INFO: task syz-executor.4:32186 blocked for more than 143 seconds. Not tainted 6.3.0-rc2-next-20230317-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.4 state:D stack:27536 pid:32186 ppid:32143 flags:0x00004006 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 get_signal+0x1c7/0x25b0 kernel/signal.c:2635 arch_do_signal_or_restart+0x79/0x5c0 arch/x86/kernel/signal.c:306 exit_to_user_mode_loop kernel/entry/common.c:168 [inline] exit_to_user_mode_prepare+0x11f/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: 0033:0x7efc8888c0f9 RSP: 002b:00007efc896bc168 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: 000000000000000b RBX: 00007efc889abf80 RCX: 00007efc8888c0f9 RDX: 0000000000000318 RSI: 00000000200bd000 RDI: 0000000000000004 RBP: 00007efc888e7b39 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ffc14f8321f R14: 00007efc896bc300 R15: 0000000000022000 Showing all locks held in the system: 1 lock held by rcu_tasks_kthre/13: #0: ffffffff8c795830 (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: ffffffff8c795530 (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: ffffffff8c796400 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x51/0x390 kernel/locking/lockdep.c:6545 2 locks held by getty/4763: #0: ffff88814a9d6098 (&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:2177 1 lock held by syz-executor.0/5101: #0: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:325 [inline] #0: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x3e8/0x770 kernel/rcu/tree_exp.h:992 1 lock held by syz-executor.2/32139: #0: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: exp_funnel_lock kernel/rcu/tree_exp.h:293 [inline] #0: ffffffff8c7a1878 (rcu_state.exp_mutex){+.+.}-{3:3}, at: synchronize_rcu_expedited+0x64a/0x770 kernel/rcu/tree_exp.h:992 1 lock held by syz-executor.4/32186: #0: ffff888089deb068 (&ep->mtx){+.+.}-{3:3}, at: eventpoll_release_file+0xe2/0x1d0 fs/eventpoll.c:962 1 lock held by syz-executor.4/32188: 2 locks held by kworker/u4:5/32211: 2 locks held by kworker/1:4/32419: #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: arch_atomic_long_set include/linux/atomic/atomic-long.h:41 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: atomic_long_set include/linux/atomic/atomic-instrumented.h:1280 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:639 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:666 [inline] #0: ffff888012472538 ((wq_completion)rcu_gp){+.+.}-{0:0}, at: process_one_work+0x87a/0x15c0 kernel/workqueue.c:2361 #1: ffffc900105d7da8 ((work_completion)(&rew->rew_work)){+.+.}-{0:0}, at: process_one_work+0x8ae/0x15c0 kernel/workqueue.c:2365 2 locks held by syz-executor.2/388: 2 locks held by syz-executor.2/393: 3 locks held by syz-executor.2/400: 2 locks held by syz-executor.5/490: 1 lock held by syz-executor.3/508: #0: ffffffff8c7a1740 (rcu_state.barrier_mutex){+.+.}-{3:3}, at: rcu_barrier+0x48/0x6a0 kernel/rcu/tree.c:3950 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 28 Comm: khungtaskd Not tainted 6.3.0-rc2-next-20230317-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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 32211 Comm: kworker/u4:5 Not tainted 6.3.0-rc2-next-20230317-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/02/2023 Workqueue: bat_events batadv_nc_worker RIP: 0010:__this_cpu_preempt_check+0x11/0x20 lib/smp_processor_id.c:66 Code: 00 00 48 c7 c6 00 e5 a6 8a 48 c7 c7 40 e5 a6 8a e9 74 fe ff ff 0f 1f 40 00 f3 0f 1e fa 55 48 89 fd 0f 1f 44 00 00 48 89 ee 5d <48> c7 c7 80 e5 a6 8a e9 53 fe ff ff 0f 1f 00 41 57 41 56 41 55 41 RSP: 0018:ffffc9000c52fb48 EFLAGS: 00000046 RAX: 0000000000000002 RBX: 4503ee5c38b2b75f RCX: ffffc9000c52fba0 RDX: 1ffff11004afd895 RSI: ffffffff8a4c6040 RDI: ffffffff8a4c6040 RBP: 1ffff920018a5f6c R08: 0000000000000001 R09: ffffffff8e7844d7 R10: fffffbfff1cf089a R11: 0000000000000000 R12: 0000000000000002 R13: ffff8880257ec4b0 R14: 0000000000000003 R15: ffff8880257eba80 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c00acf5000 CR3: 0000000026e1b000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:467 [inline] lock_release+0x3be/0x670 kernel/locking/lockdep.c:5713 rcu_lock_release include/linux/rcupdate.h:332 [inline] rcu_read_unlock include/linux/rcupdate.h:806 [inline] batadv_nc_process_nc_paths.part.0+0x234/0x3f0 net/batman-adv/network-coding.c:699 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:679 [inline] batadv_nc_worker+0xd20/0xfe0 net/batman-adv/network-coding.c:735 process_one_work+0x991/0x15c0 kernel/workqueue.c:2390 worker_thread+0x669/0x1090 kernel/workqueue.c:2537 kthread+0x33e/0x440 kernel/kthread.c:379 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308