vmbus: use rcu for per-cpu channel list
The per-cpu channel list is now referred to in the interrupt
routine. This is mostly safe since the host will not normally generate
an interrupt when channel is being deleted but if it did then there
would be a use after free problem.
To solve, this use RCU protection on ther per-cpu list.
Fixes: 631e63a9f346 ("vmbus: change to per channel tasklet")
Signed-off-by: Stephen Hemminger <[email protected]>
Signed-off-by: K. Y. Srinivasan <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
diff --git a/include/linux/hyperv.h b/include/linux/hyperv.h
index 62bbf3c..c4c7ae9 100644
--- a/include/linux/hyperv.h
+++ b/include/linux/hyperv.h
@@ -845,6 +845,13 @@ struct vmbus_channel {
* link up channels based on their CPU affinity.
*/
struct list_head percpu_list;
+
+ /*
+ * Defer freeing channel until after all cpu's have
+ * gone through grace period.
+ */
+ struct rcu_head rcu;
+
/*
* For performance critical channels (storage, networking
* etc,), Hyper-V has a mechanism to enhance the throughput
