INFO: task syz-executor.1:3535 blocked for more than 140 seconds. Not tainted 4.19.42 #12 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29512 3535 7987 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x813/0x1d00 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:573 [inline] rwsem_down_write_failed+0x774/0xcc0 kernel/locking/rwsem-xadd.c:602 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 register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 raw_init+0x299/0x340 net/can/raw.c:343 can_create+0x28a/0x4b0 net/can/af_can.c:183 __sock_create+0x3e6/0x750 net/socket.c:1276 sock_create net/socket.c:1316 [inline] __sys_socket+0x103/0x220 net/socket.c:1346 __do_sys_socket net/socket.c:1355 [inline] __se_sys_socket net/socket.c:1353 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1353 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: Bad RIP value. RSP: 002b:00007fc9ea8a9c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc9ea8aa6d4 R13: 00000000004c74c9 R14: 00000000004dd448 R15: 00000000ffffffff INFO: task syz-executor.1:3539 blocked for more than 140 seconds. Not tainted 4.19.42 #12 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.1 D29512 3539 7987 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x813/0x1d00 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:573 [inline] rwsem_down_write_failed+0x774/0xcc0 kernel/locking/rwsem-xadd.c:602 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 register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 raw_init+0x299/0x340 net/can/raw.c:343 can_create+0x28a/0x4b0 net/can/af_can.c:183 __sock_create+0x3e6/0x750 net/socket.c:1276 sock_create net/socket.c:1316 [inline] __sys_socket+0x103/0x220 net/socket.c:1346 __do_sys_socket net/socket.c:1355 [inline] __se_sys_socket net/socket.c:1353 [inline] __x64_sys_socket+0x73/0xb0 net/socket.c:1353 do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: Bad RIP value. RSP: 002b:00007fc9ea888c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc9ea8896d4 R13: 00000000004c74c9 R14: 00000000004dd448 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1032: #0: 000000004b0b1407 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435 2 locks held by rs:main Q:Reg/7816: #0: 00000000cb7474f9 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 #1: 0000000051d5dacc (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2773 [inline] #1: 0000000051d5dacc (sb_writers#4){.+.+}, at: vfs_write+0x429/0x560 fs/read_write.c:548 1 lock held by rsyslogd/7818: #0: 000000001a1f662e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7940: #0: 000000001797732d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000dcec39aa (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7941: #0: 00000000e666b858 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000007253f138 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7942: #0: 00000000eae3b021 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000bc5130e3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7943: #0: 0000000082dd81c0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000048f0cc32 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7944: #0: 00000000432bf951 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000029c9d97b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7945: #0: 000000007c3e62ed (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000067c28a9c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7946: #0: 00000000e172911a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000008fb1fe62 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 3 locks held by kworker/u4:4/13111: 1 lock held by syz-executor.1/3535: #0: 00000000660fe9b5 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 1 lock held by syz-executor.1/3539: #0: 00000000660fe9b5 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1032 Comm: khungtaskd Not tainted 4.19.42 #12 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+0x1b0/0x1f8 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:203 [inline] watchdog+0x9df/0xee0 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 13111 Comm: kworker/u4:4 Not tainted 4.19.42 #12 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:lock_acquire+0xb/0x3f0 kernel/locking/lockdep.c:3889 Code: 85 70 ff ff ff e9 7a fc ff ff 48 c7 c7 c0 9b 44 8a e8 f9 20 4f 00 e9 c1 fb ff ff 0f 1f 40 00 48 b8 00 00 00 00 00 fc ff df 55 <45> 89 c3 48 89 e5 41 57 41 89 cf 41 56 41 89 d6 41 55 41 89 f5 41 RSP: 0018:ffff88809a327ae0 EFLAGS: 00000246 RAX: dffffc0000000000 RBX: 0000000000002260 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff88662fd8 RBP: ffff88809a327b00 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff88662fc0 R13: ffffffff88662fc0 R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c429653ac0 CR3: 00000000975ec000 CR4: 00000000001406f0 Call Trace: spin_lock include/linux/spinlock.h:329 [inline] nf_conntrack_lock+0x17/0x70 net/netfilter/nf_conntrack_core.c:95 get_next_corpse net/netfilter/nf_conntrack_core.c:1882 [inline] nf_ct_iterate_cleanup+0x1d7/0x4e0 net/netfilter/nf_conntrack_core.c:1916 nf_conntrack_cleanup_net_list+0x7a/0x250 net/netfilter/nf_conntrack_core.c:2103 nf_conntrack_pernet_exit+0x11d/0x170 net/netfilter/nf_conntrack_standalone.c:663 ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:156 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:552 process_one_work+0x98e/0x1760 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413