e1000e: add rtnl_lock() to e1000_reset_task

BugLink: https://bugs.launchpad.net/bugs/1923220
[ Upstream commit 21f857f0321d0d0ea9b1a758bd55dc63d1cb2437 ]

A possible race condition was found in e1000_reset_task,
after discovering a similar issue in igb driver via
commit 024a8168b749 ("igb: reinit_locked() should be called
with rtnl_lock").

Added rtnl_lock() and rtnl_unlock() to avoid this.

Fixes: bc7f75fa9788 ("[E1000E]: New pci-express e1000 driver (currently for ICH9 devices only)")
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Vitaly Lifshits <vitaly.lifshits@intel.com>
Tested-by: Dvora Fuxbrumer <dvorax.fuxbrumer@linux.intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index 8affa56032eb39bd0a5feb384dc254574df387f7..d30fd406b25d21666e3387c559784cd21a141956 100644 (file)
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5953,15 +5953,19 @@ static void e1000_reset_task(struct work_struct *work)
        struct e1000_adapter *adapter;
        adapter = container_of(work, struct e1000_adapter, reset_task);
 
+       rtnl_lock();
        /* don't run the task if already down */
-       if (test_bit(__E1000_DOWN, &adapter->state))
+       if (test_bit(__E1000_DOWN, &adapter->state)) {
+               rtnl_unlock();
                return;
+       }
 
        if (!(adapter->flags & FLAG_RESTART_NOW)) {
                e1000e_dump(adapter);
                e_err("Reset adapter unexpectedly\n");
        }
        e1000e_reinit_locked(adapter);
+       rtnl_unlock();
 }
 
 /**