hid-u2fzero 0003:10C4:8ACF.0004: unknown main item tag 0x0 hid-u2fzero 0003:10C4:8ACF.0004: hidraw0: USB HID v0.00 Device [HID 10c4:8acf] on usb-dummy_hcd.4-1/input0 hid-u2fzero 0003:10C4:8ACF.0004: U2F Zero LED initialised general protection fault, probably for non-canonical address 0xdffffc0000000015: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x00000000000000a8-0x00000000000000af] CPU: 0 PID: 2354 Comm: kworker/0:3 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:u2fzero_recv drivers/hid/hid-u2fzero.c:116 [inline] RIP: 0010:u2fzero_rng_read+0x256/0x750 drivers/hid/hid-u2fzero.c:202 Code: d9 74 12 4c 89 ef e8 09 b4 4e fa 48 b9 00 00 00 00 00 fc ff df bb a8 00 00 00 4c 89 6c 24 18 49 03 5d 00 48 89 d8 48 c1 e8 03 <80> 3c 08 00 74 08 48 89 df e8 5c b4 4e fa 48 8d 84 24 80 00 00 00 RSP: 0018:ffffc900063a67c0 EFLAGS: 00010202 RAX: 0000000000000015 RBX: 00000000000000a8 RCX: dffffc0000000000 RDX: 000000000000003b RSI: 0000000000000000 RDI: ffff88807bccda69 RBP: ffffc900063a6978 R08: 0000000000000000 R09: ffff88807bccda2e R10: dffffc0000000000 R11: ffffed100f799b4d R12: 1ffff1100f5d6a06 R13: ffff88807aeb5030 R14: ffff88807aeb5388 R15: 1ffff92000c74d04 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055fa7d570168 CR3: 000000005f9d2000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rng_get_data drivers/char/hw_random/core.c:196 [inline] add_early_randomness+0x7a/0x150 drivers/char/hw_random/core.c:74 hwrng_register+0x42d/0x4b0 drivers/char/hw_random/core.c:526 devm_hwrng_register+0x43/0xb0 drivers/char/hw_random/core.c:597 u2fzero_probe+0x26e/0x2f0 drivers/hid/hid-u2fzero.c:336 hid_device_probe+0x271/0x360 drivers/hid/hid-core.c:2323 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 hid_add_device+0x389/0x530 drivers/hid/hid-core.c:2475 usbhid_probe+0xb92/0xf40 drivers/hid/usbhid/hid-core.c:1442 usb_probe_interface+0x5c5/0xb20 drivers/usb/core/driver.c:396 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_set_configuration+0x1991/0x1fd0 drivers/usb/core/message.c:2165 usb_generic_driver_probe+0x89/0x150 drivers/usb/core/generic.c:238 usb_probe_device+0x139/0x270 drivers/usb/core/driver.c:293 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x284/0xc80 drivers/base/dd.c:595 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:755 driver_probe_device+0x4f/0x420 drivers/base/dd.c:785 __device_attach_driver+0x2b0/0x500 drivers/base/dd.c:907 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:979 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3412 usb_new_device+0xd65/0x1660 drivers/usb/core/hub.c:2632 hub_port_connect drivers/usb/core/hub.c:5497 [inline] hub_port_connect_change drivers/usb/core/hub.c:5637 [inline] port_event drivers/usb/core/hub.c:5799 [inline] hub_event+0x2e4a/0x55e0 drivers/usb/core/hub.c:5881 process_one_work+0x85f/0x1010 kernel/workqueue.c:2310 worker_thread+0xaa6/0x1290 kernel/workqueue.c:2457 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 Modules linked in: ---[ end trace 5f95ae5a83039767 ]--- RIP: 0010:u2fzero_recv drivers/hid/hid-u2fzero.c:116 [inline] RIP: 0010:u2fzero_rng_read+0x256/0x750 drivers/hid/hid-u2fzero.c:202 Code: d9 74 12 4c 89 ef e8 09 b4 4e fa 48 b9 00 00 00 00 00 fc ff df bb a8 00 00 00 4c 89 6c 24 18 49 03 5d 00 48 89 d8 48 c1 e8 03 <80> 3c 08 00 74 08 48 89 df e8 5c b4 4e fa 48 8d 84 24 80 00 00 00 RSP: 0018:ffffc900063a67c0 EFLAGS: 00010202 RAX: 0000000000000015 RBX: 00000000000000a8 RCX: dffffc0000000000 RDX: 000000000000003b RSI: 0000000000000000 RDI: ffff88807bccda69 RBP: ffffc900063a6978 R08: 0000000000000000 R09: ffff88807bccda2e R10: dffffc0000000000 R11: ffffed100f799b4d R12: 1ffff1100f5d6a06 R13: ffff88807aeb5030 R14: ffff88807aeb5388 R15: 1ffff92000c74d04 FS: 0000000000000000(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7feecb46c8 CR3: 000000002a1c1000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: d9 74 12 4c fnstenv 0x4c(%rdx,%rdx,1) 4: 89 ef mov %ebp,%edi 6: e8 09 b4 4e fa call 0xfa4eb414 b: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 12: fc ff df 15: bb a8 00 00 00 mov $0xa8,%ebx 1a: 4c 89 6c 24 18 mov %r13,0x18(%rsp) 1f: 49 03 5d 00 add 0x0(%r13),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 08 00 cmpb $0x0,(%rax,%rcx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 48 89 df mov %rbx,%rdi 33: e8 5c b4 4e fa call 0xfa4eb494 38: 48 8d 84 24 80 00 00 lea 0x80(%rsp),%rax 3f: 00