[PATCH 4.14 33/59] e1000e: add rtnl_lock() to e1000_reset_task

Greg Kroah-Hartman
2021-03-29T08:11:02Z

From: Vitaly Lifshits <vitaly.lifshits@intel.com>

[ 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>
---
drivers/net/ethernet/intel/e1000e/netdev.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/intel/e1000e/netdev.c b/drivers/net/ethernet/intel/e1000e/netdev.c
index fff55f0bed30..f50d0da8fefe 100644
--- a/drivers/net/ethernet/intel/e1000e/netdev.c
+++ b/drivers/net/ethernet/intel/e1000e/netdev.c
@@ -5942,15 +5942,19 @@ 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();
}

/**
--
2.30.1