RAX: ffffffffffffffda RBX: 00007fb8e93a56d4 RCX: 0000000000455979 RDX: 0000000000000040 RSI: 0000000020001f00 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000014 R13: 0000000000000536 R14: 00000000006fbdb0 R15: 0000000000000001 INFO: task syz-executor4:597 blocked for more than 120 seconds. Not tainted 4.17.0-rc3+ #40 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor4 D21736 597 4546 0x80000002 Call Trace: context_switch kernel/sched/core.c:2848 [inline] __schedule+0x801/0x1e30 kernel/sched/core.c:3490 schedule+0xef/0x430 kernel/sched/core.c:3549 schedule_timeout+0x1b5/0x240 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:83 [inline] __wait_for_common kernel/sched/completion.c:104 [inline] wait_for_common kernel/sched/completion.c:115 [inline] wait_for_completion+0x3e7/0x870 kernel/sched/completion.c:136 __wait_rcu_gp+0x257/0x350 kernel/rcu/update.c:414 synchronize_sched.part.64+0xe3/0xf0 kernel/rcu/tree.c:3209 synchronize_sched+0x76/0xf0 kernel/rcu/tree.c:3210 synchronize_rcu include/linux/rcupdate.h:94 [inline] pfkey_release+0x399/0x560 net/key/af_key.c:193 sock_release+0x96/0x1b0 net/socket.c:594 sock_close+0x16/0x20 net/socket.c:1149 __fput+0x34d/0x890 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x1e4/0x290 kernel/task_work.c:113 exit_task_work include/linux/task_work.h:22 [inline] do_exit+0x1aee/0x2730 kernel/exit.c:865 do_group_exit+0x16f/0x430 kernel/exit.c:968 get_signal+0x886/0x1960 kernel/signal.c:2469 do_signal+0x98/0x2040 arch/x86/kernel/signal.c:810 exit_to_usermode_loop+0x28a/0x310 arch/x86/entry/common.c:162 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ac/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455979 RSP: 002b:00007f620f631c88 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f620f6326d4 RCX: 0000000000455979 RDX: 0000000000000010 RSI: 0000000000000001 RDI: 000000000072becc RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 0000000000000538 R14: 00000000006fbde0 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/892: #0: 000000009c6d2400 (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: 000000009c6d2400 (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249 #1: 00000000dd725bda (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470 2 locks held by getty/4465: #0: 000000000607ceaf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000002de2c11b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4466: #0: 00000000607b6efb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000070bc9911 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4467: #0: 000000008edc371e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000004bd20d1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4468: #0: 00000000fb4f9545 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000667877da (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4469: #0: 00000000f1196c48 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000119e35c1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4470: #0: 00000000c80bd599 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000329a8f11 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 2 locks held by getty/4471: #0: 00000000b016d2e5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000a86444ab (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 892 Comm: khungtaskd Not tainted 4.17.0-rc3+ #40 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+0x1b9/0x294 lib/dump_stack.c:113 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x151/0x192 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:138 [inline] check_hung_task kernel/hung_task.c:132 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:190 [inline] watchdog+0xc10/0xf60 kernel/hung_task.c:249 kthread+0x345/0x410 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 640 Comm: syz-executor3 Not tainted 4.17.0-rc3+ #40 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__read_once_size include/linux/compiler.h:188 [inline] RIP: 0010:check_kcov_mode kernel/kcov.c:69 [inline] RIP: 0010:write_comp_data+0x22/0x70 kernel/kcov.c:122 RSP: 0018:ffff880199b2e428 EFLAGS: 00000246 RAX: 0000000000000002 RBX: 0000000000000009 RCX: ffffffff868d9d58 RDX: 0000000000000000 RSI: 0000000000000084 RDI: 0000000000000001 RBP: ffff880199b2e428 R08: ffff8801aeca0640 R09: ffff880199b2e7c8 R10: ffffed0033365d03 R11: ffff880199b2e81f R12: ffffffff88565ec0 R13: 0000000000000000 R14: 0000000000000001 R15: 000000000000000b FS: 00007f3696abe700(0000) GS:ffff8801daf00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000004cd7a0 CR3: 00000001bb6f3000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __sanitizer_cov_trace_switch+0x53/0x90 kernel/kcov.c:224 _decode_session6+0x4c8/0x14f0 net/ipv6/xfrm6_policy.c:154 __xfrm_decode_session+0x71/0x140 net/xfrm/xfrm_policy.c:2368 __xfrm_policy_check+0x1a0/0x2650 net/xfrm/xfrm_policy.c:2403 __xfrm_policy_check2 include/net/xfrm.h:1170 [inline] xfrm_policy_check include/net/xfrm.h:1175 [inline] xfrm6_policy_check include/net/xfrm.h:1185 [inline] ip6_input_finish+0x15f3/0x1a30 net/ipv6/ip6_input.c:302 NF_HOOK include/linux/netfilter.h:288 [inline] ip6_input+0xe1/0x5e0 net/ipv6/ip6_input.c:327 dst_input include/net/dst.h:450 [inline] ip6_rcv_finish+0x29c/0xa10 net/ipv6/ip6_input.c:71 NF_HOOK include/linux/netfilter.h:288 [inline] ipv6_rcv+0xeb8/0x2040 net/ipv6/ip6_input.c:208 __netif_receive_skb_core+0x2468/0x3650 net/core/dev.c:4646 __netif_receive_skb+0x2c/0x1e0 net/core/dev.c:4711 netif_receive_skb_internal+0x126/0x7b0 net/core/dev.c:4785 netif_receive_skb+0xba/0x400 net/core/dev.c:4809 tun_rx_batched.isra.53+0x4ba/0x8c0 drivers/net/tun.c:1560 tun_get_user+0x2ac3/0x4290 drivers/net/tun.c:1968 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1996 call_write_iter include/linux/fs.h:1784 [inline] do_iter_readv_writev+0x859/0xa50 fs/read_write.c:680 do_iter_write+0x185/0x5f0 fs/read_write.c:959 vfs_writev+0x1c7/0x330 fs/read_write.c:1004 do_writev+0x112/0x2f0 fs/read_write.c:1039 __do_sys_writev fs/read_write.c:1112 [inline] __se_sys_writev fs/read_write.c:1109 [inline] __x64_sys_writev+0x75/0xb0 fs/read_write.c:1109 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x455831 RSP: 002b:00007f3696abdba0 EFLAGS: 00000293 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 000000000000fdef RCX: 0000000000455831 RDX: 0000000000000001 RSI: 00007f3696abdbf0 RDI: 00000000000000fc RBP: 00000000200001c0 R08: 00000000000000fc R09: 0000000000000000 R10: 000000000000fdef R11: 0000000000000293 R12: 00000000ffffffff R13: 00000000000006ad R14: 00000000006fe0d8 R15: 0000000000000000 Code: 65 3c 00 e9 86 fc ff ff 90 55 65 4c 8b 04 25 c0 ed 01 00 65 8b 05 0f be 88 7e 48 89 e5 a9 00 01 1f 00 75 51 41 8b 80 78 12 00 00 <83> f8 03 75 45 49 8b 80 80 12 00 00 45 8b 80 7c 12 00 00 4c 8b INFO: NMI handler (nmi_cpu_backtrace_handler) took too long to run: 1.372 msecs