usb 1-1: USB disconnect, device number 2 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: 1 PID: 4471 Comm: syz.0.17 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:set_link_state+0x27/0x11d0 drivers/usb/gadget/udc/dummy_hcd.c:432 Code: ff ff 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 50 49 89 fe 48 bb 00 00 00 00 00 fc ff df e8 70 88 42 fb 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 f7 e8 1b ab 87 fb 4d 8b 26 4c 89 74 24 10 RSP: 0018:ffffc9000325f7c8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888074e6d940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200064bee8 R12: 0000000000000a02 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd6c17eae8 CR3: 000000002a3bb000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dummy_pullup+0xbd/0x120 drivers/usb/gadget/udc/dummy_hcd.c:911 usb_gadget_disconnect+0xd0/0x3a0 drivers/usb/gadget/udc/core.c:763 usb_gadget_remove_driver+0x4a/0x350 drivers/usb/gadget/udc/core.c:1491 usb_gadget_unregister_driver+0x15d/0x4c0 drivers/usb/gadget/udc/core.c:1654 raw_release+0xd6/0x260 drivers/usb/gadget/legacy/raw_gadget.c:416 __fput+0x212/0x8c0 fs/file_table.c:311 task_work_run+0x125/0x1a0 kernel/task_work.c:188 exit_task_work include/linux/task_work.h:33 [inline] do_exit+0x635/0x2110 kernel/exit.c:884 do_group_exit+0x12c/0x2f0 kernel/exit.c:998 get_signal+0x7eb/0x12e0 kernel/signal.c:2901 arch_do_signal_or_restart+0xe6/0x12a0 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f779c4bae99 Code: Unable to access opcode bytes at RIP 0x7f779c4bae6f. RSP: 002b:00007ffc97232ec8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: 000000000000000b RBX: 00007f779c742fa0 RCX: 00007f779c4bae99 RDX: 000000000000000b RSI: 0000200000000200 RDI: 0000000000000004 RBP: 00007f779c550eaf R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f779c742fac R14: 00007f779c742fa0 R15: 00007f779c742fa0 Modules linked in: ---[ end trace d042e4113dd2ddbd ]--- RIP: 0010:set_link_state+0x27/0x11d0 drivers/usb/gadget/udc/dummy_hcd.c:432 Code: ff ff 90 55 41 57 41 56 41 55 41 54 53 48 83 ec 50 49 89 fe 48 bb 00 00 00 00 00 fc ff df e8 70 88 42 fb 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 f7 e8 1b ab 87 fb 4d 8b 26 4c 89 74 24 10 RSP: 0018:ffffc9000325f7c8 EFLAGS: 00010046 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888074e6d940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff5200064bee8 R12: 0000000000000a02 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffd6c17eae8 CR3: 000000002a3bb000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess), 1 bytes skipped: 0: ff 90 55 41 57 41 call *0x41574155(%rax) 6: 56 push %rsi 7: 41 55 push %r13 9: 41 54 push %r12 b: 53 push %rbx c: 48 83 ec 50 sub $0x50,%rsp 10: 49 89 fe mov %rdi,%r14 13: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx 1a: fc ff df 1d: e8 70 88 42 fb call 0xfb428892 22: 4c 89 f0 mov %r14,%rax 25: 48 c1 e8 03 shr $0x3,%rax * 29: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction 2d: 74 08 je 0x37 2f: 4c 89 f7 mov %r14,%rdi 32: e8 1b ab 87 fb call 0xfb87ab52 37: 4d 8b 26 mov (%r14),%r12 3a: 4c 89 74 24 10 mov %r14,0x10(%rsp)