From 5f7da044f8bc1cfb21c962edf34bd5699a76e7ae Mon Sep 17 00:00:00 2001
From: Nicholas Bellinger <nab@linux-iscsi.org>
Date: Thu, 5 Mar 2015 03:28:24 +0000
Subject: [PATCH] target: Fix virtual LUN=0 target_configure_device failure
 OOPs

This patch fixes a NULL pointer dereference triggered by a late
target_configure_device() -> alloc_workqueue() failure that results
in target_free_device() being called with DF_CONFIGURED already set,
which subsequently OOPses in destroy_workqueue() code.

Currently this only happens at modprobe target_core_mod time when
core_dev_setup_virtual_lun0() -> target_configure_device() fails,
and the explicit target_free_device() gets called.

To address this bug originally introduced by commit 0fd97ccf45, go
ahead and move DF_CONFIGURED to end of target_configure_device()
code to handle this special failure case.

Reported-by: Claudio Fleiner <cmf@daterainc.com>
Cc: Claudio Fleiner <cmf@daterainc.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: <stable@vger.kernel.org> # v3.7+
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 drivers/target/target_core_device.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/target/target_core_device.c b/drivers/target/target_core_device.c
index 37449bdd62f682..7fc5eae875de9c 100644
--- a/drivers/target/target_core_device.c
+++ b/drivers/target/target_core_device.c
@@ -1548,8 +1548,6 @@ int target_configure_device(struct se_device *dev)
 	ret = dev->transport->configure_device(dev);
 	if (ret)
 		goto out;
-	dev->dev_flags |= DF_CONFIGURED;
-
 	/*
 	 * XXX: there is not much point to have two different values here..
 	 */
@@ -1611,6 +1609,8 @@ int target_configure_device(struct se_device *dev)
 	list_add_tail(&dev->g_dev_node, &g_device_list);
 	mutex_unlock(&g_device_mutex);
 
+	dev->dev_flags |= DF_CONFIGURED;
+
 	return 0;
 
 out_free_alua:
-- 
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