dummy_hcd dummy_hcd.0: remove, state 4 usb usb1: USB disconnect, device number 1 dummy_hcd dummy_hcd.0: stopped dummy_hcd dummy_hcd.0: USB bus 1 deregistered general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 0 PID: 5931 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:dummy_udc_start+0xcd/0x1e0 drivers/usb/gadget/udc/dummy_hcd.c:1003 Code: 41 83 ff 03 74 18 41 83 ff 05 0f 85 8e 00 00 00 e8 f8 2c cd fa eb 0c e8 f1 2c cd fa eb 05 e8 ea 2c cd fa 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 24 aa 25 fb 4d 8b 36 4c 89 f7 e8 RSP: 0018:ffffc900046ff850 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88807ae4c050 RCX: ffff88807b2a8000 RDX: 0000000000000000 RSI: ffffffff8de003c0 RDI: 0000000000000001 RBP: ffff888025f12000 R08: ffff88807b2a8000 R09: 0000000000000004 R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 000055555eaa3500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3e60d87180 CR3: 000000002bdd7000 CR4: 00000000003506f0 Call Trace: usb_gadget_udc_start_locked drivers/usb/gadget/udc/core.c:1227 [inline] gadget_bind_driver+0x390/0x770 drivers/usb/gadget/udc/core.c:1656 call_driver_probe drivers/base/dd.c:-1 [inline] really_probe+0x247/0xae0 drivers/base/dd.c:717 __driver_probe_device+0x1f5/0x390 drivers/base/dd.c:879 driver_probe_device+0x4f/0x420 drivers/base/dd.c:909 __driver_attach+0x444/0x6d0 drivers/base/dd.c:1295 bus_for_each_dev+0x235/0x2b0 drivers/base/bus.c:370 bus_add_driver+0x340/0x630 drivers/base/bus.c:723 driver_register+0x23a/0x310 drivers/base/driver.c:246 usb_gadget_register_driver_owner+0xf9/0x270 drivers/usb/gadget/udc/core.c:1730 raw_ioctl_run drivers/usb/gadget/legacy/raw_gadget.c:549 [inline] raw_ioctl+0x1613/0x3d80 drivers/usb/gadget/legacy/raw_gadget.c:1262 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:871 [inline] __se_sys_ioctl+0xfd/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f3e60d9dcab Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fffcc634ba0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f3e60d9dcab RDX: 0000000000000000 RSI: 0000000000005501 RDI: 0000000000000004 RBP: 00007fffcc635c70 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000200000000280 R14: 0000000000000001 R15: 0000000000000000 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:dummy_udc_start+0xcd/0x1e0 drivers/usb/gadget/udc/dummy_hcd.c:1003 Code: 41 83 ff 03 74 18 41 83 ff 05 0f 85 8e 00 00 00 e8 f8 2c cd fa eb 0c e8 f1 2c cd fa eb 05 e8 ea 2c cd fa 4c 89 f0 48 c1 e8 03 <42> 80 3c 20 00 74 08 4c 89 f7 e8 24 aa 25 fb 4d 8b 36 4c 89 f7 e8 RSP: 0018:ffffc900046ff850 EFLAGS: 00010246 RAX: 0000000000000000 RBX: ffff88807ae4c050 RCX: ffff88807b2a8000 RDX: 0000000000000000 RSI: ffffffff8de003c0 RDI: 0000000000000001 RBP: ffff888025f12000 R08: ffff88807b2a8000 R09: 0000000000000004 R10: 0000000000000005 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000001 FS: 000055555eaa3500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3e60d87180 CR3: 000000002bdd7000 CR4: 00000000003506f0 ---------------- Code disassembly (best guess): 0: 41 83 ff 03 cmp $0x3,%r15d 4: 74 18 je 0x1e 6: 41 83 ff 05 cmp $0x5,%r15d a: 0f 85 8e 00 00 00 jne 0x9e 10: e8 f8 2c cd fa call 0xfacd2d0d 15: eb 0c jmp 0x23 17: e8 f1 2c cd fa call 0xfacd2d0d 1c: eb 05 jmp 0x23 1e: e8 ea 2c cd fa call 0xfacd2d0d 23: 4c 89 f0 mov %r14,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 20 00 cmpb $0x0,(%rax,%r12,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 4c 89 f7 mov %r14,%rdi 34: e8 24 aa 25 fb call 0xfb25aa5d 39: 4d 8b 36 mov (%r14),%r14 3c: 4c 89 f7 mov %r14,%rdi 3f: e8 .byte 0xe8