Commit 5f7da044 authored Mar 05, 2015 by Nicholas Bellinger

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 0fd97ccf, 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>

parent 215a8fe4

drivers/target/target_core_device.c

+2 −2

Original line number	Original line	Diff line number	Diff line
	@@ -1548,8 +1548,6 @@ int target_configure_device(struct se_device *dev)
	ret = dev->transport->configure_device(dev);		ret = dev->transport->configure_device(dev);
	if (ret)		if (ret)
	goto out;		goto out;
	dev->dev_flags \|= DF_CONFIGURED;

	/*		/*
	* XXX: there is not much point to have two different values here..		* 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);		list_add_tail(&dev->g_dev_node, &g_device_list);
	mutex_unlock(&g_device_mutex);		mutex_unlock(&g_device_mutex);

			dev->dev_flags \|= DF_CONFIGURED;

	return 0;		return 0;

	out_free_alua:		out_free_alua: