INFO: task syz-executor.1:31664 blocked for more than 143 seconds. Not tainted 5.1.0-rc6+ #192 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D28384 31664 18468 0x00000004 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 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:1717 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 tracehook_notify_resume include/linux/tracehook.h:188 [inline] exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166 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: 0033:0x412b61 Code: 24 00 8b 93 04 01 00 00 85 d2 89 54 24 0c 0f 8e 2f 02 00 00 4c 8b 7c 24 28 c7 44 24 20 00 00 00 00 41 bd ff ff ff ff 45 31 f6 40 0f 1f 44 00 00 48 8b 75 00 48 85 f6 74 3a 48 8b 7c 24 10 e8 RSP: 002b:00007ffc5e2e90c0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000412b61 RDX: 0000001b2df20000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00000000b334236b R09: 00000000b334236f R10: 00007ffc5e2e91a0 R11: 0000000000000293 R12: 000000000073c900 R13: 000000000073c900 R14: 000000000015840f R15: 000000000073bfac Showing all locks held in the system: 1 lock held by khungtaskd/1043: #0: 000000004fd4f3b0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5057 1 lock held by rsyslogd/8022: #0: 000000002673ed2e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8134: #0: 00000000ff79df5b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000af2f3944 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8135: #0: 00000000229494a4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000f21b0e22 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8136: #0: 000000009b8da173 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000c8fd8b05 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8137: #0: 00000000057dafcb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000161978c1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8138: #0: 0000000001d87cd4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000000c1519e5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8139: #0: 00000000413ae2b4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000040c4ba0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8140: #0: 000000009bf3fc00 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000bf8ff510 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 3 locks held by kworker/u4:7/12026: 2 locks held by syz-executor.1/31664: #0: 000000009d9ad3b7 (&sb->s_type->i_mutex_key#11){+.+.}, at: inode_lock include/linux/fs.h:772 [inline] #0: 000000009d9ad3b7 (&sb->s_type->i_mutex_key#11){+.+.}, at: __sock_release+0x89/0x2b0 net/socket.c:598 #1: 000000008e348210 (pernet_ops_rwsem){++++}, at: unregister_netdevice_notifier+0x7e/0x3a0 net/core/dev.c:1717 1 lock held by syz-executor.0/31695: #0: 000000008e348210 (pernet_ops_rwsem){++++}, at: copy_net_ns+0x1c0/0x340 net/core/net_namespace.c:434 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc6+ #192 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 0 to CPUs 1: