INFO: task syz-executor.0:9763 blocked for more than 140 seconds. Not tainted 4.14.152 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor.0 D28024 9763 6901 0x00000004 Call Trace: context_switch kernel/sched/core.c:2807 [inline] __schedule+0x7b8/0x1cd0 kernel/sched/core.c:3383 schedule+0x92/0x1c0 kernel/sched/core.c:3427 __lock_sock+0x132/0x210 net/core/sock.c:2240 lock_sock_nested+0xee/0x110 net/core/sock.c:2764 lock_sock include/net/sock.h:1462 [inline] dccp_sendmsg+0xfb/0x950 net/dccp/proto.c:765 inet_sendmsg+0x122/0x500 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xce/0x110 net/socket.c:656 ___sys_sendmsg+0x349/0x840 net/socket.c:2062 __sys_sendmmsg+0x152/0x3a0 net/socket.c:2152 SYSC_sendmmsg net/socket.c:2183 [inline] SyS_sendmmsg+0x35/0x60 net/socket.c:2178 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a219 RSP: 002b:00007f1cd4758c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 000000000045a219 RDX: 00000000000003a6 RSI: 0000000020005700 RDI: 0000000000000006 RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1cd47596d4 R13: 00000000004c7f9d R14: 00000000004de3c8 R15: 00000000ffffffff Showing all locks held in the system: 1 lock held by khungtaskd/1016: #0: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0x7f/0x21f kernel/locking/lockdep.c:4544 2 locks held by getty/6851: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6852: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6853: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6854: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6855: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6856: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 2 locks held by getty/6857: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:376 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x1e6/0x17b0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1016 Comm: khungtaskd Not tainted 4.14.152 #0 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+0x138/0x197 lib/dump_stack.c:53 nmi_cpu_backtrace.cold+0x57/0x94 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x141/0x189 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:140 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:195 [inline] watchdog+0x5e7/0xb90 kernel/hung_task.c:274 kthread+0x319/0x430 kernel/kthread.c:232 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:404 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 9771 Comm: syz-executor.0 Not tainted 4.14.152 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff88806e7e6080 task.stack: ffff88805cae8000 RIP: 0010:mark_held_locks+0x9c/0x100 kernel/locking/lockdep.c:2841 RSP: 0018:ffff88805caef8c0 EFLAGS: 00000046 RAX: 0000000000000004 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000002 RSI: ffff88806e7e6900 RDI: ffff88806e7e6922 RBP: ffff88805caef8f8 R08: ffff88806e7e6080 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88806e7e6900 R13: 0000000000000002 R14: ffff88806e7e6080 R15: dffffc0000000000 FS: 00007f1cd4738700(0000) GS:ffff8880aef00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000001ca9108 CR3: 0000000073d2d000 CR4: 00000000001426e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:2871 [inline] trace_hardirqs_on_caller+0x19b/0x590 kernel/locking/lockdep.c:2926 trace_hardirqs_on+0xd/0x10 kernel/locking/lockdep.c:2933 seqcount_lockdep_reader_access include/linux/seqlock.h:83 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] ktime_get_with_offset+0x121/0x320 kernel/time/timekeeping.c:803 ktime_get_real include/linux/timekeeping.h:185 [inline] ccid3_hc_tx_send_packet+0x62/0x84b net/dccp/ccids/ccid3.c:284 ccid_hc_tx_send_packet net/dccp/ccid.h:170 [inline] dccp_write_xmit+0xad/0x1b0 net/dccp/output.c:353 dccp_sendmsg+0x7ad/0x950 net/dccp/proto.c:811 inet_sendmsg+0x122/0x500 net/ipv4/af_inet.c:762 sock_sendmsg_nosec net/socket.c:646 [inline] sock_sendmsg+0xce/0x110 net/socket.c:656 ___sys_sendmsg+0x70a/0x840 net/socket.c:2062 __sys_sendmsg+0xb9/0x140 net/socket.c:2096 SYSC_sendmsg net/socket.c:2107 [inline] SyS_sendmsg+0x2d/0x50 net/socket.c:2103 do_syscall_64+0x1e8/0x640 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x45a219 RSP: 002b:00007f1cd4737c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a219 RDX: 0000000000000000 RSI: 0000000020000440 RDI: 0000000000000006 RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f1cd47386d4 R13: 00000000004c87a3 R14: 00000000004dedb8 R15: 00000000ffffffff Code: c3 48 8d 04 80 49 8d 34 c4 48 8d 7e 22 48 89 f8 48 89 fa 48 c1 e8 03 83 e2 07 42 0f b6 04 38 38 d0 7f 04 84 c0 75 4d 0f b6 46 22 <8b> 55 d4 a8 03 41 0f 44 d5 a8 04 74 0c 4c 89 f7 e8 0f ed ff ff