INFO: task syz-executor.0:30614 blocked for more than 143 seconds. Not tainted 5.2.0-rc2+ #14 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28688 30614 8843 0x80004002 Call Trace: context_switch kernel/sched/core.c:2818 [inline] __schedule+0x7cb/0x1560 kernel/sched/core.c:3445 schedule+0xa8/0x260 kernel/sched/core.c:3509 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:601 [inline] rwsem_down_write_failed+0x7a1/0xc60 kernel/locking/rwsem-xadd.c:633 __down_write kernel/locking/rwsem.h:227 [inline] down_write+0x93/0xa0 kernel/locking/rwsem.c:68 unregister_netdevice_notifier+0x7e/0x390 net/core/dev.c:1717 bcm_release+0x93/0x5d0 net/can/bcm.c:1525 __sock_release+0xce/0x2a0 net/socket.c:607 sock_close+0x1b/0x30 net/socket.c:1279 __fput+0x2ff/0x890 fs/file_table.c:280 ____fput+0x16/0x20 fs/file_table.c:313 task_work_run+0x145/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x90a/0x2fa0 kernel/exit.c:877 do_group_exit+0x135/0x370 kernel/exit.c:981 get_signal+0x41e/0x2240 kernel/signal.c:2638 do_signal+0x87/0x1900 arch/x86/kernel/signal.c:815 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:164 prepare_exit_to_usermode arch/x86/entry/common.c:199 [inline] syscall_return_slowpath arch/x86/entry/common.c:279 [inline] do_syscall_64+0x58e/0x680 arch/x86/entry/common.c:304 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: Bad RIP value. RSP: 002b:00007fa28533ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: 0000000000000004 RBX: 0000000000000003 RCX: 0000000000459279 RDX: 0000000000000002 RSI: 0000000000000002 RDI: 000000000000001d RBP: 000000000075c100 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fa28533f6d4 R13: 00000000004c7a41 R14: 00000000004ddc60 R15: 00000000ffffffff Showing all locks held in the system: 4 locks held by kworker/u4:0/7: #0: 0000000017f422e6 ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:221 [inline] #0: 0000000017f422e6 ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: 0000000017f422e6 ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: 0000000017f422e6 ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: 0000000017f422e6 ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: 0000000017f422e6 ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: 0000000017f422e6 ((wq_completion)netns){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240 #1: 0000000052ee30fa (net_cleanup_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244 #2: 000000009151924c (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x960 net/core/net_namespace.c:520 #3: 00000000dee88360 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76 1 lock held by khungtaskd/1043: #0: 00000000f3f7e736 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5149 1 lock held by rsyslogd/8715: #0: 0000000031766e8b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8804: #0: 000000004b5b997d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000023a3d51 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8805: #0: 0000000070e736ed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000237c2804 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8806: #0: 000000000d45c02e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000014017693 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8807: #0: 000000006f18026f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001e35499f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8808: #0: 000000009a976e8e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000059033a4d (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8809: #0: 00000000cd6e878c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c71beabf (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8810: #0: 00000000bcebb390 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000d46230b4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:14/1203: 2 locks held by syz-executor.0/30614: #0: 000000008ca6f25d (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:778 [inline] #0: 000000008ca6f25d (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2a0 net/socket.c:606 #1: 000000009151924c (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7e/0x390 net/core/dev.c:1717 1 lock held by syz-executor.0/30752: #0: 000000009151924c (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1c0/0x340 net/core/net_namespace.c:435 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.2.0-rc2+ #14 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+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:205 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:289 kthread+0x354/0x420 kernel/kthread.c:255 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 skipped: idling at native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:60