From: Rustam Kovhaev <rkovhaev@xxxxxxxxx> commit b4383c971bc5263efe2b0915ba67ebf2bf3f1ee5 upstream. when firmware fails to load we should not call unregister_netdev() this patch fixes a race condition between rtl871x_load_fw_cb() and r871xu_dev_remove() and fixes the bug reported by syzbot Reported-by: syzbot+80899a8a8efe8968cde7@xxxxxxxxxxxxxxxxxxxxxxxxx Link: https://syzkaller.appspot.com/bug?extid=80899a8a8efe8968cde7 Signed-off-by: Rustam Kovhaev <rkovhaev@xxxxxxxxx> Cc: stable <stable@xxxxxxxxxxxxxxx> Link: https://lore.kernel.org/r/20200716151324.1036204-1-rkovhaev@xxxxxxxxx Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/staging/rtl8712/hal_init.c | 3 ++- drivers/staging/rtl8712/usb_intf.c | 11 ++++++++--- 2 files changed, 10 insertions(+), 4 deletions(-) --- a/drivers/staging/rtl8712/hal_init.c +++ b/drivers/staging/rtl8712/hal_init.c @@ -33,7 +33,6 @@ static void rtl871x_load_fw_cb(const str { struct _adapter *adapter = context; - complete(&adapter->rtl8712_fw_ready); if (!firmware) { struct usb_device *udev = adapter->dvobjpriv.pusbdev; struct usb_interface *usb_intf = adapter->pusb_intf; @@ -41,11 +40,13 @@ static void rtl871x_load_fw_cb(const str dev_err(&udev->dev, "r8712u: Firmware request failed\n"); usb_put_dev(udev); usb_set_intfdata(usb_intf, NULL); + complete(&adapter->rtl8712_fw_ready); return; } adapter->fw = firmware; /* firmware available - start netdev */ register_netdev(adapter->pnetdev); + complete(&adapter->rtl8712_fw_ready); } static const char firmware_file[] = "rtlwifi/rtl8712u.bin"; --- a/drivers/staging/rtl8712/usb_intf.c +++ b/drivers/staging/rtl8712/usb_intf.c @@ -595,13 +595,17 @@ static void r871xu_dev_remove(struct usb if (pnetdev) { struct _adapter *padapter = netdev_priv(pnetdev); - usb_set_intfdata(pusb_intf, NULL); - release_firmware(padapter->fw); /* never exit with a firmware callback pending */ wait_for_completion(&padapter->rtl8712_fw_ready); + pnetdev = usb_get_intfdata(pusb_intf); + usb_set_intfdata(pusb_intf, NULL); + if (!pnetdev) + goto firmware_load_fail; + release_firmware(padapter->fw); if (drvpriv.drv_registered) padapter->surprise_removed = true; - unregister_netdev(pnetdev); /* will call netdev_close() */ + if (pnetdev->reg_state != NETREG_UNINITIALIZED) + unregister_netdev(pnetdev); /* will call netdev_close() */ flush_scheduled_work(); udelay(1); /* Stop driver mlme relation timer */ @@ -614,6 +618,7 @@ static void r871xu_dev_remove(struct usb */ usb_put_dev(udev); } +firmware_load_fail: /* If we didn't unplug usb dongle and remove/insert module, driver * fails on sitesurvey for the first time when device is up. * Reset usb port for sitesurvey fail issue.
