[SCSI] stex: fix scan of nonexistent lun

During a manual scan, a user can send command to a nonexistent
lun, precisely at the point of max_lun. Normally it's possible
(but not required) that the firmware has the knowledge that it
is an invalid lun. In the particular case when max_lun is 256,
however, the nonexistent lun 256 will be confused with lun 0,
because the lun member in a request message is only u8, and 256
will become 0. So we need to fix the problem, at least, at the
driver level.

Signed-off-by: Ed Lin <ed.lin@promise.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>

1 files changed, 5 insertions, 0 deletions

diff --git a/drivers/scsi/stex.c b/drivers/scsi/stex.c
index 3058bb1aff95..fd7b15be7640 100644
--- a/drivers/scsi/stex.c
+++ b/drivers/scsi/stex.c
@@ -623,6 +623,11 @@ stex_queuecommand(struct scsi_cmnd *cmd, void (* done)(struct scsi_cmnd *))
                 }
                 break;
         case INQUIRY:
+                if (lun >= host->max_lun) {
+                        cmd->result = DID_NO_CONNECT << 16;
+                        done(cmd);
+                        return 0;
+                }
                 if (id != host->max_id - 1)
                         break;
                 if (!lun && !cmd->device->channel &&