Trying to probe a mt7921e pci card without firmware results in a successful probe where ieee80211_register_hw hasn't been called. When removing the driver, ieee802111_unregister_hw is called unconditionally leading to a kernel NULL pointer dereference among other things.
As with other drivers that delay registration after probe, we track the registration state in a flag variable and conidtionalize deregistration. Link: https://bugs.debian.org/1029116 Link: https://bugs.kali.org/view.php?id=8140 Reported-by: Stuart Hayhurst <stuart.a.hayhu...@gmail.com> Fixes: 1c71e03afe4b ("mt76: mt7921: move mt7921_init_hw in a dedicated work") Signed-off-by: Helmut Grohne <hel...@freexian.com> Cc: sta...@vger.kernel.org Sponsored-by: Freexian and Offensive Security --- drivers/net/wireless/mediatek/mt76/mt7921/init.c | 1 + drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h | 1 + drivers/net/wireless/mediatek/mt76/mt7921/pci.c | 3 ++- drivers/net/wireless/mediatek/mt76/mt7921/sdio.c | 3 ++- drivers/net/wireless/mediatek/mt76/mt7921/usb.c | 3 ++- 5 files changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/init.c b/drivers/net/wireless/mediatek/mt76/mt7921/init.c index 542dfd425129..d5438212d5ff 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/init.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/init.c @@ -315,6 +315,7 @@ static void mt7921_init_work(struct work_struct *work) dev_err(dev->mt76.dev, "register device failed\n"); return; } + dev->hw_registered = true; ret = mt7921_init_debugfs(dev); if (ret) { diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h index 15d6b7fe1c6c..e3b5d8ebf243 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h +++ b/drivers/net/wireless/mediatek/mt76/mt7921/mt7921.h @@ -288,6 +288,7 @@ struct mt7921_dev { bool hw_full_reset:1; bool hw_init_done:1; bool fw_assert:1; + bool hw_registered:1; struct list_head sta_poll_list; spinlock_t sta_poll_lock; diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c index cb72ded37256..1841eb7345dc 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/pci.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/pci.c @@ -110,7 +110,8 @@ static void mt7921e_unregister_device(struct mt7921_dev *dev) struct mt76_connac_pm *pm = &dev->pm; cancel_work_sync(&dev->init_work); - mt76_unregister_device(&dev->mt76); + if (dev->hw_registered) + mt76_unregister_device(&dev->mt76); mt76_for_each_q_rx(&dev->mt76, i) napi_disable(&dev->mt76.napi[i]); cancel_delayed_work_sync(&pm->ps_work); diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c index 8ce4252b8ae7..23a9dd3c6450 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/sdio.c @@ -43,7 +43,8 @@ static void mt7921s_unregister_device(struct mt7921_dev *dev) struct mt76_connac_pm *pm = &dev->pm; cancel_work_sync(&dev->init_work); - mt76_unregister_device(&dev->mt76); + if (dev->hw_registered) + mt76_unregister_device(&dev->mt76); cancel_delayed_work_sync(&pm->ps_work); cancel_work_sync(&pm->wake_work); diff --git a/drivers/net/wireless/mediatek/mt76/mt7921/usb.c b/drivers/net/wireless/mediatek/mt76/mt7921/usb.c index 5321d20dcdcb..e55e1b50f760 100644 --- a/drivers/net/wireless/mediatek/mt76/mt7921/usb.c +++ b/drivers/net/wireless/mediatek/mt76/mt7921/usb.c @@ -301,7 +301,8 @@ static void mt7921u_disconnect(struct usb_interface *usb_intf) if (!test_bit(MT76_STATE_INITIALIZED, &dev->mphy.state)) return; - mt76_unregister_device(&dev->mt76); + if (dev->hw_registered) + mt76_unregister_device(&dev->mt76); mt7921u_cleanup(dev); usb_set_intfdata(usb_intf, NULL); -- 2.39.0
