From: Ivan Vecera ivecera@redhat.com
[ Upstream commit aa626da947e9cd30c4cf727493903e1adbb2c0a0 ]
iavf_reset_task() takes crit_lock at the beginning and holds it during whole call. The function subsequently calls iavf_init_interrupt_scheme() that grabs RTNL. Problem occurs when userspace initiates during the reset task any ndo callback that runs under RTNL like iavf_open() because some of that functions tries to take crit_lock. This leads to classic A-B B-A deadlock scenario.
To resolve this situation the device should be detached in iavf_reset_task() prior taking crit_lock to avoid subsequent ndos running under RTNL and reattach the device at the end.
Fixes: 62fe2a865e6d ("i40evf: add missing rtnl_lock() around i40evf_set_interrupt_capability") Cc: Jacob Keller jacob.e.keller@intel.com Cc: Patryk Piotrowski patryk.piotrowski@intel.com Cc: SlawomirX Laba slawomirx.laba@intel.com Tested-by: Vitaly Grinberg vgrinber@redhat.com Signed-off-by: Ivan Vecera ivecera@redhat.com Tested-by: Konrad Jankowski konrad0.jankowski@intel.com Signed-off-by: Tony Nguyen anthony.l.nguyen@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/net/ethernet/intel/iavf/iavf_main.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-)
diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c index db95786c3419f..00b2ef01f4ea6 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -2222,6 +2222,11 @@ static void iavf_reset_task(struct work_struct *work) int i = 0, err; bool running;
+ /* Detach interface to avoid subsequent NDO callbacks */ + rtnl_lock(); + netif_device_detach(netdev); + rtnl_unlock(); + /* When device is being removed it doesn't make sense to run the reset * task, just return in such a case. */ @@ -2229,7 +2234,7 @@ static void iavf_reset_task(struct work_struct *work) if (adapter->state != __IAVF_REMOVE) queue_work(iavf_wq, &adapter->reset_task);
- return; + goto reset_finish; }
while (!mutex_trylock(&adapter->client_lock)) @@ -2299,7 +2304,6 @@ static void iavf_reset_task(struct work_struct *work)
if (running) { netif_carrier_off(netdev); - netif_tx_stop_all_queues(netdev); adapter->link_up = false; iavf_napi_disable_all(adapter); } @@ -2412,7 +2416,7 @@ static void iavf_reset_task(struct work_struct *work) mutex_unlock(&adapter->client_lock); mutex_unlock(&adapter->crit_lock);
- return; + goto reset_finish; reset_err: if (running) { set_bit(__IAVF_VSI_DOWN, adapter->vsi.state); @@ -2423,6 +2427,10 @@ static void iavf_reset_task(struct work_struct *work) mutex_unlock(&adapter->client_lock); mutex_unlock(&adapter->crit_lock); dev_err(&adapter->pdev->dev, "failed to allocate resources during reinit\n"); +reset_finish: + rtnl_lock(); + netif_device_attach(netdev); + rtnl_unlock(); }
/**