hub 9-1:4.0: hub_ext_port_status failed (err = -71) ------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 1 PID: 18276 at lib/refcount.c:28 refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28 Modules linked in: CPU: 1 UID: 0 PID: 18276 Comm: kworker/1:0 Not tainted 6.16.0-syzkaller-11743-g6bcdbd62bd56 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: md_misc mddev_delayed_delete RIP: 0010:refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28 Code: 20 a1 e2 8b e8 67 05 bc fc 90 0f 0b 90 90 eb d7 e8 db 66 f8 fc c6 05 7e f1 c5 0a 01 90 48 c7 c7 80 a1 e2 8b e8 47 05 bc fc 90 <0f> 0b 90 90 eb b7 e8 bb 66 f8 fc c6 05 5b f1 c5 0a 01 90 48 c7 c7 RSP: 0018:ffffc9000e9afa68 EFLAGS: 00010246 RAX: 1acf66bb752b8b00 RBX: 0000000000000003 RCX: ffff88801d2a0000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: ffffc9000e9afc70 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff1bfa1ec R12: ffff8880b8739700 R13: ffff88805a1d8118 R14: ffff88806d350130 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125d24000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c30df11 CR3: 0000000077e35000 CR4: 0000000000350ef0 Call Trace: process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245