Commit b54521a3 authored Mar 05, 2015 by Nicholas Bellinger Committed by Sasha Levin Mar 28, 2015

target: Fix virtual LUN=0 target_configure_device failure OOPs



[ Upstream commit 5f7da044f8bc1cfb21c962edf34bd5699a76e7ae ]

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>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>

parent 6526d32f

drivers/target/target_core_device.c

+2 −2

Original line number	Diff line number	Diff line
		@@ -1598,8 +1598,6 @@ 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..
		*/
		@@ -1661,6 +1659,8 @@ 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: