INFO: task syz-executor.5:343 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.5 D27552 343 7604 0x00000004 Call Trace: context_switch kernel/sched/core.c:3367 [inline] __schedule+0x937/0x1ff0 kernel/sched/core.c:4083 rwsem_down_write_slowpath+0x90a/0xf90 kernel/locking/rwsem.c:1216 __sched_text_start+0x8/0x8 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 rwsem_down_write_slowpath+0x706/0xf90 kernel/locking/rwsem.c:1235 pcpu_alloc+0xfed/0x13b0 mm/percpu.c:1703 rwsem_mark_wake+0x8d0/0x8d0 include/linux/compiler.h:199 lock_acquire+0x1f2/0x8f0 kernel/locking/lockdep.c:4934 register_netdevice_notifier+0x1e/0x270 net/core/dev.c:1729 lock_release+0x800/0x800 kernel/locking/lockdep.c:4689 __down_write kernel/locking/rwsem.c:1389 [inline] down_write+0x137/0x150 kernel/locking/rwsem.c:1532 atomic64_try_cmpxchg include/asm-generic/atomic-instrumented.h:1504 [inline] atomic_long_try_cmpxchg_acquire include/asm-generic/atomic-long.h:442 [inline] __down_write kernel/locking/rwsem.c:1387 [inline] down_write+0xb2/0x150 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 pcpu_alloc+0x128/0x13b0 mm/percpu.c:1740 register_netdevice_notifier+0x1e/0x270 net/core/dev.c:1729 raw_init+0x296/0x340 net/can/raw.c:339 raw_sock_no_ioctlcmd+0x10/0x10 net/can/raw.c:843 can_create+0x27c/0x500 net/can/af_can.c:168 __sock_create+0x3cb/0x730 net/socket.c:1433 sock_create net/socket.c:1484 [inline] __sys_socket+0xef/0x200 net/socket.c:1526 move_addr_to_kernel+0x70/0x70 net/socket.c:195 __do_sys_clock_gettime kernel/time/posix-timers.c:1094 [inline] __se_sys_clock_gettime kernel/time/posix-timers.c:1082 [inline] __x64_sys_clock_gettime+0x165/0x240 kernel/time/posix-timers.c:1082 __ia32_sys_clock_settime+0x260/0x260 kernel/time/posix-timers.c:1410 trace_hardirqs_off_caller+0x55/0x230 kernel/trace/trace_preemptirq.c:73 __do_sys_socket net/socket.c:1535 [inline] __se_sys_socket net/socket.c:1533 [inline] __x64_sys_socket+0x6f/0xb0 net/socket.c:1533 __trace_hardirqs_on_caller kernel/locking/lockdep.c:3657 [inline] lockdep_hardirqs_on+0x463/0x620 kernel/locking/lockdep.c:3702 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 Showing all locks held in the system: 1 lock held by khungtaskd/1140: #0: ffffffff899bea80 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x53/0x260 kernel/locking/lockdep.c:5754 5 locks held by kworker/u4:8/8878: #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_data kernel/workqueue.c:615 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: set_work_pool_and_clear_pending kernel/workqueue.c:642 [inline] #0: ffff8880a9771938 ((wq_completion)netns){+.+.}-{0:0}, at: process_one_work+0x844/0x16a0 kernel/workqueue.c:2239 #1: ffffc90018187dc0 (net_cleanup_work){+.+.}-{0:0}, at: process_one_work+0x878/0x16a0 kernel/workqueue.c:2243 #2: ffffffff8a57aa70 (pernet_ops_rwsem){++++}-{3:3}, at: cleanup_net+0x9b/0xa50 net/core/net_namespace.c:565 #3: ffffffff8a586968 (rtnl_mutex){+.+.}-{3:3}, at: caif_exit_net+0x2c8/0x790 net/caif/caif_dev.c:522 #4: ffff8880472a3880 (&caifn->caifdevs.lock){+.+.