6.15-stable review patch. If anyone has any objections, please let me know.
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From: Joe Damato jdamato@fastly.com
[ Upstream commit b4a8085ceefb7bbb12c2b71c55e71fc946c6929f ]
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 john.cs.hey@gmail.com Closes: https://lore.kernel.org/netdev/CAP=Rh=OEsn4y_2LvkO3UtDWurKcGPnZ_NPSXK=FbgygN... Signed-off-by: Joe Damato jdamato@fastly.com Acked-by: Stanislav Fomichev sdf@fomichev.me Acked-by: Jacob Keller jacob.e.keller@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 3f089c3d47b23..d8595e84326db 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);