usb 2-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 2-1: Product: syz
usb 2-1: SerialNumber: syz
usb 2-1: USB disconnect, device number 41
------------[ cut here ]------------
WARNING: CPU: 1 PID: 22410 at lib/refco
WARNING: CPU: 1 PID: 22410 at lib/refcount.c:28 refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28
refcount_t: underflow; use-after-free.
Modules linked in:
Kernel panic - not syncing: kernel: panic_on_warn set ...
CPU: 1 UID: 0 PID: 22410 Comm: kworker/1:14 Not tainted syzkaller #0 PREEMPT 
Hardware name: ARM-Versatile Express
Workqueue: usb_hub_wq hub_event
Call trace: 
[<80201a24>] (dump_backtrace) from [<80201b20>] (show_stack+0x18/0x1c arch/arm/kernel/traps.c:257)
 r7:00000000 r6:8281f77c r5:00000000 r4:82260d04
[<80201b08>] (show_stack) from [<8021fc50>] (__dump_stack lib/dump_stack.c:94 [inline])
[<80201b08>] (show_stack) from [<8021fc50>] (dump_stack_lvl+0x54/0x7c lib/dump_stack.c:120)
[<8021fbfc>] (dump_stack_lvl) from [<8021fc90>] (dump_stack+0x18/0x1c lib/dump_stack.c:129)
 r5:00000000 r4:82a77d18
[<8021fc78>] (dump_stack) from [<80202624>] (vpanic+0x10c/0x30c kernel/panic.c:430)
[<80202518>] (vpanic) from [<80202858>] (trace_suspend_resume+0x0/0xd8 kernel/panic.c:566)
 r7:808bbe94
[<80202824>] (panic) from [<80254960>] (check_panic_on_warn kernel/panic.c:323 [inline])
[<80202824>] (panic) from [<80254960>] (get_taint+0x0/0x1c kernel/panic.c:318)
 r3:8280c684 r2:00000001 r1:82247720 r0:8224f19c
[<802548e8>] (check_panic_on_warn) from [<80254ac4>] (__warn+0x80/0x188 kernel/panic.c:837)
[<80254a44>] (__warn) from [<80254db4>] (warn_slowpath_fmt+0x1e8/0x1f4 kernel/panic.c:872)
 r8:00000009 r7:822b9818 r6:dfaddbfc r5:84ba6c00 r4:00000000
[<80254bd0>] (warn_slowpath_fmt) from [<808bbe94>] (refcount_warn_saturate+0x13c/0x174 lib/refcount.c:28)
 r10:00000100 r9:829d56bc r8:84f07888 r7:84f05074 r6:87935fb4 r5:84f05000
 r4:87935800
[<808bbd58>] (refcount_warn_saturate) from [<81a14448>] (__refcount_sub_and_test include/linux/refcount.h:400 [inline])
[<808bbd58>] (refcount_warn_saturate) from [<81a14448>] (__refcount_dec_and_test include/linux/refcount.h:432 [inline])
[<808bbd58>] (refcount_warn_saturate) from [<81a14448>] (refcount_dec_and_test include/linux/refcount.h:450 [inline])
[<808bbd58>] (refcount_warn_saturate) from [<81a14448>] (kref_put include/linux/kref.h:64 [inline])
[<808bbd58>] (refcount_warn_saturate) from [<81a14448>] (kobject_put+0x158/0x1f4 lib/kobject.c:737)
[<81a142f0>] (kobject_put) from [<80b3d9e4>] (put_device+0x18/0x1c drivers/base/core.c:3797)
 r7:84f05074 r6:87935fb4 r5:84f05000 r4:87935800
[<80b3d9cc>] (put_device) from [<81436ed0>] (hdm_disconnect+0x98/0x9c drivers/most/most_usb.c:1130)
[<81436e38>] (hdm_disconnect) from [<80e9d084>] (usb_unbind_interface+0x84/0x2bc drivers/usb/core/driver.c:458)
 r7:84f05074 r6:84f05030 r5:00000000 r4:84f07800
[<80e9d000>] (usb_unbind_interface) from [<80b45b60>] (device_remove drivers/base/dd.c:571 [inline])
