Recently I got a Caldigit TS3 Thunderbolt 3 dock, and noticed that upon hotplugging my kernel would immediately crash due to igb:

[ 680.825801] kernel BUG at drivers/pci/msi.c:352! [ 680.828388] invalid opcode: 0000 [#1] SMP [ 680.829194] Modules linked in: igb(O) thunderbolt i2c_algo_bit joydev vfat fat btusb btrtl btbcm btintel bluetooth ecdh_generic hp_wmi sparse_keymap rfkill wmi_bmof iTCO_wdt intel_rapl x86_pkg_temp_thermal coretemp crc32_pclmul snd_pcm rtsx_pci_ms mei_me snd_timer memstick snd pcspkr mei soundcore i2c_i801 tpm_tis psmouse shpchp wmi tpm_tis_core tpm video hp_wireless acpi_pad rtsx_pci_sdmmc mmc_core crc32c_intel serio_raw rtsx_pci mfd_core xhci_pci xhci_hcd i2c_hid i2c_core [last unloaded: igb] [ 680.831085] CPU: 1 PID: 78 Comm: kworker/u16:1 Tainted: G O 4.15.0-rc3Lyude-Test+ #6 [ 680.831596] Hardware name: HP HP ZBook Studio G4/826B, BIOS P71 Ver. 01.03 06/09/2017 [ 680.832168] Workqueue: kacpi_hotplug acpi_hotplug_work_fn [ 680.832687] RIP: 0010:free_msi_irqs+0x180/0x1b0 [ 680.833271] RSP: 0018:ffffc9000030fbf0 EFLAGS: 00010286 [ 680.833761] RAX: ffff8803405f9c00 RBX: ffff88033e3d2e40 RCX: 000000000000002c [ 680.834278] RDX: 0000000000000000 RSI: 00000000000000ac RDI: ffff880340be2178 [ 680.834832] RBP: 0000000000000000 R08: ffff880340be1ff0 R09: ffff8803405f9c00 [ 680.835342] R10: 0000000000000000 R11: 0000000000000040 R12: ffff88033d63a298 [ 680.835822] R13: ffff88033d63a000 R14: 0000000000000060 R15: ffff880341959000 [ 680.836332] FS: 0000000000000000(0000) GS:ffff88034f440000(0000) knlGS:0000000000000000 [ 680.836817] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 680.837360] CR2: 000055e64044afdf CR3: 0000000001c09002 CR4: 00000000003606e0 [ 680.837954] Call Trace: [ 680.838853] pci_disable_msix+0xce/0xf0 [ 680.839616] igb_reset_interrupt_capability+0x5d/0x60 [igb] [ 680.840278] igb_remove+0x9d/0x110 [igb] [ 680.840764] pci_device_remove+0x36/0xb0 [ 680.841279] device_release_driver_internal+0x157/0x220 [ 680.841739] pci_stop_bus_device+0x7d/0xa0 [ 680.842255] pci_stop_bus_device+0x2b/0xa0 [ 680.842722] pci_stop_bus_device+0x3d/0xa0 [ 680.843189] pci_stop_and_remove_bus_device+0xe/0x20 [ 680.843627] trim_stale_devices+0xf3/0x140 [ 680.844086] trim_stale_devices+0x94/0x140 [ 680.844532] trim_stale_devices+0xa6/0x140 [ 680.845031] ? get_slot_status+0x90/0xc0 [ 680.845536] acpiphp_check_bridge.part.5+0xfe/0x140 [ 680.846021] acpiphp_hotplug_notify+0x175/0x200 [ 680.846581] ? free_bridge+0x100/0x100 [ 680.847113] acpi_device_hotplug+0x8a/0x490 [ 680.847535] acpi_hotplug_work_fn+0x1a/0x30 [ 680.848076] process_one_work+0x182/0x3a0 [ 680.848543] worker_thread+0x2e/0x380 [ 680.848963] ? process_one_work+0x3a0/0x3a0 [ 680.849373] kthread+0x111/0x130 [ 680.849776] ? kthread_create_worker_on_cpu+0x50/0x50 [ 680.850188] ret_from_fork+0x1f/0x30 [ 680.850601] Code: 43 14 85 c0 0f 84 d5 fe ff ff 31 ed eb 0f 83 c5 01 39 6b 14 0f 86 c5 fe ff ff 8b 7b 10 01 ef e8 b7 e4 d2 ff 48 83 78 70 00 74 e3 <0f> 0b 49 8d b5 a0 00 00 00 e8 62 6f d3 ff e9 c7 fe ff ff 48 8b [ 680.851497] RIP: free_msi_irqs+0x180/0x1b0 RSP: ffffc9000030fbf0

As it turns out, normally the freeing of IRQs that would fix this is called inside of the scope of __igb_close(). However, since the device is already gone by the point we try to unregister the netdevice from the driver due to a hotplug we end up seeing that the netif isn't present and thus, forget to free any of the device IRQs.

So: make sure that if we're in the process of dismantling the netdev, we always allow __igb_close() to be called so that IRQs may be freed normally. Additionally, only allow igb_close() to be called from __igb_close() if it hasn't already been called for the given adapter.

Signed-off-by: Lyude Paul lyude@redhat.com Fixes: 9474933caf21 ("igb: close/suspend race in netif_device_detach") Cc: Todd Fujinaka todd.fujinaka@intel.com Cc: Stephen Hemminger stephen@networkplumber.org Cc: stable@vger.kernel.org --- Changes since v1: - Remove code for freeing IRQs from igb_remove(), unbreak __igb_close() instead (re: Stephen Hemminger)

drivers/net/ethernet/intel/igb/igb_main.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/intel/igb/igb_main.c b/drivers/net/ethernet/intel/igb/igb_main.c index c208753ff5b7..a1083fd074dd 100644 --- a/drivers/net/ethernet/intel/igb/igb_main.c +++ b/drivers/net/ethernet/intel/igb/igb_main.c @@ -3663,7 +3663,9 @@ static int __igb_close(struct net_device *netdev, bool suspending) if (!suspending) pm_runtime_get_sync(&pdev->dev);

- igb_down(adapter); + if (!test_bit(__IGB_DOWN, &adapter->state)) + igb_down(adapter); + igb_free_irq(adapter);

igb_free_all_tx_resources(adapter); @@ -3676,7 +3678,7 @@ static int __igb_close(struct net_device *netdev, bool suspending)

int igb_close(struct net_device *netdev) { - if (netif_device_present(netdev)) + if (netif_device_present(netdev) || netdev->dismantle) return __igb_close(netdev, false); return 0; }