------------[ cut here ]------------ lockdep bfs error:-1 WARNING: CPU: 0 PID: 27700 at kernel/locking/lockdep.c:1960 print_bfs_bug+0x130/0x1e0 kernel/locking/lockdep.c:1960 Modules linked in: CPU: 0 PID: 27700 Comm: syz-executor.1 Not tainted 5.9.0-rc7-next-20200930-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 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:ffffc900091b6f40 EFLAGS: 00010082 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000040000 RSI: ffffffff815df1a5 RDI: fffff52001236dda RBP: 00000000ffffffff R08: 0000000000000001 R09: ffff8880ae420f8b R10: 0000000000000000 R11: 207065646b636f6c R12: ffff88802a4e0380 R13: dffffc0000000000 R14: 0000000000000003 R15: 0000000000000000 FS: 00007eff67223700(0000) GS:ffff8880ae400000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fca2e95bf80 CR3: 0000000099a57000 CR4: 00000000001526f0 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 alloc_object lib/debugobjects.c:239 [inline] __debug_object_init+0x5c6/0xd10 lib/debugobjects.c:548 debug_object_init lib/debugobjects.c:595 [inline] debug_object_activate+0x32c/0x3e0 lib/debugobjects.c:681 debug_rcu_head_queue kernel/rcu/rcu.h:176 [inline] __call_rcu kernel/rcu/tree.c:2943 [inline] call_rcu+0x2c/0x7d0 kernel/rcu/tree.c:3030 put_task_struct_rcu_user+0x7f/0xb0 kernel/exit.c:178 finish_task_switch+0x548/0x7a0 kernel/sched/core.c:3651 context_switch kernel/sched/core.c:3780 [inline] __schedule+0xecd/0x2200 kernel/sched/core.c:4526 preempt_schedule_irq+0xbf/0x1b0 kernel/sched/core.c:4787 irqentry_exit_cond_resched kernel/entry/common.c:358 [inline] irqentry_exit_cond_resched kernel/entry/common.c:350 [inline] irqentry_exit+0x65/0x90 kernel/entry/common.c:388 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:number+0x768/0xae0 lib/vsprintf.c:533 Code: 3e 11 9e fd 83 ed 01 31 ff 49 83 c4 01 89 ee 49 83 ed 01 e8 8a 0d 9e fd 83 fd ff 0f 85 6b ff ff ff 8b 44 24 04 4d 8d 64 07 01 <e8> 13 11 9e fd 31 ff 89 de 41 89 df e8 67 0d 9e fd 85 db 78 60 49 RSP: 0018:ffffc900091b7840 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00000000fffffffb RCX: ffffffff83d72386 RDX: 00000000ffffffff RSI: ffff88802a4e0380 RDI: 0000000000000005 RBP: 00000000ffffffff R08: 0000000000000010 R09: ffff88809b492059 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88809b49205b R13: ffffc900091b78d7 R14: ffff88809b493000 R15: ffff88809b49205a vsnprintf+0xf07/0x14f0 lib/vsprintf.c:2684 seq_vprintf fs/seq_file.c:379 [inline] seq_printf+0x195/0x240 fs/seq_file.c:394 proc_cgroupstats_show+0x152/0x230 kernel/cgroup/cgroup-v1.c:668 seq_read+0x432/0x1070 fs/seq_file.c:208 pde_read fs/proc/inode.c:321 [inline] proc_reg_read+0x221/0x300 fs/proc/inode.c:333 do_loop_readv_writev fs/read_write.c:751 [inline] do_loop_readv_writev fs/read_write.c:738 [inline] do_iter_read+0x48e/0x6e0 fs/read_write.c:793 vfs_readv+0xe5/0x150 fs/read_write.c:911 do_preadv fs/read_write.c:1003 [inline] __do_sys_preadv fs/read_write.c:1053 [inline] __se_sys_preadv fs/read_write.c:1048 [inline] __x64_sys_preadv+0x231/0x310 fs/read_write.c:1048 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45dd99 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007eff67222c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000127 RAX: ffffffffffffffda RBX: 0000000000025dc0 RCX: 000000000045dd99 RDX: 00000000000001a4 RSI: 00000000200017c0 RDI: 0000000000000005 RBP: 000000000118bf70 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007ffe1ccc49af R14: 00007eff672239c0 R15: 000000000118bf2c