[<80e9d000>] (usb_unbind_interface) from [<80b45b60>] (device_remove+0x64/0x6c drivers/base/dd.c:563)
 r10:00000100 r9:84f07888 r8:00000044 r7:84f05074 r6:829d56bc r5:00000000
 r4:84f05030
[<80b45afc>] (device_remove) from [<80b47050>] (__device_release_driver drivers/base/dd.c:1274 [inline])
[<80b45afc>] (device_remove) from [<80b47050>] (device_release_driver_internal+0x18c/0x200 drivers/base/dd.c:1297)
 r5:00000000 r4:84f05030
[<80b46ec4>] (device_release_driver_internal) from [<80b470dc>] (device_release_driver+0x18/0x1c drivers/base/dd.c:1320)
 r9:84f07888 r8:8335dd40 r7:8335dd38 r6:8335dd0c r5:84f05030 r4:8335dd30
[<80b470c4>] (device_release_driver) from [<80b451a0>] (bus_remove_device+0xcc/0x120 drivers/base/bus.c:579)
[<80b450d4>] (bus_remove_device) from [<80b3f438>] (device_del+0x148/0x38c drivers/base/core.c:3878)
 r9:84f07888 r8:84ba6c00 r7:04208060 r6:00000000 r5:84f05030 r4:84f05074
[<80b3f2f0>] (device_del) from [<80e9aac0>] (usb_disable_device+0xd4/0x1e8 drivers/usb/core/message.c:1418)
 r10:00000100 r9:00000000 r8:00000000 r7:84f05000 r6:84f07800 r5:8689bc48
 r4:00000007
[<80e9a9ec>] (usb_disable_device) from [<80e8f888>] (usb_disconnect+0xec/0x2ac drivers/usb/core/hub.c:2344)
 r9:853d7e00 r8:84f078cc r7:83e57800 r6:84f07888 r5:84f07800 r4:60000013
[<80e8f79c>] (usb_disconnect) from [<80e92884>] (hub_port_connect drivers/usb/core/hub.c:5406 [inline])
[<80e8f79c>] (usb_disconnect) from [<80e92884>] (hub_port_connect_change drivers/usb/core/hub.c:5706 [inline])
[<80e8f79c>] (usb_disconnect) from [<80e92884>] (port_event drivers/usb/core/hub.c:5870 [inline])
[<80e8f79c>] (usb_disconnect) from [<80e92884>] (hub_event+0x1194/0x1950 drivers/usb/core/hub.c:5952)
 r10:00000100 r9:83d2892c r8:83e57000 r7:84f07800 r6:83d28200 r5:00000001
 r4:00000001
[<80e916f0>] (hub_event) from [<8027a398>] (process_one_work+0x1b4/0x4f4 kernel/workqueue.c:3236)
 r10:8335df70 r9:83274005 r8:84ba6c00 r7:ddde2d40 r6:83274000 r5:83d2892c
 r4:847f4c00
[<8027a1e4>] (process_one_work) from [<8027afe0>] (process_scheduled_works kernel/workqueue.c:3319 [inline])
[<8027a1e4>] (process_one_work) from [<8027afe0>] (worker_thread+0x1fc/0x3d8 kernel/workqueue.c:3400)
 r10:61c88647 r9:84ba6c00 r8:847f4c2c r7:82804d40 r6:ddde2d40 r5:ddde2d60
 r4:847f4c00
[<8027ade4>] (worker_thread) from [<80281fcc>] (kthread+0x12c/0x280 kernel/kthread.c:463)
 r10:00000000 r9:847f4c00 r8:8027ade4 r7:dfb4de60 r6:847f4280 r5:84ba6c00
 r4:00000001
[<80281ea0>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137)
Exception stack(0xdfaddfb0 to 0xdfaddff8)
dfa0:                                     00000000 00000000 00000000 00000000
dfc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
dfe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r10:00000000 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:80281ea0
 r4:8488b300
Rebooting in 86400 seconds..