From 5fbf1d56c24018772e900a40a0955175ff82f35c Mon Sep 17 00:00:00 2001
From: Kevin Wolf <kwolf@redhat.com>
Date: Thu, 23 Jan 2020 18:00:54 +0100
Subject: [PATCH] iscsi: Don't access non-existent scsi_lba_status_descriptor
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In iscsi_co_block_status(), we may have received num_descriptors == 0
from the iscsi server. Therefore, we can't unconditionally access
lbas->descriptors[0]. Add the missing check.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Felipe Franciosi <felipe@nutanix.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: John Snow <jsnow@redhat.com>
Reviewed-by: Peter Lieven <pl@kamp.de>
---
 block/iscsi.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/block/iscsi.c b/block/iscsi.c
index cbd57294ab..c8feaa2f0e 100644
--- a/block/iscsi.c
+++ b/block/iscsi.c
@@ -753,7 +753,7 @@ retry:
     }
 
     lbas = scsi_datain_unmarshall(iTask.task);
-    if (lbas == NULL) {
+    if (lbas == NULL || lbas->num_descriptors == 0) {
         ret = -EIO;
         goto out_unlock;
     }