batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
vhci_hcd: cannot find a urb of seqnum 2147483648 max seqnum 0
vhci_hcd: connection closed
==================================================================
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
BUG: KASAN: null-ptr-deref in atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
BUG: KASAN: null-ptr-deref in kthread_stop+0x72/0x6b0 kernel/kthread.c:583
Write of size 4 at addr 000000000000001c by task kworker/u4:5/9096

CPU: 1 PID: 9096 Comm: kworker/u4:5 Not tainted 4.19.179-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usbip_event event_handler
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1fc/0x2ef lib/dump_stack.c:118
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
 kasan_report_error.cold+0x15b/0x1b9 mm/kasan/report.c:352
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
 kasan_report+0x8f/0xa0 mm/kasan/report.c:412
 atomic_inc include/asm-generic/atomic-instrumented.h:109 [inline]
 kthread_stop+0x72/0x6b0 kernel/kthread.c:583
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
 vhci_shutdown_connection+0x14e/0x280 drivers/usb/usbip/vhci_hcd.c:1023
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
 event_handler+0x1f0/0x4f0 drivers/usb/usbip/usbip_event.c:78
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
 process_one_work+0x864/0x1570 kernel/workqueue.c:2152
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
batman_adv: The newly added mac address (aa:aa:aa:aa:aa:3d) already exists on: batadv_slave_0
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2295
batman_adv: It is strongly recommended to keep mac addresses unique to avoid problems!
IPv6: ADDRCONF(NETDEV_UP): batadv_slave_0: link is not ready
batman_adv: batadv0: Interface activated: batadv_slave_0
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
==================================================================
IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready