INFO: task syz-executor.4:5089 blocked for more than 140 seconds. Not tainted 4.19.43 #13 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29480 5089 31702 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+0x103/0x630 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: Bad RIP value. RSP: 002b:00007f1c79d06c78 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: 00007f1c79d076d4 R13: 00000000004c74c9 R14: 00000000004dd4b8 R15: 00000000ffffffff INFO: task syz-executor.4:5102 blocked for more than 140 seconds. Not tainted 4.19.43 #13 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D29512 5102 31702 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+0x103/0x630 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x458da9 Code: Bad RIP value. RSP: 002b:00007f1c79cc4c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458da9 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1c79cc56d4 R13: 00000000004c74c9 R14: 00000000004dd4b8 R15: 00000000ffffffff Showing all locks held in the system: 4 locks held by kworker/u4:3/218: 1 lock held by khungtaskd/1033: #0: 000000000cc9c077 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435 2 locks held by rs:main Q:Reg/7610: #0: 000000005b67ba0e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 #1: 0000000012c87e6a (sb_writers#4){.+.+}, at: file_start_write include/linux/fs.h:2773 [inline] #1: 0000000012c87e6a (sb_writers#4){.+.+}, at: vfs_write+0x429/0x560 fs/read_write.c:548 1 lock held by rsyslogd/7613: #0: 000000003de0c5cc (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7734: #0: 0000000008e13718 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000008b29bde7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7735: #0: 000000008e07ed8c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000007d26c1da (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7736: #0: 000000006180a865 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000f63f9b44 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7737: #0: 000000007e8784d0 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000d778284f (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7738: #0: 00000000c90244fd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000be33f50c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7739: #0: 00000000a56057aa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000002b5d1bb (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7740: #0: 00000000c81fc5ff (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000f585465b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 1 lock held by syz-executor.4/5089: #0: 0000000050245265 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 1 lock held by syz-executor.4/5102: #0: 0000000050245265 (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1033 Comm: khungtaskd Not tainted 4.19.43 #13 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 218 Comm: kworker/u4:3 Not tainted 4.19.43 #13 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:match_held_lock+0x230/0x500 kernel/locking/lockdep.c:3503 Code: ea 03 80 3c 02 00 0f 85 d6 02 00 00 4e 8b 24 e5 a0 34 e7 89 49 be 00 00 00 00 00 fc ff df 4d 85 e4 75 40 31 c0 48 83 c4 08 5b <41> 5c 41 5d 41 5e 41 5f 5d c3 48 83 c4 08 b8 01 00 00 00 5b 41 5c RSP: 0018:ffff8880a975fa48 EFLAGS: 00000092 RAX: 0000000000000000 RBX: ffff8880a9756440 RCX: ffff8880a9756cc0 RDX: 0000000000000000 RSI: ffffffff8879d9a0 RDI: ffff8880a9756ce2 RBP: ffff8880a975fa68 R08: ffff8880a9756440 R09: ffff8880a9756d30 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff8879d9a0 R13: ffffed10152ead97 R14: 0000000000000000 R15: ffff8880a9756cc0 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000458d7f CR3: 00000000a14a9000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_is_held+0xb6/0x140 kernel/locking/lockdep.c:3720 lock_is_held_type+0x110/0x210 kernel/locking/lockdep.c:3938 lock_is_held include/linux/lockdep.h:344 [inline] ___might_sleep+0x1c4/0x280 kernel/sched/core.c:6115 get_next_corpse net/netfilter/nf_conntrack_core.c:1894 [inline] nf_ct_iterate_cleanup+0x22a/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