------------[ cut here ]------------ lockdep bfs error:-1 WARNING: CPU: 1 PID: 27 at kernel/locking/lockdep.c:1960 print_bfs_bug+0x130/0x1e0 kernel/locking/lockdep.c:1960 Modules linked in: CPU: 1 PID: 27 Comm: kworker/u4:2 Not tainted 5.9.0-rc7-next-20200930-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: tc_filter_workqueue fl_uninit_mask_free_work RIP: 0010:print_bfs_bug+0x130/0x1e0 kernel/locking/lockdep.c:1960 Code: e2 08 00 74 2c 48 c7 c7 c0 7f a6 8d e8 49 51 01 00 66 90 85 db 75 05 5b 5d 41 5c c3 89 ee 48 c7 c7 20 e8 ab 88 e8 7b e5 c0 06 <0f> 0b 5b 5d 41 5c c3 0f 0b e8 62 82 e9 06 85 c0 74 d7 48 c7 c0 38 RSP: 0018:ffffc90000e37690 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: ffff8880a90e8140 RSI: ffffffff815df1a5 RDI: fffff520001c6ec4 RBP: 00000000ffffffff R08: 0000000000000001 R09: ffff8880ae520f8b R10: 0000000000000000 R11: 207065646b636f6c R12: ffff8880a90e8140 R13: dffffc0000000000 R14: 0000000000000003 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8880ae500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000749698 CR3: 0000000085500000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: check_irq_usage+0x6b4/0xc60 kernel/locking/lockdep.c:2585 check_prev_add kernel/locking/lockdep.c:2823 [inline] check_prevs_add kernel/locking/lockdep.c:2944 [inline] validate_chain kernel/locking/lockdep.c:3562 [inline] __lock_acquire+0x2873/0x56d0 kernel/locking/lockdep.c:4796 lock_acquire+0x1f2/0xaa0 kernel/locking/lockdep.c:5398 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 __free_object+0x2c0/0xf10 lib/debugobjects.c:376 __debug_check_no_obj_freed lib/debugobjects.c:973 [inline] debug_check_no_obj_freed+0x1c4/0x420 lib/debugobjects.c:998 kfree+0xfb/0x2a0 mm/slab.c:3757 process_one_work+0x933/0x15a0 kernel/workqueue.c:2269 worker_thread+0x64c/0x1120 kernel/workqueue.c:2415 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296