[ 051/147] [SCSI] ibmvscsi: Fix host config length field overflow

[Ben Hutchings <ben@decadent.org.uk>]

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

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

From: Benjamin Herrenschmidt <benh@kernel.crashing.org>

commit 225c56960fcafeccc2b6304f96cd3f0dbf42a16a upstream.

The length field in the host config packet is only 16-bit long, so
passing it 0x10000 (64K which is our standard PAGE_SIZE) doesn't
work and result in an empty config from the server.

Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Acked-by: Robert Jennings <rcj@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
 drivers/scsi/ibmvscsi/ibmvscsi.c |    3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/scsi/ibmvscsi/ibmvscsi.c b/drivers/scsi/ibmvscsi/ibmvscsi.c
index a846217..ef9a54c 100644
--- a/drivers/scsi/ibmvscsi/ibmvscsi.c
+++ b/drivers/scsi/ibmvscsi/ibmvscsi.c
@@ -1851,6 +1851,9 @@ static int ibmvscsi_do_host_config(struct ibmvscsi_host_data *hostdata,
 
 	host_config = &evt_struct->iu.mad.host_config;
 
+	/* The transport length field is only 16-bit */
+	length = min(0xffff, length);
+
 	/* Set up a lun reset SRP command */
 	memset(host_config, 0x00, sizeof(*host_config));
 	host_config->common.type = VIOSRP_HOST_CONFIG_TYPE;