IB/iser: Fix list iteration bug

The iteration through the list of "iser_device"s during device
lookup/creation is broken -- it might result in an infinite loop if
more than one HCA is used with iSER.  Fix this by using
list_for_each_entry() instead of the open-coded flawed list iteration
code.

Signed-off-by: Arne Redlich <arne.redlich@xiranet.com>
Signed-off-by: Erez Zilber <erezz@voltaire.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 16 insertions, 20 deletions

diff --git a/drivers/infiniband/ulp/iser/iser_verbs.c b/drivers/infiniband/ulp/iser/iser_verbs.c
index 714b8db02b29..768ba69f2fd9 100644
--- a/drivers/infiniband/ulp/iser/iser_verbs.c
+++ b/drivers/infiniband/ulp/iser/iser_verbs.c
@@ -237,33 +237,29 @@ static int iser_free_ib_conn_res(struct iser_conn *ib_conn)
 static
 struct iser_device *iser_device_find_by_ib_device(struct rdma_cm_id *cma_id)
 {
-        struct list_head    *p_list;
-        struct iser_device  *device = NULL;
+        struct iser_device *device;
 
         mutex_lock(&ig.device_list_mutex);
 
-        p_list = ig.device_list.next;
-        while (p_list != &ig.device_list) {
-                device = list_entry(p_list, struct iser_device, ig_list);
+        list_for_each_entry(device, &ig.device_list, ig_list)
                 /* find if there's a match using the node GUID */
                 if (device->ib_device->node_guid == cma_id->device->node_guid)
-                        break;
-        }
-
-        if (device == NULL) {
-                device = kzalloc(sizeof *device, GFP_KERNEL);
-                if (device == NULL)
                         goto out;
-                /* assign this device to the device */
-                device->ib_device = cma_id->device;
-                /* init the device and link it into ig device list */
-                if (iser_create_device_ib_res(device)) {
-                        kfree(device);
-                        device = NULL;
-                        goto out;
-                }
-                list_add(&device->ig_list, &ig.device_list);
+
+        device = kzalloc(sizeof *device, GFP_KERNEL);
+        if (device == NULL)
+                goto out;
+
+        /* assign this device to the device */
+        device->ib_device = cma_id->device;
+        /* init the device and link it into ig device list */
+        if (iser_create_device_ib_res(device)) {
+                kfree(device);
+                device = NULL;
+                goto out;
         }
+        list_add(&device->ig_list, &ig.device_list);
+
 out:
         BUG_ON(device == NULL);
         device->refcount++;