INFO: task syz-executor.4:13129 blocked for more than 143 seconds. Not tainted 5.7.0-rc6-syzkaller #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D26408 13129 7405 0x80004006 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 __sched_text_start+0x8/0x8 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:694 [inline] queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] do_raw_spin_lock+0x129/0x2e0 kernel/locking/spinlock_debug.c:113 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1329 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 rwsem_down_write_slowpath+0x706/0xf90 kernel/locking/rwsem.c:1235 rwsem_mark_wake+0x8d0/0x8d0 include/linux/compiler.h:199 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 inode_lock include/linux/fs.h:797 [inline] __sock_release+0x86/0x280 net/socket.c:604 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 __down_timeout+0x2d0/0x2d0 trace_hardirqs_on+0x55/0x220 kernel/trace/trace_preemptirq.c:31 unregister_netdevice_notifier+0x1e/0x170 net/core/dev.c:1776 bcm_release+0x8b/0x660 net/can/bcm.c:1474 __sock_release+0x280/0x280 net/socket.c:605 __sock_release+0xcd/0x280 net/socket.c:605 sock_close+0x18/0x20 net/socket.c:1283 __fput+0x33e/0x880 fs/file_table.c:280 task_work_run+0xf4/0x1b0 kernel/task_work.c:123 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0xb34/0x2dd0 kernel/exit.c:796 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 mm_update_next_owner+0x7a0/0x7a0 kernel/exit.c:375 apparmor_file_alloc_security+0x333/0xb10 security/apparmor/lsm.c:444 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:694 [inline] queued_spin_lock include/asm-generic/qspinlock.h:78 [inline] do_raw_spin_lock+0x129/0x2e0 kernel/locking/spinlock_debug.c:113 rwlock_bug.part.0+0x90/0x90 include/linux/sched.h:1329 do_group_exit+0x125/0x340 kernel/exit.c:894 get_signal+0x47b/0x24e0 kernel/signal.c:2739 __get_unused_fd_flags+0x60/0x60 fs/file.c:545 do_signal+0x81/0x2240 arch/x86/kernel/signal.c:784 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 alloc_file+0x4e0/0x4e0 fs/file_table.c:205 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+0x171/0x260 kernel/locking/spinlock_debug.c:139 get_sigframe.isra.0+0x730/0x730 arch/x86/kernel/signal.c:268 rcu_read_unlock_sched include/linux/rcupdate.h:732 [inline] __fd_install+0x1e6/0x600 fs/file.c:613 __sys_socket+0x16d/0x200 net/socket.c:438 move_addr_to_kernel+0x70/0x70 net/socket.c:195 __ia32_sys_clock_settime+0x260/0x260 kernel/time/posix-timers.c:1410 exit_to_usermode_loop+0x26c/0x360 arch/x86/entry/common.c:161 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x6b1/0x7d0 arch/x86/entry/common.c:305 entry_SYSCALL_64_after_hwframe+0x49/0xb3 INFO: lockdep is turned off. NMI backtrace for cpu 0 CPU: 0 PID: 1144 Comm: khungtaskd Not tainted 5.7.0-rc6-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+0x188/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 lapic_can_unplug_cpu.cold+0x3b/0x3b nmi_trigger_cpumask_backtrace+0x231/0x27e lib/nmi_backtrace.c:62 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0xa8c/0x1010 kernel/hung_task.c:289 reset_hung_task_detector+0x30/0x30 kernel/hung_task.c:243 kthread+0x388/0x470 kernel/kthread.c:268 kthread_mod_delayed_work+0x1a0/0x1a0 kernel/kthread.c:1090 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:351 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60