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: 1 PID: 1643 Comm: syz.6.515 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:dummy_udc_stop+0x7e/0x330 drivers/usb/gadget/udc/dummy_hcd.c:1031 Code: 4d 8d bc c7 d0 04 00 00 4c 89 f8 48 c1 e8 03 80 3c 18 00 49 89 de 74 08 4c 89 ff e8 0c 7d 7f fe 49 8b 1f 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 f3 7c 7f fe 48 8b 1b 48 89 df e8 RSP: 0018:ffffc90000b27958 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88811134e2c0 RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000005 RBP: ffffc90000b279b0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000164f10 R12: ffff8881019b4c90 R13: ffffffff857c2588 R14: dffffc0000000000 R15: ffff8881019b5160 FS: 00007ff4d876e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2b7bfe CR3: 000000013af82000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: usb_gadget_udc_stop drivers/usb/gadget/udc/core.c:1147 [inline] usb_gadget_remove_driver+0x1ee/0x310 drivers/usb/gadget/udc/core.c:1441 usb_del_gadget+0x180/0x290 drivers/usb/gadget/udc/core.c:1472 usb_del_gadget_udc+0x15/0x30 drivers/usb/gadget/udc/core.c:1492 dummy_udc_remove+0x58/0x60 drivers/usb/gadget/udc/dummy_hcd.c:1120 platform_remove+0x63/0xb0 drivers/base/platform.c:1411 __device_release_driver drivers/base/dd.c:1227 [inline] device_release_driver_internal+0x4e8/0x7c0 drivers/base/dd.c:1262 device_driver_detach+0x3b/0x40 drivers/base/dd.c:1298 unbind_store+0x2e5/0x300 drivers/base/bus.c:193 drv_attr_store+0x79/0xa0 drivers/base/bus.c:77 sysfs_kf_write+0x129/0x150 fs/sysfs/file.c:139 kernfs_fop_write_iter+0x2bd/0x400 fs/kernfs/file.c:296 call_write_iter include/linux/fs.h:2212 [inline] new_sync_write fs/read_write.c:507 [inline] vfs_write+0x831/0xfd0 fs/read_write.c:594 ksys_write+0x14a/0x260 fs/read_write.c:647 __do_sys_write fs/read_write.c:659 [inline] __se_sys_write fs/read_write.c:656 [inline] __x64_sys_write+0x7b/0x90 fs/read_write.c:656 x64_sys_call+0x8ef/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:2 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7ff4d9d14f99 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:00007ff4d876e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007ff4d9f9cfa0 RCX: 00007ff4d9d14f99 RDX: 000000000000000c RSI: 0000200000000a00 RDI: 0000000000000003 RBP: 00007ff4d9dabec4 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff4d9f9d038 R14: 00007ff4d9f9cfa0 R15: 00007ffcf830a038 Modules linked in: ---[ end trace b200a02f24fe43c2 ]--- RIP: 0010:dummy_udc_stop+0x7e/0x330 drivers/usb/gadget/udc/dummy_hcd.c:1031 Code: 4d 8d bc c7 d0 04 00 00 4c 89 f8 48 c1 e8 03 80 3c 18 00 49 89 de 74 08 4c 89 ff e8 0c 7d 7f fe 49 8b 1f 48 89 d8 48 c1 e8 03 <42> 80 3c 30 00 74 08 48 89 df e8 f3 7c 7f fe 48 8b 1b 48 89 df e8 RSP: 0018:ffffc90000b27958 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff88811134e2c0 RDX: 0000000000000002 RSI: 0000000000000003 RDI: 0000000000000005 RBP: ffffc90000b279b0 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000164f10 R12: ffff8881019b4c90 R13: ffffffff857c2588 R14: dffffc0000000000 R15: ffff8881019b5160 FS: 00007ff4d876e6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9810a3b4b8 CR3: 000000013af82000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: 4d 8d bc c7 d0 04 00 lea 0x4d0(%r15,%rax,8),%r15 7: 00 8: 4c 89 f8 mov %r15,%rax b: 48 c1 e8 03 shr $0x3,%rax f: 80 3c 18 00 cmpb $0x0,(%rax,%rbx,1) 13: 49 89 de mov %rbx,%r14 16: 74 08 je 0x20 18: 4c 89 ff mov %r15,%rdi 1b: e8 0c 7d 7f fe call 0xfe7f7d2c 20: 49 8b 1f mov (%r15),%rbx 23: 48 89 d8 mov %rbx,%rax 26: 48 c1 e8 03 shr $0x3,%rax * 2a: 42 80 3c 30 00 cmpb $0x0,(%rax,%r14,1) <-- trapping instruction 2f: 74 08 je 0x39 31: 48 89 df mov %rbx,%rdi 34: e8 f3 7c 7f fe call 0xfe7f7d2c 39: 48 8b 1b mov (%rbx),%rbx 3c: 48 89 df mov %rbx,%rdi 3f: e8 .byte 0xe8