INFO: task syz-executor.4:20858 blocked for more than 143 seconds. Not tainted 5.1.0-rc4+ #141 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D27608 20858 16415 0x80000002 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x817/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:582 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:611 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 unregister_netdevice_notifier+0x7e/0x3a0 net/core/dev.c:1703 bcm_release+0x93/0x5d0 net/can/bcm.c:1525 __sock_release+0xd3/0x2b0 net/socket.c:599 sock_close+0x1b/0x30 net/socket.c:1247 __fput+0x2e5/0x8d0 fs/file_table.c:278 ____fput+0x16/0x20 fs/file_table.c:309 task_work_run+0x14a/0x1c0 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x90a/0x2fa0 kernel/exit.c:876 do_group_exit+0x135/0x370 kernel/exit.c:980 get_signal+0x399/0x1d50 kernel/signal.c:2577 do_signal+0x87/0x1940 arch/x86/kernel/signal.c:816 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline] syscall_return_slowpath arch/x86/entry/common.c:268 [inline] do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458c29 Code: Bad RIP value. RSP: 002b:00007f6772ab7cf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 000000000073bf08 RCX: 0000000000458c29 RDX: 00000000004c41bd RSI: 0000000000000081 RDI: 000000000073bf0c RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000073bf0c R13: 00007ffc275b1edf R14: 00007f6772ab89c0 R15: 000000000073bf0c Showing all locks held in the system: 1 lock held by khungtaskd/1042: #0: 0000000079f3ebcc (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061 3 locks held by kworker/u4:5/3071: 1 lock held by rsyslogd/7503: #0: 00000000a44031db (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7594: #0: 00000000491135f1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cb3fccc4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7595: #0: 000000006190cb90 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000003bc68feb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7596: #0: 00000000dd1f1918 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008d796c03 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7597: #0: 000000009895cb76 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000877094d9 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7598: #0: 000000001823b9a0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000040e2c880 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7599: #0: 000000008f3767f9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008df12d89 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7600: #0: 00000000b4f3748b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008a11f5d3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.1/29376: #0: 0000000002b8be30 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:772 [inline] #0: 0000000002b8be30 (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2b0 net/socket.c:598 2 locks held by syz-executor.4/20858: #0: 00000000036cc6aa (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:772 [inline] #0: 00000000036cc6aa (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2b0 net/socket.c:598 #1: 00000000a9954e35 (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7e/0x3a0 net/core/dev.c:1703 1 lock held by syz-executor.4/20950: #0: 00000000a9954e35 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1c0/0x340 net/core/net_namespace.c:434 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1042 Comm: khungtaskd Not tainted 5.1.0-rc4+ #141 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:204 [inline] watchdog+0x9b7/0xec0 kernel/hung_task.c:288 kthread+0x357/0x430 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: