From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Wed, 16 Sep 2015 06:07:45 +0000 (-0700)
Subject: target: Fix target_sense_desc_format NULL pointer dereference
X-Git-Tag: firefly_0821_release~176^2~1002^2~2
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=f3bb467ff64b2598d023b3a07592748fa7768b6a;p=firefly-linux-kernel-4.4.55.git

target: Fix target_sense_desc_format NULL pointer dereference

This patch allows target_sense_desc_format() to be called without a
valid se_device pointer, which can occur during an early exception
ahead of transport_lookup_cmd_lun() setting up se_cmd->se_device.

This addresses a v4.3-rc1 specific NULL pointer dereference
regression introduced by commit 4e4937e8.

Cc: Sagi Grimberg <sagig@mellanox.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---

diff --git a/drivers/target/target_core_hba.c b/drivers/target/target_core_hba.c
index 9522960c7fdd..22390e0e046c 100644
--- a/drivers/target/target_core_hba.c
+++ b/drivers/target/target_core_hba.c
@@ -187,5 +187,5 @@ core_delete_hba(struct se_hba *hba)
 
 bool target_sense_desc_format(struct se_device *dev)
 {
-	return dev->transport->get_blocks(dev) > U32_MAX;
+	return (dev) ? dev->transport->get_blocks(dev) > U32_MAX : false;
 }