------------[ cut here ]------------ refcount_t: underflow; use-after-free. WARNING: CPU: 0 PID: 28084 at lib/refcount.c:28 refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Kernel panic - not syncing: panic_on_warn set ... CPU: 0 PID: 28084 Comm: io_wqe_worker-1 Not tainted 5.9.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1d6/0x29e lib/dump_stack.c:118 panic+0x2c0/0x800 kernel/panic.c:231 __warn+0x227/0x250 kernel/panic.c:600 report_bug+0x1b1/0x2e0 lib/bug.c:198 handle_bug+0x42/0x80 arch/x86/kernel/traps.c:234 exc_invalid_op+0x16/0x40 arch/x86/kernel/traps.c:254 asm_exc_invalid_op+0x12/0x20 arch/x86/include/asm/idtentry.h:536 RIP: 0010:refcount_warn_saturate+0x15b/0x1a0 lib/refcount.c:28 Code: c7 3a 98 15 89 31 c0 e8 43 21 a6 fd 0f 0b eb 85 e8 aa 82 d4 fd c6 05 16 6b ea 05 01 48 c7 c7 66 98 15 89 31 c0 e8 25 21 a6 fd <0f> 0b e9 64 ff ff ff e8 89 82 d4 fd c6 05 f6 6a ea 05 01 48 c7 c7 RSP: 0018:ffffc90016067db8 EFLAGS: 00010246 RAX: 900a2fa84b7a7100 RBX: 0000000000000003 RCX: ffff8880a2912300 RDX: 0000000000000000 RSI: 0000000080000000 RDI: 0000000000000000 RBP: 0000000000000003 R08: ffffffff815e3810 R09: ffffed1015d062c0 R10: ffffed1015d062c0 R11: 0000000000000000 R12: ffff8880916eb0b8 R13: dffffc0000000000 R14: ffff8880a9a17000 R15: ffff8880a7b44930 refcount_sub_and_test include/linux/refcount.h:274 [inline] refcount_dec_and_test include/linux/refcount.h:294 [inline] io_worker_exit+0x63f/0x750 fs/io-wq.c:236 io_wqe_worker+0x799/0x810 fs/io-wq.c:596 kthread+0x37e/0x3a0 drivers/block/aoe/aoecmd.c:1234 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Kernel Offset: disabled Rebooting in 86400 seconds..