irdma: free iwdev->rf after removing MSI-X

Currently iwdev->rf is allocated in irdma_probe(), but free in
irdma_ib_dealloc_device(). It can be misleading. Move the free to
irdma_remove() to be more obvious.

Freeing in irdma_ib_dealloc_device() leads to KASAN use-after-free
issue. Which can also lead to NULL pointer dereference. Fix this.

irdma_deinit_interrupts() can't be moved before freeing iwdef->rf,
because in this case deinit interrupts will be done before freeing irqs.
The simplest solution is to move kfree(iwdev->rf) to irdma_remove().

Reproducer:
  sudo rmmod irdma

Minified splat(s):
  BUG: KASAN: use-after-free in irdma_remove+0x257/0x2d0 [irdma]
  Call Trace:
   <TASK>
   ? __pfx__raw_spin_lock_irqsave+0x10/0x10
   ? kfree+0x253/0x450
   ? irdma_remove+0x257/0x2d0 [irdma]
   kasan_report+0xed/0x120
   ? irdma_remove+0x257/0x2d0 [irdma]
   irdma_remove+0x257/0x2d0 [irdma]
   auxiliary_bus_remove+0x56/0x80
   device_release_driver_internal+0x371/0x530
   ? kernfs_put.part.0+0x147/0x310
   driver_detach+0xbf/0x180
   bus_remove_driver+0x11b/0x2a0
   auxiliary_driver_unregister+0x1a/0x50
   irdma_exit_module+0x40/0x4c [irdma]

  Oops: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN NOPTI
  KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007]
  RIP: 0010:ice_free_rdma_qvector+0x2a/0xa0 [ice]
  Call Trace:
   ? ice_free_rdma_qvector+0x2a/0xa0 [ice]
   irdma_remove+0x179/0x2d0 [irdma]
   auxiliary_bus_remove+0x56/0x80
   device_release_driver_internal+0x371/0x530
   ? kobject_put+0x61/0x4b0
   driver_detach+0xbf/0x180
   bus_remove_driver+0x11b/0x2a0
   auxiliary_driver_unregister+0x1a/0x50
   irdma_exit_module+0x40/0x4c [irdma]

Reported-by: Marcin Szycik <[email protected]>
Closes: https://lore.kernel.org/netdev/[email protected]/
Fixes: 3e0d3cb ("ice, irdma: move interrupts code to irdma")
Reviewed-by: Marcin Szycik <[email protected]>
Signed-off-by: Michal Swiatkowski <[email protected]>
Signed-off-by: Tatyana Nikolova <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Leon Romanovsky <[email protected]>

Author: Michal Swiatkowski

drivers/infiniband/hw/irdma/main.c

@@ -255,6 +255,8 @@ static void irdma_remove(struct auxiliary_device *aux_dev)
 	ice_rdma_update_vsi_filter(pf, iwdev->vsi_num, false);
 	irdma_deinit_interrupts(iwdev->rf, pf);
 
+	kfree(iwdev->rf);
+
 	pr_debug("INIT: Gen2 PF[%d] device remove success\n", PCI_FUNC(pf->pdev->devfn));
 }
 

drivers/infiniband/hw/irdma/verbs.c

@@ -4871,5 +4871,4 @@ void irdma_ib_dealloc_device(struct ib_device *ibdev)
 
 	irdma_rt_deinit_hw(iwdev);
 	irdma_ctrl_deinit_hw(iwdev->rf);
-	kfree(iwdev->rf);
 }