INFO: task syz-executor113:9225 blocked for more than 143 seconds. Not tainted 5.8.0-next-20200812-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor113 D28360 9225 6830 0x80000000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 io_uring_cancel_files fs/io_uring.c:7897 [inline] io_uring_flush+0x740/0xa90 fs/io_uring.c:7914 filp_close+0xb4/0x170 fs/open.c:1276 close_files fs/file.c:401 [inline] put_files_struct fs/file.c:429 [inline] put_files_struct+0x1cc/0x350 fs/file.c:426 exit_files+0x7e/0xa0 fs/file.c:458 do_exit+0xb43/0x29f0 kernel/exit.c:801 do_group_exit+0x125/0x310 kernel/exit.c:903 __do_sys_exit_group kernel/exit.c:914 [inline] __se_sys_exit_group kernel/exit.c:912 [inline] __x64_sys_exit_group+0x3a/0x50 kernel/exit.c:912 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x440938 Code: Bad RIP value. RSP: 002b:00007ffe99d95358 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000440938 RDX: 0000000000000000 RSI: 000000000000003c RDI: 0000000000000000 RBP: 00000000004c01d0 R08: 00000000000000e7 R09: ffffffffffffffd0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000006d21a0 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 1 lock held by khungtaskd/1165: #0: ffffffff89c66c40 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5825 1 lock held by in:imklog/6533: #0: ffff8880a6503bb0 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:930 4 locks held by kworker/1:1/6848: #0: ffff8880ae735e18 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x77f/0xe30 kernel/sched/fair.c:10555 #1: ffffffff89c66c40 (rcu_read_lock){....}-{1:2}, at: cpu_of kernel/sched/sched.h:1072 [inline] #1: ffffffff89c66c40 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x39/0x3e0 kernel/sched/fair.c:6014 #2: ffff8880ae726698 (&base->lock){..-.}-{2:2}, at: lock_timer_base+0x55/0x1a0 kernel/time/timer.c:947 #3: ffffffff8cd18710 (&obj_hash[i].lock){-.-.}-{2:2}, at: debug_object_activate+0x12e/0x3e0 lib/debugobjects.c:636 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1165 Comm: khungtaskd Not tainted 5.8.0-next-20200812-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:147 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:253 [inline] watchdog+0xd89/0xf30 kernel/hung_task.c:339 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 3895 Comm: systemd-journal Not tainted 5.8.0-next-20200812-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:91 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:108 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:134 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:165 [inline] RIP: 0010:check_memory_region_inline mm/kasan/generic.c:183 [inline] RIP: 0010:check_memory_region+0xde/0x180 mm/kasan/generic.c:192 Code: 74 f2 48 89 c2 b8 01 00 00 00 48 85 d2 75 56 5b 5d 41 5c c3 48 85 d2 74 5e 48 01 ea eb 09 48 83 c0 01 48 39 d0 74 50 80 38 00 <74> f2 eb d4 41 bc 08 00 00 00 48 89 ea 45 29 dc 4d 8d 1c 2c eb 0c RSP: 0018:ffffc90005637b00 EFLAGS: 00000046 RAX: fffffbfff18d173c RBX: fffffbfff18d173d RCX: ffffffff815a0170 RDX: fffffbfff18d173d RSI: 0000000000000008 RDI: ffffffff8c68b9e0 RBP: fffffbfff18d173c R08: 0000000000000000 R09: ffffffff8c68b9e7 R10: fffffbfff18d173c R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: ffff88809322e240 R15: 0000000000000000 FS: 00007fd2476908c0(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd244a2e000 CR3: 00000000930f5000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: instrument_atomic_read include/linux/instrumented.h:56 [inline] test_bit include/asm-generic/bitops/instrumented-non-atomic.h:110 [inline] hlock_class kernel/locking/lockdep.c:179 [inline] check_wait_context kernel/locking/lockdep.c:4101 [inline] __lock_acquire+0x480/0x5640 kernel/locking/lockdep.c:4376 lock_acquire+0x1f1/0xad0 kernel/locking/lockdep.c:5005 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x8c/0xc0 kernel/locking/spinlock.c:159 debug_object_active_state lib/debugobjects.c:902 [inline] debug_object_active_state+0x10b/0x350 lib/debugobjects.c:889 debug_rcu_head_queue kernel/rcu/rcu.h:177 [inline] __call_rcu kernel/rcu/tree.c:2880 [inline] call_rcu+0x44/0x7e0 kernel/rcu/tree.c:2968 task_work_run+0xdd/0x190 kernel/task_work.c:135 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_user_mode_loop kernel/entry/common.c:139 [inline] exit_to_user_mode_prepare+0x195/0x1c0 kernel/entry/common.c:166 syscall_exit_to_user_mode+0x59/0x2b0 kernel/entry/common.c:241 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x7fd246c20840 Code: 73 01 c3 48 8b 0d 68 77 20 00 f7 d8 64 89 01 48 83 c8 ff c3 66 0f 1f 44 00 00 83 3d 89 bb 20 00 00 75 10 b8 02 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 1e f6 ff ff 48 89 04 24 RSP: 002b:00007ffe257d5e88 EFLAGS: 00000246 ORIG_RAX: 0000000000000002 RAX: fffffffffffffffe RBX: 00007ffe257d6190 RCX: 00007fd246c20840 RDX: 00000000000001a0 RSI: 0000000000080042 RDI: 00005605eca8b7c0 RBP: 000000000000000d R08: 00000000000001c0 R09: 00000000ffffffff R10: 0000000000000040 R11: 0000000000000246 R12: 00000000ffffffff R13: 00005605eca87040 R14: 00007ffe257d6150 R15: 00005605eca946b0