Am Mittwoch, den 07.08.2019, 16:03 +0200 schrieb Andrey Konovalov: I may offer a preliminary analysis. Regards Oliver > On Fri, Apr 12, 2019 at 1:32 PM Andrey Konovalov <andreyknvl@xxxxxxxxxx> wrote: > > > > On Fri, Apr 12, 2019 at 1:29 AM syzbot > > <syzbot+40918e4d826fb2ff9b96@xxxxxxxxxxxxxxxxxxxxxxxxx> wrote: > > > > > > syzbot has found a reproducer for the following crash on: > > > > > > HEAD commit: 9a33b369 usb-fuzzer: main usb gadget fuzzer driver > > > git tree: https://github.com/google/kasan/tree/usb-fuzzer > > > console output: https://syzkaller.appspot.com/x/log.txt?x=10d552b7200000 > > > kernel config: https://syzkaller.appspot.com/x/.config?x=23e37f59d94ddd15 > > > dashboard link: https://syzkaller.appspot.com/bug?extid=40918e4d826fb2ff9b96 > > > compiler: gcc (GCC) 9.0.0 20181231 (experimental) > > > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=17a4c1af200000 > > > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=121b274b200000 > > > > > > IMPORTANT: if you fix the bug, please add the following tag to the commit: > > > Reported-by: syzbot+40918e4d826fb2ff9b96@xxxxxxxxxxxxxxxxxxxxxxxxx > > > > > > usb 1-1: r8712u: MAC Address from efuse = 00:e0:4c:87:00:00 > > > usb 1-1: r8712u: Loading firmware from "rtlwifi/rtl8712u.bin" > > > usb 1-1: USB disconnect, device number 2 Disconnect will run which leads to static void r871xu_dev_remove(struct usb_interface *pusb_intf) { struct net_device *pnetdev = usb_get_intfdata(pusb_intf); struct usb_device *udev = interface_to_usbdev(pusb_intf); if (pnetdev) { ^^^ This is supposed to save us 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); if (drvpriv.drv_registered) padapter->surprise_removed = true; unregister_netdev(pnetdev); /* will call netdev_close() */ So we will call unregister_netdev() > > > usb 1-1: Direct firmware load for rtlwifi/rtl8712u.bin failed with error -2 > > > usb 1-1: r8712u: Firmware request failed So we ran into the error handling of: static void rtl871x_load_fw_cb(const struct firmware *firmware, void *context) { 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; dev_err(&udev->dev, "r8712u: Firmware request failed\n"); usb_put_dev(udev); usb_set_intfdata(usb_intf, NULL); ^^^ This is supposed to save us from deregistering an unregistered device but it comes too late. We have already called complete. return; } adapter->fw = firmware; /* firmware available - start netdev */ register_netdev(adapter->pnetdev); register_netdev() is not called. > > > Kernel panic - not syncing: panic_on_warn set ... > > > CPU: 0 PID: 575 Comm: kworker/0:4 Not tainted 5.1.0-rc4-319354-g9a33b36 #3 > > > Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS > > > Google 01/01/2011 > > > Workqueue: usb_hub_wq hub_event > > > Call Trace: > > > __dump_stack lib/dump_stack.c:77 [inline] > > > dump_stack+0xe8/0x16e lib/dump_stack.c:113 > > > panic+0x29d/0x5f2 kernel/panic.c:214 > > > __warn.cold+0x20/0x48 kernel/panic.c:571 > > > report_bug+0x262/0x2a0 lib/bug.c:186 > > > fixup_bug arch/x86/kernel/traps.c:179 [inline] > > > fixup_bug arch/x86/kernel/traps.c:174 [inline] > > > do_error_trap+0x130/0x1f0 arch/x86/kernel/traps.c:272 > > > do_invalid_op+0x37/0x40 arch/x86/kernel/traps.c:291 > > > invalid_op+0x14/0x20 arch/x86/entry/entry_64.S:973 This kills us. > > > RIP: 0010:rollback_registered_many+0x1f3/0xe70 net/core/dev.c:8152 > > > Code: 05 00 00 31 ff 44 89 fe e8 5a 15 f3 f4 45 84 ff 0f 85 49 ff ff ff e8 > > > 1c 14 f3 f4 0f 1f 44 00 00 e8 12 14 f3 f4 e8 0d 14 f3 f4 <0f> 0b 4c 89 e7 > > > e8 33 72 f2 f6 31 ff 41 89 c4 89 c6 e8 27 15 f3 f4 > > > RSP: 0018:ffff88809d087698 EFLAGS: 00010293 > > > RAX: ffff88809d058000 RBX: ffff888096240000 RCX: ffffffff8c7eb146 > > > RDX: 0000000000000000 RSI: ffffffff8c7eb163 RDI: 0000000000000001 > > > RBP: ffff88809d0877c8 R08: ffff88809d058000 R09: fffffbfff2708111 > > > R10: fffffbfff2708110 R11: ffffffff93840887 R12: ffff888096240070 > > > R13: dffffc0000000000 R14: ffff88809d087758 R15: 0000000000000000 > > > rollback_registered+0xf7/0x1c0 net/core/dev.c:8228 > > > unregister_netdevice_queue net/core/dev.c:9275 [inline] > > > unregister_netdevice_queue+0x1dc/0x2b0 net/core/dev.c:9268 > > > unregister_netdevice include/linux/netdevice.h:2655 [inline] > > > unregister_netdev+0x1d/0x30 net/core/dev.c:9316 > > > r871xu_dev_remove+0xe7/0x223 drivers/staging/rtl8712/usb_intf.c:604 We end up here: static void rollback_registered_many(struct list_head *head) { struct net_device *dev, *tmp; LIST_HEAD(close_head); BUG_ON(dev_boot_phase); ASSERT_RTNL(); list_for_each_entry_safe(dev, tmp, head, unreg_list) { /* Some devices call without registering * for initialization unwind. Remove those * devices and proceed with the remaining. */ if (dev->reg_state == NETREG_UNINITIALIZED) { pr_debug("unregister_netdevice: device %s/%p never was registered\n", dev->name, dev); WARN_ON(1);
