RDMA/nes: Free IRQ before killing tasklet

Move the free_irq() call in nes_remove() to before the tasklet_kill();
otherwise there is a window after tasklet_kill() where a new interrupt
can be handled and reschedule the tasklet, leading to a use-after-free
crash.

Cc: <stable@kernel.org>
Signed-off-by: Roland Dreier <rolandd@cisco.com>
diff --git a/drivers/infiniband/hw/nes/nes.c b/drivers/infiniband/hw/nes/nes.c
index 7a89cd7..b00b0e3 100644
--- a/drivers/infiniband/hw/nes/nes.c
+++ b/drivers/infiniband/hw/nes/nes.c
@@ -744,13 +744,13 @@
 
 	list_del(&nesdev->list);
 	nes_destroy_cqp(nesdev);
+
+	free_irq(pcidev->irq, nesdev);
 	tasklet_kill(&nesdev->dpc_tasklet);
 
 	/* Deallocate the Adapter Structure */
 	nes_destroy_adapter(nesdev->nesadapter);
 
-	free_irq(pcidev->irq, nesdev);
-
 	if (nesdev->msi_enabled) {
 		pci_disable_msi(pcidev);
 	}