From b4a8085ceefb7bbb12c2b71c55e71fc946c6929f Mon Sep 17 00:00:00 2001 From: Joe Damato Date: Tue, 3 Jun 2025 16:34:01 +0000 Subject: [PATCH] e1000: Move cancel_work_sync to avoid deadlock Previously, e1000_down called cancel_work_sync for the e1000 reset task (via e1000_down_and_stop), which takes RTNL. As reported by users and syzbot, a deadlock is possible in the following scenario: CPU 0: - RTNL is held - e1000_close - e1000_down - cancel_work_sync (cancel / wait for e1000_reset_task()) CPU 1: - process_one_work - e1000_reset_task - take RTNL To remedy this, avoid calling cancel_work_sync from e1000_down (e1000_reset_task does nothing if the device is down anyway). Instead, call cancel_work_sync for e1000_reset_task when the device is being removed. Fixes: e400c7444d84 ("e1000: Hold RTNL when e1000_down can be called") Reported-by: syzbot+846bb38dc67fe62cc733@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/683837bf.a00a0220.52848.0003.GAE@google.com/ Reported-by: John Closes: https://lore.kernel.org/netdev/CAP=Rh=OEsn4y_2LvkO3UtDWurKcGPnZ_NPSXK=FbgygNXL37Sw@mail.gmail.com/ Signed-off-by: Joe Damato Acked-by: Stanislav Fomichev Acked-by: Jacob Keller Signed-off-by: Tony Nguyen --- drivers/net/ethernet/intel/e1000/e1000_main.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/net/ethernet/intel/e1000/e1000_main.c b/drivers/net/ethernet/intel/e1000/e1000_main.c index 3f089c3d47b2..d8595e84326d 100644 --- a/drivers/net/ethernet/intel/e1000/e1000_main.c +++ b/drivers/net/ethernet/intel/e1000/e1000_main.c @@ -477,10 +477,6 @@ static void e1000_down_and_stop(struct e1000_adapter *adapter) cancel_delayed_work_sync(&adapter->phy_info_task); cancel_delayed_work_sync(&adapter->fifo_stall_task); - - /* Only kill reset task if adapter is not resetting */ - if (!test_bit(__E1000_RESETTING, &adapter->flags)) - cancel_work_sync(&adapter->reset_task); } void e1000_down(struct e1000_adapter *adapter) @@ -1266,6 +1262,10 @@ static void e1000_remove(struct pci_dev *pdev) unregister_netdev(netdev); + /* Only kill reset task if adapter is not resetting */ + if (!test_bit(__E1000_RESETTING, &adapter->flags)) + cancel_work_sync(&adapter->reset_task); + e1000_phy_hw_reset(hw); kfree(adapter->tx_ring); -- 2.39.5