INFO: task syz-executor.5:4448 blocked for more than 140 seconds. Not tainted 4.19.50 #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28472 4448 7935 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x80d/0x1c70 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618 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+0x288/0x4a0 net/can/af_can.c:183 __sock_create+0x3d8/0x730 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+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: Bad RIP value. RSP: 002b:00007f35a42dcc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459279 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f35a42dd6d4 R13: 00000000004c7c92 R14: 00000000004de178 R15: 00000000ffffffff INFO: task syz-executor.5:4553 blocked for more than 140 seconds. Not tainted 4.19.50 #22 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.5 D28472 4553 7935 0x00000004 Call Trace: context_switch kernel/sched/core.c:2826 [inline] __schedule+0x80d/0x1c70 kernel/sched/core.c:3474 schedule+0x92/0x1c0 kernel/sched/core.c:3518 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:589 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:618 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+0x288/0x4a0 net/can/af_can.c:183 __sock_create+0x3d8/0x730 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+0xfd/0x620 arch/x86/entry/common.c:293 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459279 Code: Bad RIP value. RSP: 002b:00007f35a42bbc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000029 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000459279 RDX: 0000000000000001 RSI: 0000000000000003 RDI: 000000000000001d RBP: 000000000075bfc0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f35a42bc6d4 R13: 00000000004c7c92 R14: 00000000004de178 R15: 00000000ffffffff Showing all locks held in the system: 3 locks held by kworker/u4:4/411: 1 lock held by khungtaskd/1033: #0: 0000000050d3fd14 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:4435 1 lock held by rsyslogd/7755: #0: 0000000018d35298 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:767 2 locks held by getty/7878: #0: 000000004ad9afa9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 0000000016474cd7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7879: #0: 000000000273260c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000001a852d86 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7880: #0: 0000000043d0ff37 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000d2c2b2e1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7881: #0: 00000000e8fccbd3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000e27d5d78 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7882: #0: 00000000ed28d5dc (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 000000007a669468 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7883: #0: 000000003e16217d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000321722d7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 2 locks held by getty/7884: #0: 00000000df63212f (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:363 #1: 00000000970902a0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b30 drivers/tty/n_tty.c:2154 1 lock held by syz-executor.5/4448: #0: 00000000d7a5631f (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 1 lock held by syz-executor.5/4553: #0: 00000000d7a5631f (pernet_ops_rwsem){++++}, at: register_netdevice_notifier+0x7e/0x630 net/core/dev.c:1642 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1033 Comm: khungtaskd Not tainted 4.19.50 #22 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+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 411 Comm: kworker/u4:4 Not tainted 4.19.50 #22 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: netns cleanup_net RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:23 [inline] RIP: 0010:preempt_latency_start kernel/sched/core.c:3172 [inline] RIP: 0010:preempt_count_add+0xa1/0x1b0 kernel/sched/core.c:3198 Code: fe 00 00 00 8b 15 df c3 ec 08 85 d2 75 15 65 8b 05 44 ab b8 7e 0f b6 c0 3d f4 00 00 00 0f 8f 80 00 00 00 65 8b 05 2f ab b8 7e <25> ff ff ff 7f 41 39 c4 74 05 5b 41 5c 5d c3 48 8b 5d 08 48 89 df RSP: 0018:ffff8880a8e1fad8 EFLAGS: 00000293 RAX: 0000000080000201 RBX: 0000000000000003 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8594ac1f RDI: 0000000000000001 RBP: ffff8880a8e1fae8 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffffffff88663f48 R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fdacc00d908 CR3: 000000009389d000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __raw_spin_lock include/linux/spinlock_api_smp.h:141 [inline] _raw_spin_lock+0x13/0x40 kernel/locking/spinlock.c:144 spin_lock include/linux/spinlock.h:329 [inline] nf_conntrack_lock+0x17/0x70 net/netfilter/nf_conntrack_core.c:96 get_next_corpse net/netfilter/nf_conntrack_core.c:1917 [inline] nf_ct_iterate_cleanup+0x1d7/0x4e0 net/netfilter/nf_conntrack_core.c:1951 nf_conntrack_cleanup_net_list+0x7a/0x250 net/netfilter/nf_conntrack_core.c:2138 nf_conntrack_pernet_exit+0x11d/0x170 net/netfilter/nf_conntrack_standalone.c:663 ops_exit_list.isra.0+0xfc/0x150 net/core/net_namespace.c:156 cleanup_net+0x3fb/0x960 net/core/net_namespace.c:552 process_one_work+0x989/0x1750 kernel/workqueue.c:2153 worker_thread+0x98/0xe40 kernel/workqueue.c:2296 kthread+0x354/0x420 kernel/kthread.c:246 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415