[PATCH] net: hinic3: unregister event callback on remove

[Guangshuo Li <lgs201920130244@gmail.com>]

hinic3_nic_probe() registers the NIC event callback with
hinic3_adev_event_register(). All probe failure paths unregister the
callback before returning.

The normal removal path, however, tears down and frees the NIC device
without calling hinic3_adev_event_unregister(), leaving the auxiliary
device event callback pointing to hinic3_nic_event().

If an event is delivered after the NIC private data has been released,
the callback may dereference the freed nic_dev and netdev objects.

Unregister the NIC event callback before starting the device teardown.

This issue was found by manual code inspection.

Fixes: 17fcb3dc12bb ("hinic3: module initialization and tx/rx logic")
Cc: stable@vger.kernel.org
Signed-off-by: Guangshuo Li <lgs201920130244@gmail.com>
---
 drivers/net/ethernet/huawei/hinic3/hinic3_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/net/ethernet/huawei/hinic3/hinic3_main.c b/drivers/net/ethernet/huawei/hinic3/hinic3_main.c
index 0a888fe4c975..42e2ad179a9f 100644
--- a/drivers/net/ethernet/huawei/hinic3/hinic3_main.c
+++ b/drivers/net/ethernet/huawei/hinic3/hinic3_main.c
@@ -499,6 +499,8 @@ static void hinic3_nic_remove(struct auxiliary_device *adev)
 	if (!hinic3_support_nic(nic_dev->hwdev))
 		return;
 
+	hinic3_adev_event_unregister(adev);
+
 	netdev = nic_dev->netdev;
 	unregister_netdev(netdev);
 
-- 
2.43.0