INFO: task syz-executor.2:20259 blocked for more than 143 seconds. Not tainted 5.6.0-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.2 D28160 20259 7284 0x00004004 Call Trace: context_switch kernel/sched/core.c:3378 [inline] __schedule+0x805/0xc90 kernel/sched/core.c:4094 schedule+0x188/0x220 kernel/sched/core.c:4168 schedule_timeout+0x43/0x250 kernel/time/timer.c:1874 pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:650 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:55 [inline] do_raw_spin_unlock+0x134/0x8d0 kernel/locking/spinlock_debug.c:139 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 do_wait_for_common+0x232/0x370 kernel/sched/completion.c:85 console_conditional_schedule+0x30/0x30 __wait_for_common kernel/sched/completion.c:106 [inline] wait_for_common kernel/sched/completion.c:117 [inline] wait_for_completion+0x43/0x50 kernel/sched/completion.c:138 rdma_destroy_id+0xdea/0x1140 drivers/infiniband/core/cma.c:1850 pv_queued_spin_unlock arch/x86/include/asm/paravirt.h:650 [inline] queued_spin_unlock arch/x86/include/asm/qspinlock.h:55 [inline] do_raw_spin_unlock+0x134/0x8d0 kernel/locking/spinlock_debug.c:139 __raw_spin_unlock_irq include/linux/spinlock_api_smp.h:168 [inline] _raw_spin_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:199 ucma_close+0x1d8/0x2b0 drivers/infiniband/core/ucma.c:1762 ucma_open+0x1f0/0x1f0 drivers/infiniband/core/ucma.c:1736 __fput+0x2de/0x730 fs/file_table.c:280 task_work_run+0x147/0x1d0 kernel/task_work.c:123 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop arch/x86/entry/common.c:165 [inline] prepare_exit_to_usermode+0x48e/0x600 arch/x86/entry/common.c:196 syscall_return_slowpath+0xf9/0x420 arch/x86/entry/common.c:278 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1136: #0: ffffffff890e6710 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 lib/xarray.c:75 3 locks held by kworker/u4:5/2762: #0: ffff8880ae9374d8 (&rq->lock){-.-.}-{2:2}, at: newidle_balance+0x664/0xb20 kernel/sched/fair.c:10516 #1: ffffffff890e6710 (rcu_read_lock){....}-{1:2}, at: rcu_lock_acquire+0x0/0x30 lib/xarray.c:75 #2: ffff8880ae927418 (&base->lock){-.-.}-{2:2}, at: lock_timer_base kernel/time/timer.c:936 [inline] #2: ffff8880ae927418 (&base->lock){-.-.}-{2:2}, at: __mod_timer+0x1e3/0x15e0 kernel/time/timer.c:1009 1 lock held by in:imklog/6673: #0: ffff88809ec34130 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x25d/0x2f0 fs/file.c:826 2 locks held by agetty/6707: #0: ffff8880953f0098 (&tty->ldisc_sem){++++}-{0:0}, at: tty_ldisc_ref_wait+0x21/0x70 drivers/tty/tty_ldisc.c:267 #1: ffffc900011542e8 (&ldata->atomic_read_lock){+.+.}-{3:3}, at: n_tty_read+0x260/0x1bc0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1136 Comm: khungtaskd Not tainted 5.6.0-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+0x1e9/0x30e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 arch_trigger_cpumask_backtrace+0x10/0x10 arch/x86/kernel/apic/hw_nmi.c:38 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xd2a/0xd40 kernel/hung_task.c:289 kthread+0x353/0x380 kernel/kthread.c:268 hungtask_pm_notify+0x50/0x50 kernel/hung_task.c:265 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 2762 Comm: kworker/u4:5 Not tainted 5.6.0-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:__lock_acquire+0xbe1/0x2b90 kernel/locking/lockdep.c:4314 Code: 0c 00 00 48 c7 c0 b0 40 31 8b 48 c1 e8 03 48 bf 00 00 00 00 00 fc ff df 8a 04 38 84 c0 0f 85 26 10 00 00 83 3d 7f c1 d6 09 00 <75> 3e 4c 63 7c 24 50 49 8d 47 3f 4d 85 ff 49 0f 49 c7 48 c1 f8 06 RSP: 0018:ffffc90008447a40 EFLAGS: 00000046 RAX: 1ffffffff1662800 RBX: ffff88809f81e300 RCX: ffffffff815aea12 RDX: 0000000000000000 RSI: 0000000000000008 RDI: dffffc0000000000 RBP: ffffc90008447bb0 R08: dffffc0000000000 R09: fffffbfff15e0d0f R10: fffffbfff15e0d0f R11: 0000000000000000 R12: ffff88809f81ec30 R13: 1ffff11013f03d86 R14: ffff88809f81ec10 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa8e3781000 CR3: 00000000a7a98000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 000000000000005e DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x169/0x480 kernel/locking/lockdep.c:4923 rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:207 rcu_lock_release+0x5/0x20 include/linux/rcupdate.h:212 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:208 rcu_lock_acquire+0x5/0x30 include/linux/rcupdate.h:207 rcu_read_lock include/linux/rcupdate.h:601 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:407 [inline] batadv_nc_worker+0xc8/0x5e0 net/batman-adv/network-coding.c:718 lock_is_held include/linux/lockdep.h:406 [inline] rcu_read_lock_sched_held+0x106/0x170 kernel/rcu/update.c:121 process_one_work+0x76e/0xfd0 kernel/workqueue.c:2266 worker_thread+0xa7f/0x1450 kernel/workqueue.c:2412 kthread+0x353/0x380 kernel/kthread.c:268 rcu_lock_release+0x20/0x20 kthread_blkcg+0xd0/0xd0 kernel/kthread.c:1247 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352