INFO: task syz-executor.0:8523 blocked for more than 143 seconds. Not tainted 6.3.0-rc3-next-20230320-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.0 state:D stack:28000 pid:8523 ppid:5124 flags:0x00004004 Call Trace: context_switch kernel/sched/core.c:5305 [inline] __schedule+0x1d23/0x5650 kernel/sched/core.c:6623 schedule+0xde/0x1a0 kernel/sched/core.c:6699 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:6758 __mutex_lock_common kernel/locking/mutex.c:679 [inline] __mutex_lock+0xa3b/0x1350 kernel/locking/mutex.c:747 eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962 eventpoll_release include/linux/eventpoll.h:53 [inline] __fput+0x7da/0xa90 fs/file_table.c:312 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f7eeb68c0f9 RSP: 002b:00007f7eec3c3168 EFLAGS: 00000246 ORIG_RAX: 00000000000001b4 RAX: 0000000000000000 RBX: 00007f7eeb7abf80 RCX: 00007f7eeb68c0f9 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 0000000000000003 RBP: 00007f7eeb6e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffcc795cf3f R14: 00007f7eec3c3300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c795870 (rcu_tasks.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516 1 lock held by rcu_tasks_trace/14: #0: ffffffff8c795570 (rcu_tasks_trace.tasks_gp_mutex){+.+.}-{3:3}, at: rcu_tasks_one_gp+0x31/0xd80 kernel/rcu/tasks.h:516 1 lock held by khungtaskd/28: #0: ffffffff8c796440 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6545 2 locks held by getty/4761: #0: ffff888027c3c098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x26/0x80 drivers/tty/tty_ldisc.c:243 #1: ffffc900015a02f0 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0xef4/0x13e0 drivers/tty/n_tty.c:2176 3 locks held by kworker/u4:14/5522: 1 lock held by syz-executor.0/8523: #0: ffff88807ce02868 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962 1 lock held by syz-executor.0/8528: 1 lock held by syz-executor.1/8686: 1 lock held by syz-executor.1/8690: #0: ffff888028f9b468 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962 1 lock held by syz-executor.1/8764: 1 lock held by syz-executor.1/8765: #0: ffff888022d6a468 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc3-next-20230320-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Call Trace: __dump_stack lib/dump_stack.c:88 [inline] dump_stack_lvl+0xd9/0x150 lib/dump_stack.c:106 nmi_cpu_backtrace+0x29c/0x350 lib/nmi_backtrace.c:113 nmi_trigger_cpumask_backtrace+0x2a4/0x300 lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:148 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:222 [inline] watchdog+0xe16/0x1090 kernel/hung_task.c:379 kthread+0x33e/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8764 Comm: syz-executor.1 Not tainted 6.3.0-rc3-next-20230320-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:68 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:hlock_class kernel/locking/lockdep.c:228 [inline] RIP: 0010:__lock_acquire+0x171a/0x5df0 kernel/locking/lockdep.c:5070 Code: 3c 03 0f 8e a1 39 00 00 41 0f b7 5c 24 f8 66 81 e3 ff 1f 0f b7 db be 08 00 00 00 48 89 d8 48 c1 e8 06 48 8d 3c c5 00 2c 4f 91 61 e3 70 00 48 0f a3 1d 59 c8 ea 0f 0f 83 51 06 00 00 48 8d 1c RSP: 0018:ffffc90004f2fae0 EFLAGS: 00000003 RAX: 0000000000000015 RBX: 0000000000000578 RCX: ffffffff81645b87 RDX: 1ffff110041e54f3 RSI: 0000000000000008 RDI: ffffffff914f2ca8 RBP: 0000000000000005 R08: 0000000000000000 R09: ffffffff914f2ca7 R10: fffffbfff229e594 R11: 0000000000000000 R12: ffff888020f2a7a0 R13: ffff888020f29d40 R14: 0000000000000000 R15: b141bec50ee5f908 FS: 00007f37123fe700(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c000679b97 CR3: 000000007cf3c000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire.part.0+0x11c/0x370 kernel/locking/lockdep.c:5691 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:350 [inline] __ep_remove+0x13c/0xa50 fs/eventpoll.c:735 ep_remove_safe fs/eventpoll.c:782 [inline] ep_clear_and_put+0x21c/0x3b0 fs/eventpoll.c:815 ep_eventpoll_release+0x45/0x60 fs/eventpoll.c:831 __fput+0x27c/0xa90 fs/file_table.c:321 task_work_run+0x16f/0x270 kernel/task_work.c:179 resume_user_mode_work include/linux/resume_user_mode.h:49 [inline] exit_to_user_mode_loop kernel/entry/common.c:171 [inline] exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204 __syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline] syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86 entry_SYSCALL_64_after_hwframe+0x63/0xcd RIP: 0033:0x7f371388c0f9 Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 f1 19 00 00 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 73 01 c3 48 c7 c1 b8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f37123fe168 EFLAGS: 00000246 ORIG_RAX: 00000000000001b9 RAX: 0000000000000000 RBX: 00007f37139abf80 RCX: 00007f371388c0f9 RDX: 0000000000000001 RSI: 0000000020000180 RDI: 0000000000000004 RBP: 00007f37138e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000020000080 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc249ff08f R14: 00007f37123fe300 R15: 0000000000022000