INFO: task syz-executor.3:31399 blocked for more than 143 seconds. Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. task:syz-executor.3 state:D stack:26720 pid:31399 ppid: 8502 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:4269 [inline] __schedule+0x890/0x2030 kernel/sched/core.c:5019 schedule+0xcf/0x270 kernel/sched/core.c:5098 io_uring_cancel_files fs/io_uring.c:8735 [inline] io_uring_cancel_task_requests fs/io_uring.c:8787 [inline] __io_uring_files_cancel+0xc4d/0x14b0 fs/io_uring.c:8883 io_uring_files_cancel include/linux/io_uring.h:51 [inline] exit_files+0xe4/0x170 fs/file.c:456 do_exit+0xb61/0x29f0 kernel/exit.c:818 do_group_exit+0x125/0x310 kernel/exit.c:920 get_signal+0x3ea/0x1f70 kernel/signal.c:2750 arch_do_signal_or_restart+0x2a6/0x1ea0 arch/x86/kernel/signal.c:811 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop kernel/entry/common.c:169 [inline] exit_to_user_mode_prepare+0x124/0x200 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x38/0x260 kernel/entry/common.c:274 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45deb9 Code: Unable to access opcode bytes at RIP 0x45de8f. RSP: 002b:00007effbe9c1cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 000000000118bf28 RCX: 000000000045deb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 000000000118bf28 RBP: 000000000118bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000118bf2c R13: 00007fffdd521bef R14: 00007effbe9c29c0 R15: 000000000118bf2c Showing all locks held in the system: 1 lock held by khungtaskd/1655: #0: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:6252 2 locks held by systemd-journal/4894: #0: ffff8880b9e34f98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1318 [inline] #0: ffff8880b9e34f98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x217/0x2030 kernel/sched/core.c:4936 #1: ffff8880b9e20088 (&per_cpu_ptr(group->pcpu, cpu)->seq){-.-.}-{0:0}, at: psi_task_switch+0x305/0x440 kernel/sched/psi.c:833 2 locks held by in:imklog/8174: #0: ffff88801499b270 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0xe9/0x100 fs/file.c:932 #1: ffff8880b9e34f98 (&rq->lock){-.-.}-{2:2}, at: rq_lock kernel/sched/sched.h:1318 [inline] #1: ffff8880b9e34f98 (&rq->lock){-.-.}-{2:2}, at: __schedule+0x217/0x2030 kernel/sched/core.c:4936 2 locks held by kworker/u4:6/10901: #0: ffff8880b9e34f98 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x789/0xe50 kernel/sched/fair.c:10622 #1: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: cpu_of kernel/sched/sched.h:1085 [inline] #1: ffffffff8b339ca0 (rcu_read_lock){....}-{1:2}, at: __update_idle_core+0x39/0x430 kernel/sched/fair.c:6039 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1655 Comm: khungtaskd Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:79 [inline] dump_stack+0x107/0x163 lib/dump_stack.c:120 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 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:338 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8 Comm: kworker/u4:0 Not tainted 5.10.0-rc4-next-20201120-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_iv_send_outstanding_bat_ogm_packet RIP: 0010:check_preemption_disabled+0x3f/0x130 lib/smp_processor_id.c:60 Code: 8b 25 c5 13 18 77 65 8b 1d 1e 6e 18 77 81 e3 ff ff ff 7f 31 ff 89 de 0f 1f 44 00 00 85 db 74 11 0f 1f 44 00 00 44 89 e0 5b 5d <41> 5c 41 5d 41 5e c3 0f 1f 44 00 00 9c 5b 81 e3 00 02 00 00 31 ff RSP: 0018:ffffc90000cd7a98 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffff888010d24f80 RCX: 1ffffffff1de9b44 RDX: 0000000000000000 RSI: 0000000000000200 RDI: 0000000000000000 RBP: 000000000152a5b6 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffffffff894b6c80 R14: ffff88802cefc0c8 R15: 0000000000001000 FS: 0000000000000000(0000) GS:ffff8880b9e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f69f09dd000 CR3: 000000001bec4000 CR4: 00000000001506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_finish kernel/locking/lockdep.c:435 [inline] lockdep_softirqs_on+0x221/0x340 kernel/locking/lockdep.c:4244 __local_bh_enable_ip+0xc9/0x110 kernel/softirq.c:183 local_bh_enable include/linux/bottom_half.h:32 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:733 [inline] __dev_queue_xmit+0x1b0b/0x2da0 net/core/dev.c:4167 batadv_send_skb_packet+0x4a9/0x5f0 net/batman-adv/send.c:108 batadv_iv_ogm_send_to_if net/batman-adv/bat_iv_ogm.c:394 [inline] batadv_iv_ogm_emit net/batman-adv/bat_iv_ogm.c:420 [inline] batadv_iv_send_outstanding_bat_ogm_packet+0x6ad/0x800 net/batman-adv/bat_iv_ogm.c:1712 process_one_work+0x933/0x15a0 kernel/workqueue.c:2272 worker_thread+0x64c/0x1120 kernel/workqueue.c:2418 kthread+0x3af/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296