hid-u2fzero 0003:10C4:8ACF.0001: unknown main item tag 0x0 hid-u2fzero 0003:10C4:8ACF.0001: hidraw0: USB HID v0.00 Device [HID 10c4:8acf] on usb-dummy_hcd.3-1/input0 hid-u2fzero 0003:10C4:8ACF.0001: 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: 1 PID: 4383 Comm: kworker/1:6 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 Workqueue: usb_hub_wq hub_event RIP: 0010:u2fzero_recv drivers/hid/hid-u2fzero.c:137 [inline] RIP: 0010:u2fzero_rng_read+0x295/0x740 drivers/hid/hid-u2fzero.c:223 Code: 80 3c 28 00 49 89 c5 74 08 4c 89 ff e8 a4 49 1a fa bb a8 00 00 00 49 03 1f 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 fd 49 1a fa 48 8d 44 24 60 48 89 03 RSP: 0018:ffffc90004a8e7e0 EFLAGS: 00010202 RAX: 0000000000000015 RBX: 00000000000000a8 RCX: dffffc0000000000 RDX: 000000000000003b RSI: 0000000000000000 RDI: ffff8880777d2169 RBP: ffffc90004a8e970 R08: 0000000000000000 R09: ffff8880777d212e R10: dffffc0000000000 R11: ffffed100eefa42d R12: 1ffff92000951d04 R13: 1ffff1100fcc5606 R14: 1ffff1100fcc567c R15: ffff88807e62b030 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffe4b923eb0 CR3: 000000005af49000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rng_get_data drivers/char/hw_random/core.c:201 [inline] add_early_randomness+0x7a/0x150 drivers/char/hw_random/core.c:73 hwrng_register+0x398/0x440 drivers/char/hw_random/core.c:593 devm_hwrng_register+0x43/0xb0 drivers/char/hw_random/core.c:665 u2fzero_probe+0x355/0x470 drivers/hid/hid-u2fzero.c:359 hid_device_probe+0x25c/0x350 drivers/hid/hid-core.c:2646 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x2aa/0xc70 drivers/base/dd.c:639 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:785 driver_probe_device+0x4f/0x420 drivers/base/dd.c:815 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:1015 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3697 hid_add_device+0x389/0x530 drivers/hid/hid-core.c:2798 usbhid_probe+0xc09/0xfe0 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+0x2aa/0xc70 drivers/base/dd.c:639 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:785 driver_probe_device+0x4f/0x420 drivers/base/dd.c:815 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:1015 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3697 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+0x2aa/0xc70 drivers/base/dd.c:639 __driver_probe_device+0x18c/0x330 drivers/base/dd.c:785 driver_probe_device+0x4f/0x420 drivers/base/dd.c:815 __device_attach_driver+0x2c6/0x510 drivers/base/dd.c:943 bus_for_each_drv+0x184/0x210 drivers/base/bus.c:429 __device_attach+0x2a8/0x480 drivers/base/dd.c:1015 bus_probe_device+0xbc/0x1e0 drivers/base/bus.c:489 device_add+0xa00/0xfb0 drivers/base/core.c:3697 usb_new_device+0xd66/0x1650 drivers/usb/core/hub.c:2659 hub_port_connect drivers/usb/core/hub.c:5517 [inline] hub_port_connect_change drivers/usb/core/hub.c:5657 [inline] port_event drivers/usb/core/hub.c:5817 [inline] hub_event+0x2dcf/0x5560 drivers/usb/core/hub.c:5899 process_one_work+0x8a2/0x1160 kernel/workqueue.c:2292 worker_thread+0xaa2/0x1270 kernel/workqueue.c:2439 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:u2fzero_recv drivers/hid/hid-u2fzero.c:137 [inline] RIP: 0010:u2fzero_rng_read+0x295/0x740 drivers/hid/hid-u2fzero.c:223 Code: 80 3c 28 00 49 89 c5 74 08 4c 89 ff e8 a4 49 1a fa bb a8 00 00 00 49 03 1f 48 89 d8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <80> 3c 08 00 74 08 48 89 df e8 fd 49 1a fa 48 8d 44 24 60 48 89 03 RSP: 0018:ffffc90004a8e7e0 EFLAGS: 00010202 RAX: 0000000000000015 RBX: 00000000000000a8 RCX: dffffc0000000000 RDX: 000000000000003b RSI: 0000000000000000 RDI: ffff8880777d2169 RBP: ffffc90004a8e970 R08: 0000000000000000 R09: ffff8880777d212e R10: dffffc0000000000 R11: ffffed100eefa42d R12: 1ffff92000951d04 R13: 1ffff1100fcc5606 R14: 1ffff1100fcc567c R15: ffff88807e62b030 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3bd0de5ba0 CR3: 000000001ef26000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 80 3c 28 00 cmpb $0x0,(%rax,%rbp,1) 4: 49 89 c5 mov %rax,%r13 7: 74 08 je 0x11 9: 4c 89 ff mov %r15,%rdi c: e8 a4 49 1a fa call 0xfa1a49b5 11: bb a8 00 00 00 mov $0xa8,%ebx 16: 49 03 1f add (%r15),%rbx 19: 48 89 d8 mov %rbx,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 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 fd 49 1a fa call 0xfa1a4a35 38: 48 8d 44 24 60 lea 0x60(%rsp),%rax 3d: 48 89 03 mov %rax,(%rbx)