From: Taehee Yoo <ap420073@gmail.com>
Date: Thu, 8 Aug 2019 16:37:56 +0000 (-0700)
Subject: ixgbe: fix possible deadlock in ixgbe_service_task()
X-Git-Tag: v5.2.14~61
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=936315c0c94e2659ad48899e11da83c33f58bfe0;p=users%2Fdwmw2%2Flinux.git

ixgbe: fix possible deadlock in ixgbe_service_task()

[ Upstream commit 8b6381600d59871fbe44d36522272f961ab42410 ]

ixgbe_service_task() calls unregister_netdev() under rtnl_lock().
But unregister_netdev() internally calls rtnl_lock().
So deadlock would occur.

Fixes: 59dd45d550c5 ("ixgbe: firmware recovery mode")
Signed-off-by: Taehee Yoo <ap420073@gmail.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 57fd9ee6de665..f7c049559c1a5 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -7893,11 +7893,8 @@ static void ixgbe_service_task(struct work_struct *work)
 		return;
 	}
 	if (ixgbe_check_fw_error(adapter)) {
-		if (!test_bit(__IXGBE_DOWN, &adapter->state)) {
-			rtnl_lock();
+		if (!test_bit(__IXGBE_DOWN, &adapter->state))
 			unregister_netdev(adapter->netdev);
-			rtnl_unlock();
-		}
 		ixgbe_service_event_complete(adapter);
 		return;
 	}