the information given by the host")
Cc: stable@kernel.org
Signed-off-by: Long Li <longli@microsoft.com>
---
 drivers/scsi/storvsc_drv.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/scsi/storvsc_drv.c b/drivers/scsi/storvsc_drv.c
index 7ceb982040a5..ca5e5c0aeabf 100644
--- a/drivers/scsi/storvsc_drv.c
+++ b/drivers/scsi/storvsc_drv.c
@@ -1789,6 +1789,7 @@ static int storvsc_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *scmnd)
 
 	length = scsi_bufflen(scmnd);
 	payload = (struct vmbus_packet_mpb_array *)&cmd_request->mpb;
+	payload->range.len = 0;
 	payload_sz = 0;
 
 	if (scsi_sg_count(scmnd)) {
-- 
2.43.0