syzbot

em28xx 1-1:0.44: Audio interface 44 found (Vendor Class)
em28xx 1-1:0.44: unknown em28xx chip ID (0)
em28xx 1-1:0.44: Config register raw data: 0xfffffffb
em28xx 1-1:0.44: AC97 chip type couldn't be determined
em28xx 1-1:0.44: No AC97 audio processor
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list_add corruption. prev->next should be next (ffffffff8753dbc0), but was ffffffff83501085. (prev=ffff8881c66d0240).
WARNING: CPU: 1 PID: 83 at lib/list_debug.c:26 __list_add_valid+0x99/0xf0 lib/list_debug.c:26
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 83 Comm: kworker/1:2 Not tainted 5.4.0-rc6+ #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+0xca/0x13e lib/dump_stack.c:113
 panic+0x2aa/0x6e1 kernel/panic.c:221
 __warn.cold+0x2f/0x33 kernel/panic.c:582
 report_bug+0x27b/0x2f0 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x12b/0x1e0 arch/x86/kernel/traps.c:272
 do_invalid_op+0x32/0x40 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:__list_add_valid+0x99/0xf0 lib/list_debug.c:26
Code: 48 c7 c7 80 ba da 85 e8 5a 31 30 ff 0f 0b 48 83 c4 08 31 c0 5d 41 5c c3 48 89 f1 48 c7 c7 40 bb da 85 4c 89 e6 e8 3c 31 30 ff <0f> 0b 31 c0 eb c5 48 89 f2 4c 89 e1 48 89 ee 48 c7 c7 c0 bb da 85
RSP: 0018:ffff8881d89df0e0 EFLAGS: 00010286
RAX: 0000000000000000 RBX: ffff8881cfb98120 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8128c9cd RDI: ffffed103b13be0e
RBP: ffff8881cfb98240 R08: ffff8881d8c6c800 R09: fffffbfff11ab3af
R10: fffffbfff11ab3ae R11: ffffffff88d59d77 R12: ffffffff8753dbc0
R13: ffff8881cfb98000 R14: ffff8881cfb9812c R15: ffff8881cf90d000
 __list_add include/linux/list.h:60 [inline]
 list_add_tail include/linux/list.h:93 [inline]
 em28xx_init_extension+0x44/0x1f0 drivers/media/usb/em28xx/em28xx-core.c:1125
 em28xx_init_dev.isra.0+0xa7b/0x15d8 drivers/media/usb/em28xx/em28xx-cards.c:3520
 em28xx_usb_probe.cold+0xcac/0x2516 drivers/media/usb/em28xx/em28xx-cards.c:3869
 usb_probe_interface+0x305/0x7a0 drivers/usb/core/driver.c:361
 really_probe+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x104/0x210 drivers/base/dd.c:721
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
 __device_attach+0x217/0x360 drivers/base/dd.c:894
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
 device_add+0xae6/0x16f0 drivers/base/core.c:2202
 usb_set_configuration+0xdf6/0x1670 drivers/usb/core/message.c:2023
 generic_probe+0x9d/0xd5 drivers/usb/core/generic.c:210
 usb_probe_device+0x99/0x100 drivers/usb/core/driver.c:266
 really_probe+0x281/0x6d0 drivers/base/dd.c:548
 driver_probe_device+0x104/0x210 drivers/base/dd.c:721
 __device_attach_driver+0x1c2/0x220 drivers/base/dd.c:828
 bus_for_each_drv+0x162/0x1e0 drivers/base/bus.c:430
 __device_attach+0x217/0x360 drivers/base/dd.c:894
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:490
 device_add+0xae6/0x16f0 drivers/base/core.c:2202
 usb_new_device.cold+0x6a4/0xe79 drivers/usb/core/hub.c:2537
 hub_port_connect drivers/usb/core/hub.c:5184 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5324 [inline]
 port_event drivers/usb/core/hub.c:5470 [inline]
 hub_event+0x1df8/0x3800 drivers/usb/core/hub.c:5552
 process_one_work+0x92b/0x1530 kernel/workqueue.c:2269
 process_scheduled_works kernel/workqueue.c:2331 [inline]
 worker_thread+0x7ab/0xe20 kernel/workqueue.c:2417
 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..