Hello, syzbot found the following crash on: HEAD commit: e17994d1 usb: core: kcov: collect coverage from usb comple.. git tree: https://github.com/google/kasan.git usb-fuzzer console output: https://syzkaller.appspot.com/x/log.txt?x=1129afe3e00000 kernel config: https://syzkaller.appspot.com/x/.config?x=5d64370c438bc60 dashboard link: https://syzkaller.appspot.com/bug?extid=6d2e7f6fa90e27be9d62 compiler: gcc (GCC) 9.0.0 20181231 (experimental) Unfortunately, I don't have any reproducer for this crash yet. IMPORTANT: if you fix the bug, please add the following tag to the commit: Reported-by: syzbot+6d2e7f6fa90e27be9d62@xxxxxxxxxxxxxxxxxxxxxxxxx ------------[ cut here ]------------ ODEBUG: free active (active state 0) object type: work_struct hint: hfa384x_usb_defer+0x0/0x430 include/linux/list.h:71 WARNING: CPU: 0 PID: 95 at lib/debugobjects.c:485 debug_print_object+0x160/0x250 lib/debugobjects.c:485 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 95 Comm: kworker/0:2 Not tainted 5.6.0-rc5-syzkaller #0 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+0xef/0x16e lib/dump_stack.c:118 panic+0x2aa/0x6e1 kernel/panic.c:221 __warn.cold+0x2f/0x30 kernel/panic.c:582 report_bug+0x27b/0x2f0 lib/bug.c:195 fixup_bug arch/x86/kernel/traps.c:174 [inline] fixup_bug arch/x86/kernel/traps.c:169 [inline] do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:267 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:286 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1027 RIP: 0010:debug_print_object+0x160/0x250 lib/debugobjects.c:485 Code: dd 20 37 fc 85 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 bf 00 00 00 48 8b 14 dd 20 37 fc 85 48 c7 c7 60 2b fc 85 e8 98 0b 29 ff <0f> 0b 83 05 0b 3a fb 05 01 48 83 c4 20 5b 5d 41 5c 41 5d c3 48 89 RSP: 0018:ffff8881d58c76b0 EFLAGS: 00010286 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff812972fd RDI: ffffed103ab18ec8 RBP: 0000000000000001 R08: ffff8881d58b8000 R09: fffffbfff1266e8f R10: fffffbfff1266e8e R11: ffffffff89337477 R12: ffffffff870d8b00 R13: ffffffff8119f700 R14: ffff8881d963cd20 R15: ffff8881d35b8e38 __debug_check_no_obj_freed lib/debugobjects.c:967 [inline] debug_check_no_obj_freed+0x2e1/0x445 lib/debugobjects.c:998 slab_free_hook mm/slub.c:1441 [inline] slab_free_freelist_hook mm/slub.c:1477 [inline] slab_free mm/slub.c:3024 [inline] kfree+0x18a/0x300 mm/slub.c:3976 prism2sta_disconnect_usb+0x76e/0xc30 drivers/staging/wlan-ng/prism2usb.c:209 usb_unbind_interface+0x1bd/0x8a0 drivers/usb/core/driver.c:436 __device_release_driver drivers/base/dd.c:1137 [inline] device_release_driver_internal+0x42f/0x500 drivers/base/dd.c:1168 bus_remove_device+0x2eb/0x5a0 drivers/base/bus.c:533 device_del+0x481/0xd30 drivers/base/core.c:2677 usb_disable_device+0x23d/0x790 drivers/usb/core/message.c:1237 usb_disconnect+0x293/0x900 drivers/usb/core/hub.c:2211 hub_port_connect drivers/usb/core/hub.c:5046 [inline] hub_port_connect_change drivers/usb/core/hub.c:5335 [inline] port_event drivers/usb/core/hub.c:5481 [inline] hub_event+0x1a1d/0x4300 drivers/usb/core/hub.c:5563 process_one_work+0x94b/0x1620 kernel/workqueue.c:2264 process_scheduled_works kernel/workqueue.c:2326 [inline] worker_thread+0x7ab/0xe20 kernel/workqueue.c:2412 kthread+0x318/0x420 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Kernel Offset: disabled Rebooting in 86400 seconds.. --- This bug is generated by a bot. It may contain errors. See https://goo.gl/tpsmEJ for more information about syzbot. syzbot engineers can be reached at syzkaller@xxxxxxxxxxxxxxxx. syzbot will keep track of this bug report. See: https://goo.gl/tpsmEJ#status for how to communicate with syzbot.