------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: lib/refcount.c:28 at refcount_warn_saturate+0x11a/0x1d0 lib/refcount.c:28, CPU#0: kworker/0:0/9 Modules linked in: CPU: 0 UID: 0 PID: 9 Comm: kworker/0:0 Not tainted 6.16.0-next-20250731-syzkaller #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: e0 bb e2 8b e8 c7 06 bb fc 90 0f 0b 90 90 eb d7 e8 cb 6f f7 fc c6 05 78 cd c3 0a 01 90 48 c7 c7 40 bc e2 8b e8 a7 06 bb fc 90 <0f> 0b 90 90 eb b7 e8 ab 6f f7 fc c6 05 55 cd c3 0a 01 90 48 c7 c7 RSP: 0018:ffffc900000e7a68 EFLAGS: 00010246 RAX: fe9aa72304599700 RBX: 0000000000000003 RCX: ffff88801cea8000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000002 RBP: ffffc900000e7c70 R08: ffff8880b8624253 R09: 1ffff110170c484a R10: dffffc0000000000 R11: ffffed10170c484b R12: ffff8880b86396c0 R13: ffff88801cae4918 R14: ffff8880547ca130 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125c43000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000557079ef2950 CR3: 0000000061540000 CR4: 00000000003526f0 Call Trace: process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xade/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/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