}-{3:3}, at: caif_exit_net+0x2e3/0x790 net/caif/caif_dev.c:523 1 lock held by syz-executor.5/343: #0: ffffffff8a57aa70 (pernet_ops_rwsem){++++}-{3:3}, at: register_netdevice_notifier+0x1e/0x270 net/core/dev.c:1729 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1140 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 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4231 Comm: systemd-journal Not tainted 5.7.0-rc6-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:199 [inline] RIP: 0010:trace_rcu_utilization include/trace/events/rcu.h:27 [inline] RIP: 0010:trace_rcu_utilization include/trace/events/rcu.h:27 [inline] RIP: 0010:rcu_note_context_switch+0x840/0x18f0 kernel/rcu/tree_plugin.h:293 Code: e8 85 6a ff ff e9 3c fa ff ff 65 ff 05 f1 54 a1 7e 48 c7 c0 28 17 85 8a 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 <0f> 85 30 0b 00 00 48 8b 05 2b 4d 24 09 e8 4e eb fe ff 85 c0 74 0d RSP: 0018:ffffc90001077ab8 EFLAGS: 00000046 RAX: 1ffffffff150a2e5 RBX: ffff8880ae638740 RCX: ffffffff8160c233 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: ffffffff8a899240 RBP: 0000000000000000 R08: ffff888094016180 R09: fffffbfff1513249 R10: ffffffff8a899247 R11: fffffbfff1513248 R12: 0000000000000000 R13: ffff888094016180 R14: 0000000000037980 R15: ffff8880ae637998 FS: 00007fd0cd5fd8c0(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fd0ca522010 CR3: 00000000969ad000 CR4: 00000000001426f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __schedule+0x22b/0x1ff0 kernel/sched/core.c:4019 find_held_lock+0x2d/0x110 kernel/locking/lockdep.c:4458 __sched_text_start+0x8/0x8 atomic64_cmpxchg include/asm-generic/atomic-instrumented.h:1463 [inline] atomic_long_cmpxchg_release include/asm-generic/atomic-long.h:424 [inline] __mutex_unlock_slowpath+0xe2/0x660 kernel/locking/mutex.c:1249 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 schedule+0xd0/0x2a0 kernel/sched/core.c:4158 schedule_hrtimeout_range_clock+0x2ef/0x340 kernel/time/hrtimer.c:2128 hrtimer_nanosleep_restart+0x140/0x140 kernel/time/hrtimer.c:1916 ep_scan_ready_list+0x602/0x960 fs/eventpoll.c:756 lock_downgrade+0x840/0x840 kernel/locking/lockdep.c:4579 atomic_try_cmpxchg include/asm-generic/atomic-instrumented.h:694 [inline] queued_write_lock include/asm-generic/qrwlock.h:92 [inline] do_raw_write_lock+0x11a/0x280 kernel/locking/spinlock_debug.c:207 do_raw_read_unlock+0x70/0x70 kernel/locking/spinlock_debug.c:176 __raw_write_unlock_irq include/linux/rwlock_api_smp.h:267 [inline] _raw_write_unlock_irq+0x1f/0x80 kernel/locking/spinlock.c:343 ep_poll+0xcef/0xf00 fs/eventpoll.c:1910 ep_send_events_proc+0xc30/0xc30 include/linux/list.h:72 debug_object_deactivate+0x320/0x320 lib/debugobjects.c:714 __secure_computing+0x104/0x360 kernel/seccomp.c:950 finish_wait+0x260/0x260 include/linux/list.h:301 syscall_slow_exit_work+0x630/0x630 include/linux/tracehook.h:75 do_epoll_wait+0x209/0x260 fs/eventpoll.c:2333 trace_hardirqs_off_caller+0x55/0x230 kernel/trace/trace_preemptirq.c:73 __do_sys_epoll_wait fs/eventpoll.c:2343 [inline] __se_sys_epoll_wait fs/eventpoll.c:2340 [inline] __x64_sys_epoll_wait+0x93/0xf0 fs/eventpoll.c:2340 do_syscall_64+0xf6/0x7d0 arch/x86/entry/common.c:295 entry_SYSCALL_64_after_hwframe+0x49/0xb3 RIP: 0033:0x7fd0cc8c72e3 Code: 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 83 3d 29 54 2b 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 0b c2 00 00 48 89 04 24 RSP: 002b:00007fffc1ccf0d8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8 RAX: ffffffffffffffda RBX: 000055eb175e31e0 RCX: 00007fd0cc8c72e3 RDX: 0000000000000013 RSI: 00007fffc1ccf0e0 RDI: 0000000000000008 RBP: 00007fffc1ccf2d0 R08: 00007fffc1d0c080 R09: 000000005ec86c34 R10: 00000000ffffffff R11: 0000000000000246 R12: 00007fffc1ccf0e0 R13: 0000000000000001 R14: ffffffffffffffff R15: 0005a645b518059c