target: NULL dereference on error path

During a failure in transport_add_device_to_core_hba() code, we called
destroy_workqueue(dev->tmr_wq) before ->tmr_wq was allocated which leads
to an oops.

This fixes a regression introduced in with:

commit af8772926f019b7bddd7477b8de5f3b0f12bad21
Author: Christoph Hellwig <hch@infradead.org>
Date:   Sun Jul 8 15:58:49 2012 -0400

    target: replace the processing thread with a TMR work queue

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

diff --git a/drivers/target/target_core_transport.c b/drivers/target/target_core_transport.c
index 7647ecafbcc7ba5425eccb9cab1be3fdc4d50f31..0eaae23d12b576547fa51f25ed8f05579f6ec646 100644 (file)
--- a/drivers/target/target_core_transport.c
+++ b/drivers/target/target_core_transport.c
@@ -1098,7 +1098,7 @@ struct se_device *transport_add_device_to_core_hba(
         * Setup the Asymmetric Logical Unit Assignment for struct se_device
         */
        if (core_setup_alua(dev, force_pt) < 0)
-               goto out;
+               goto err_dev_list;
 
        /*
         * Startup the struct se_device processing thread
@@ -1108,7 +1108,7 @@ struct se_device *transport_add_device_to_core_hba(
        if (!dev->tmr_wq) {
                pr_err("Unable to create tmr workqueue for %s\n",
                        dev->transport->name);
-               goto out;
+               goto err_dev_list;
        }
        /*
         * Setup work_queue for QUEUE_FULL
@@ -1126,7 +1126,7 @@ struct se_device *transport_add_device_to_core_hba(
                if (!inquiry_prod || !inquiry_rev) {
                        pr_err("All non TCM/pSCSI plugins require"
                                " INQUIRY consts\n");
-                       goto out;
+                       goto err_wq;
                }
 
                strncpy(&dev->se_sub_dev->t10_wwn.vendor[0], "LIO-ORG", 8);
@@ -1136,9 +1136,10 @@ struct se_device *transport_add_device_to_core_hba(
        scsi_dump_inquiry(dev);
 
        return dev;
-out:
-       destroy_workqueue(dev->tmr_wq);
 
+err_wq:
+       destroy_workqueue(dev->tmr_wq);
+err_dev_list:
        spin_lock(&hba->device_lock);
        list_del(&dev->dev_list);
        hba->dev_count--;