list_add double add: new=ffff88807982ef18, prev=ffff88807982ef18, next=ffff888038c56078. ------------[ cut here ]------------ kernel BUG at lib/list_debug.c:37! Oops: invalid opcode: 0000 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 17958 Comm: syz.5.3384 Tainted: G L syzkaller #0 PREEMPT_{RT,(full)} Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:__list_add_valid_or_report+0xa5/0x130 lib/list_debug.c:35 Code: 74 12 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d e9 92 9d 79 06 cc 48 c7 c7 60 5c ca 8b 4c 89 fe 4c 89 f2 48 89 d9 e8 fc ab 59 fc 90 <0f> 0b 48 c7 c7 40 5a ca 8b e8 ed ab 59 fc 90 0f 0b 48 c7 c7 00 5b RSP: 0018:ffffc900056b7320 EFLAGS: 00010246 RAX: 0000000000000058 RBX: ffff888038c56078 RCX: 168ed28160220d00 RDX: ffffc9001c38a000 RSI: 000000000000cc29 RDI: 000000000000cc2a RBP: 1ffff1100718ac10 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52000ad6e15 R12: 1ffff1100f305de3 R13: dffffc0000000000 R14: ffff88807982ef18 R15: ffff88807982ef18 FS: 00007f0c8e5d66c0(0000) GS:ffff888125d46000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa55f09b7c0 CR3: 000000007b5e2000 CR4: 00000000003526f0 Call Trace: __list_add_valid include/linux/list.h:96 [inline] __list_add include/linux/list.h:158 [inline] list_add_tail include/linux/list.h:191 [inline] usb_hcd_link_urb_to_ep+0x1d2/0x330 drivers/usb/core/hcd.c:1154 dummy_urb_enqueue+0x299/0x760 drivers/usb/gadget/udc/dummy_hcd.c:1310 usb_hcd_submit_urb+0x322/0x1b40 drivers/usb/core/hcd.c:1542 cm109_submit_buzz_toggle drivers/input/misc/cm109.c:351 [inline] cm109_toggle_buzzer_async drivers/input/misc/cm109.c:484 [inline] cm109_input_ev+0x1d1/0x3b0 drivers/input/misc/cm109.c:615 input_event_dispose+0x80/0x6b0 drivers/input/input.c:322 input_inject_event+0x1fa/0x310 drivers/input/input.c:424 kd_sound_helper+0x101/0x210 drivers/tty/vt/keyboard.c:257 input_handler_for_each_handle+0x101/0x1c0 drivers/input/input.c:2540 kd_mksound+0x96/0x130 drivers/tty/vt/keyboard.c:281 handle_ascii drivers/tty/vt/vt.c:2382 [inline] do_con_trol drivers/tty/vt/vt.c:2699 [inline] do_con_write+0x2f5a/0x5540 drivers/tty/vt/vt.c:3325 con_write+0x31/0x2e0 drivers/tty/vt/vt.c:3661 process_output_block drivers/tty/n_tty.c:557 [inline] n_tty_write+0xd4f/0x11e0 drivers/tty/n_tty.c:2366 iterate_tty_write drivers/tty/tty_io.c:1006 [inline] file_tty_write+0x50b/0x980 drivers/tty/tty_io.c:1081 new_sync_write fs/read_write.c:595 [inline] vfs_write+0x61e/0xbb0 fs/read_write.c:687 ksys_write+0x156/0x270 fs/read_write.c:739 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0c9037e0d9 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:00007f0c8e5d6028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f0c90605fa0 RCX: 00007f0c9037e0d9 RDX: 0000000000001006 RSI: 00002000000005c0 RDI: 000000000000000a RBP: 00007f0c90415024 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0c90606038 R14: 00007f0c90605fa0 R15: 00007ffe540fbc78 Modules linked in: ---[ end trace 0000000000000000 ]--- RIP: 0010:__list_add_valid_or_report+0xa5/0x130 lib/list_debug.c:35 Code: 74 12 b0 01 5b 41 5c 41 5d 41 5e 41 5f 5d e9 92 9d 79 06 cc 48 c7 c7 60 5c ca 8b 4c 89 fe 4c 89 f2 48 89 d9 e8 fc ab 59 fc 90 <0f> 0b 48 c7 c7 40 5a ca 8b e8 ed ab 59 fc 90 0f 0b 48 c7 c7 00 5b RSP: 0018:ffffc900056b7320 EFLAGS: 00010246 RAX: 0000000000000058 RBX: ffff888038c56078 RCX: 168ed28160220d00 RDX: ffffc9001c38a000 RSI: 000000000000cc29 RDI: 000000000000cc2a RBP: 1ffff1100718ac10 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: fffff52000ad6e15 R12: 1ffff1100f305de3 R13: dffffc0000000000 R14: ffff88807982ef18 R15: ffff88807982ef18 FS: 00007f0c8e5d66c0(0000) GS:ffff888125d46000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa55f09b7c0 CR3: 000000007b5e2000 CR4: 00000000003526f0