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: 23645 Comm: syz.2.4687 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:set_link_state+0x27/0x1000 drivers/usb/gadget/udc/dummy_hcd.c:454 Code: 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 38 49 89 fe 48 bb 00 00 00 00 00 fc ff df e8 00 49 cb fa 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 f7 e8 1b cc 23 fb 49 8b 0e 4d 8d a6 93 00 RSP: 0018:ffffc900035a7a50 EFLAGS: 00010046 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc9000dd04000 RSI: 000000000000098d RDI: 000000000000098e RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520006b4f34 R12: 0000000000000a06 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f1ef24876c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1ef2486ff8 CR3: 0000000079f0e000 CR4: 00000000003506e0 Call Trace: dummy_pullup+0xc1/0x120 drivers/usb/gadget/udc/dummy_hcd.c:932 usb_gadget_disconnect_locked+0x120/0x440 drivers/usb/gadget/udc/core.c:782 gadget_unbind_driver+0xc2/0x3e0 drivers/usb/gadget/udc/core.c:1696 device_remove drivers/base/dd.c:626 [inline] __device_release_driver drivers/base/dd.c:1351 [inline] device_release_driver_internal+0x408/0x6f0 drivers/base/dd.c:1374 driver_detach+0x1f3/0x2d0 drivers/base/dd.c:1437 bus_remove_driver+0x221/0x2f0 drivers/base/bus.c:792 usb_gadget_unregister_driver+0x4e/0x70 drivers/usb/gadget/udc/core.c:1762 unregister_gadget drivers/usb/gadget/configfs.c:263 [inline] gadget_dev_desc_UDC_store+0x178/0x2e0 drivers/usb/gadget/configfs.c:290 flush_write_buffer fs/configfs/file.c:207 [inline] configfs_write_iter+0x312/0x400 fs/configfs/file.c:229 call_write_iter include/linux/fs.h:2018 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x474/0x9a0 fs/read_write.c:584 ksys_write+0x151/0x260 fs/read_write.c:637 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: 0033:0x7f1ef159e0d9 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f1ef2487028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f1ef1826090 RCX: 00007f1ef159e0d9 RDX: 0000000000000001 RSI: 00002000000004c0 RDI: 0000000000000005 RBP: 00007f1ef1635024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f1ef1826128 R14: 00007f1ef1826090 R15: 00007ffedaf5ff88 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:set_link_state+0x27/0x1000 drivers/usb/gadget/udc/dummy_hcd.c:454 Code: 0f 1f 00 55 41 57 41 56 41 55 41 54 53 48 83 ec 38 49 89 fe 48 bb 00 00 00 00 00 fc ff df e8 00 49 cb fa 4c 89 f0 48 c1 e8 03 <80> 3c 18 00 74 08 4c 89 f7 e8 1b cc 23 fb 49 8b 0e 4d 8d a6 93 00 RSP: 0018:ffffc900035a7a50 EFLAGS: 00010046 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: 0000000000080000 RDX: ffffc9000dd04000 RSI: 000000000000098d RDI: 000000000000098e RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff520006b4f34 R12: 0000000000000a06 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f1ef24876c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1ef2486ff8 CR3: 0000000079f0e000 CR4: 00000000003506e0 ---------------- Code disassembly (best guess): 0: 0f 1f 00 nopl (%rax) 3: 55 push %rbp 4: 41 57 push %r15 6: 41 56 push %r14 8: 41 55 push %r13 a: 41 54 push %r12 c: 53 push %rbx d: 48 83 ec 38 sub $0x38,%rsp 11: 49 89 fe mov %rdi,%r14 14: 48 bb 00 00 00 00 00 movabs $0xdffffc0000000000,%rbx 1b: fc ff df 1e: e8 00 49 cb fa call 0xfacb4923 23: 4c 89 f0 mov %r14,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) <-- trapping instruction 2e: 74 08 je 0x38 30: 4c 89 f7 mov %r14,%rdi 33: e8 1b cc 23 fb call 0xfb23cc53 38: 49 8b 0e mov (%r14),%rcx 3b: 4d rex.WRB 3c: 8d .byte 0x8d 3d: a6 cmpsb %es:(%rdi),%ds:(%rsi) 3e: 93 xchg %eax,%ebx