INFO: task syz-executor.4:18262 blocked for more than 140 seconds. Not tainted 4.16.0-rc4+ #1 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.4 D28472 18262 6523 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x7b7/0x1d80 kernel/sched/core.c:3440 schedule+0x7f/0x1b0 kernel/sched/core.c:3499 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3557 __mutex_lock_common kernel/locking/mutex.c:833 [inline] __mutex_lock+0xa61/0x14e0 kernel/locking/mutex.c:893 mutex_lock_nested+0x16/0x20 kernel/locking/mutex.c:908 genl_lock net/netlink/genetlink.c:33 [inline] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 netlink_rcv_skb+0x145/0x390 net/netlink/af_netlink.c:2444 genl_rcv+0x23/0x40 net/netlink/genetlink.c:635 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline] netlink_unicast+0x44a/0x650 net/netlink/af_netlink.c:1334 netlink_sendmsg+0x73e/0xc50 net/netlink/af_netlink.c:1897 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xb7/0xf0 net/socket.c:639 ___sys_sendmsg+0x649/0x950 net/socket.c:2047 __sys_sendmsg+0xc9/0x160 net/socket.c:2081 SYSC_sendmsg net/socket.c:2092 [inline] SyS_sendmsg+0xd/0x20 net/socket.c:2088 do_syscall_64+0x1c9/0x6a0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x4120e1 RSP: 002b:00007f938c48a9c0 EFLAGS: 00000293 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f938c48aa58 RCX: 00000000004120e1 RDX: 0000000000000000 RSI: 00007f938c48aa00 RDI: 0000000000000005 RBP: 0000000000000005 R08: 000000000000000b R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 00007f938c48aa40 R13: 00000000004cdae0 R14: 00000000004dbe60 R15: 00000000ffffffff Showing all locks held in the system: 2 locks held by khungtaskd/1003: #0: (rcu_read_lock){....}, at: [<0000000081abe8a7>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<0000000081abe8a7>] watchdog+0xfc/0x8e0 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<0000000086d01b89>] debug_show_all_locks+0x79/0x222 kernel/locking/lockdep.c:4470 2 locks held by getty/6410: #0: (&tty->ldisc_sem){++++}, at: [<000000008c8bfda5>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff9e6188>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6411: #0: (&tty->ldisc_sem){++++}, at: [<000000008c8bfda5>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff9e6188>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6412: #0: (&tty->ldisc_sem){++++}, at: [<000000008c8bfda5>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff9e6188>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6413: #0: (&tty->ldisc_sem){++++}, at: [<000000008c8bfda5>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff9e6188>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6414: #0: (&tty->ldisc_sem){++++}, at: [<000000008c8bfda5>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff9e6188>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6415: #0: (&tty->ldisc_sem){++++}, at: [<000000008c8bfda5>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff9e6188>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by getty/6416: #0: (&tty->ldisc_sem){++++}, at: [<000000008c8bfda5>] ldsem_down_read+0x2d/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000ff9e6188>] n_tty_read+0x1ee/0x16c0 drivers/tty/n_tty.c:2131 2 locks held by syz-executor.4/18262: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.4/18279: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.3/18273: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.3/18283: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.2/18274: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.2/18280: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.0/18276: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.1/18278: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 2 locks held by syz-executor.1/18282: #0: (cb_lock){++++}, at: [<000000001cfe121a>] genl_rcv+0x14/0x40 net/netlink/genetlink.c:634 #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_lock net/netlink/genetlink.c:33 [inline] #1: (genl_mutex){+.+.}, at: [<00000000cfcc16b6>] genl_rcv_msg+0x10e/0x140 net/netlink/genetlink.c:622 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1003 Comm: khungtaskd Not tainted 4.16.0-rc4+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0xed/0x131 lib/dump_stack.c:53 nmi_cpu_backtrace.cold.5+0x13/0xb2 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0xf5/0x119 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+0x5a8/0x8e0 kernel/hung_task.c:249 kthread+0x319/0x3e0 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 18265 Comm: syz-executor.5 Not tainted 4.16.0-rc4+ #1 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_is_held+0x9e/0x140 kernel/locking/lockdep.c:3738 RSP: 0018:ffff880093ab6d50 EFLAGS: 00000002 RAX: 0000000000000000 RBX: ffff88008e45e938 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff88276d40 RDI: ffff88008e45e95a RBP: ffff880093ab6d90 R08: 0000000000000000 R09: ffff88009bf9ddfe R10: 0000000000000078 R11: ffff88008e45e080 R12: ffff88008e45e080 R13: ffffed0011c8bd26 R14: ffff88008e45e938 R15: 0000000000000001 FS: 00007f288b704700(0000) GS:ffff8800aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c42045be80 CR3: 000000009a716000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held_type+0x118/0x210 kernel/locking/lockdep.c:3958 lock_is_held include/linux/lockdep.h:344 [inline] genl_family_attrbuf+0x9f/0xd0 net/netlink/genetlink.c:1074 tipc_nlmsg_parse+0x26/0xd0 net/tipc/netlink.c:267 tipc_nl_publ_dump+0x760/0xccc net/tipc/socket.c:3340 __tipc_nl_compat_dumpit.isra.11+0x1a2/0x8e0 net/tipc/netlink_compat.c:192 tipc_nl_compat_publ_dump net/tipc/netlink_compat.c:919 [inline] tipc_nl_compat_sk_dump+0x656/0x970 net/tipc/netlink_compat.c:967 __tipc_nl_compat_dumpit.isra.11+0x27a/0x8e0 net/tipc/netlink_compat.c:201 tipc_nl_compat_dumpit+0x1a5/0x400 net/tipc/netlink_compat.c:265 tipc_nl_compat_handle net/tipc/netlink_compat.c:1141 [inline] tipc_nl_compat_recv+0x45d/0xa70 net/tipc/netlink_compat.c:1204 genl_family_rcv_msg+0x5a2/0x1010 net/netlink/genetlink.c:599 genl_rcv_msg+0xa7/0x140 net/netlink/genetlink.c:624 netlink_rcv_skb+0x145/0x390 net/netlink/af_netlink.c:2444 genl_rcv+0x23/0x40 net/netlink/genetlink.c:635 netlink_unicast_kernel net/netlink/af_netlink.c:1308 [inline] netlink_unicast+0x44a/0x650 net/netlink/af_netlink.c:1334 netlink_sendmsg+0x73e/0xc50 net/netlink/af_netlink.c:1897 sock_sendmsg_nosec net/socket.c:629 [inline] sock_sendmsg+0xb7/0xf0 net/socket.c:639 ___sys_sendmsg+0x649/0x950 net/socket.c:2047 __sys_sendmsg+0xc9/0x160 net/socket.c:2081 SYSC_sendmsg net/socket.c:2092 [inline] SyS_sendmsg+0xd/0x20 net/socket.c:2088 do_syscall_64+0x1c9/0x6a0 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x458209 RSP: 002b:00007f288b703c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458209 RDX: 0000000000000000 RSI: 0000000020000500 RDI: 0000000000000006 RBP: 000000000073bfa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f288b7046d4 R13: 00000000004cbcb8 R14: 00000000004d9400 R15: 00000000ffffffff Code: 08 00 00 85 c0 7f 24 e9 85 00 00 00 41 0f b6 45 00 41 83 c7 01 84 c0 74 08 3c 03 0f 8e 8f 00 00 00 45 39 bc 24 b0 08 00 00 7e 66 <49> 63 c7 48 8b 75 d0 48 8d 04 80 49 8d 1c c6 48 89 df e8 0b f8