From: Stefan Assmann sassmann@kpanic.de
[ Upstream commit 22c8fd71d3a5e6fe584ccc2c1e8760e5baefd5aa ]
The iavf watchdog task overrides adapter->state to __IAVF_RESETTING when it detects a pending reset. Then schedules iavf_reset_task() which takes care of the reset.
The reset task is capable of handling the reset without changing adapter->state. In fact we lose the state information when the watchdog task prematurely changes the adapter state. This may lead to a crash if instead of the reset task the iavf_remove() function gets called before the reset task. In that case (if we were in state __IAVF_RUNNING previously) the iavf_remove() function triggers iavf_close() which fails to close the device because of the incorrect state information.
This may result in a crash due to pending interrupts. kernel BUG at drivers/pci/msi.c:357! [...] Call Trace: [<ffffffffbddf24dd>] pci_disable_msix+0x3d/0x50 [<ffffffffc08d2a63>] iavf_reset_interrupt_capability+0x23/0x40 [iavf] [<ffffffffc08d312a>] iavf_remove+0x10a/0x350 [iavf] [<ffffffffbddd3359>] pci_device_remove+0x39/0xc0 [<ffffffffbdeb492f>] __device_release_driver+0x7f/0xf0 [<ffffffffbdeb49c3>] device_release_driver+0x23/0x30 [<ffffffffbddcabb4>] pci_stop_bus_device+0x84/0xa0 [<ffffffffbddcacc2>] pci_stop_and_remove_bus_device+0x12/0x20 [<ffffffffbddf361f>] pci_iov_remove_virtfn+0xaf/0x160 [<ffffffffbddf3bcc>] sriov_disable+0x3c/0xf0 [<ffffffffbddf3ca3>] pci_disable_sriov+0x23/0x30 [<ffffffffc0667365>] i40e_free_vfs+0x265/0x2d0 [i40e] [<ffffffffc0667624>] i40e_pci_sriov_configure+0x144/0x1f0 [i40e] [<ffffffffbddd5307>] sriov_numvfs_store+0x177/0x1d0 Code: 00 00 e8 3c 25 e3 ff 49 c7 86 88 08 00 00 00 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 48 8b 7b 28 e8 0d 44 RIP [<ffffffffbbbf1068>] free_msi_irqs+0x188/0x190
The solution is to not touch the adapter->state in iavf_watchdog_task() and let the reset task handle the state transition.
Signed-off-by: Stefan Assmann sassmann@kpanic.de 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 | 1 - 1 file changed, 1 deletion(-)
diff --git a/drivers/net/ethernet/intel/iavf/iavf_main.c b/drivers/net/ethernet/intel/iavf/iavf_main.c index 606a01ce4073..0d0f16617dde 100644 --- a/drivers/net/ethernet/intel/iavf/iavf_main.c +++ b/drivers/net/ethernet/intel/iavf/iavf_main.c @@ -1984,7 +1984,6 @@ static void iavf_watchdog_task(struct work_struct *work) /* check for hw reset */ reg_val = rd32(hw, IAVF_VF_ARQLEN1) & IAVF_VF_ARQLEN1_ARQENABLE_MASK; if (!reg_val) { - adapter->state = __IAVF_RESETTING; adapter->flags |= IAVF_FLAG_RESET_PENDING; adapter->aq_required = 0; adapter->current_op = VIRTCHNL_OP_UNKNOWN;