TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. INFO: task syz-executor1:9502 blocked for more than 140 seconds. Not tainted 4.18.0+ #188 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D25528 9502 4465 0x00000004 Call Trace: context_switch kernel/sched/core.c:2823 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3471 schedule+0xfb/0x450 kernel/sched/core.c:3515 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 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+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:730 [inline] utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 do_utimes+0x1f7/0x380 fs/utimes.c:156 do_futimesat+0x249/0x350 fs/utimes.c:212 __do_sys_utimes fs/utimes.c:225 [inline] __se_sys_utimes fs/utimes.c:222 [inline] __x64_sys_utimes+0x59/0x80 fs/utimes.c:222 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007f2f01c2dc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000eb RAX: ffffffffffffffda RBX: 00007f2f01c2e6d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000020000180 RBP: 0000000000930140 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d68d0 R14: 00000000004c9f6a R15: 0000000000000001 INFO: task syz-executor1:9577 blocked for more than 140 seconds. Not tainted 4.18.0+ #188 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor1 D22616 9577 4465 0x00000004 Call Trace: context_switch kernel/sched/core.c:2823 [inline] __schedule+0x87c/0x1ec0 kernel/sched/core.c:3471 schedule+0xfb/0x450 kernel/sched/core.c:3515 __rwsem_down_write_failed_common+0x98b/0x1650 kernel/locking/rwsem-xadd.c:566 rwsem_down_write_failed+0xe/0x10 kernel/locking/rwsem-xadd.c:595 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+0xaa/0x130 kernel/locking/rwsem.c:72 inode_lock include/linux/fs.h:730 [inline] utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 do_utimes+0x1f7/0x380 fs/utimes.c:156 do_futimesat+0x249/0x350 fs/utimes.c:212 __do_sys_utimes fs/utimes.c:225 [inline] __se_sys_utimes fs/utimes.c:222 [inline] __x64_sys_utimes+0x59/0x80 fs/utimes.c:222 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457089 Code: 08 e8 3b a9 fb ff 48 8b 44 24 20 48 8b 4c 24 18 48 8b 54 24 38 48 8b 7c 24 48 eb 8d 48 8b 6c 24 50 48 83 c4 58 c3 48 89 04 24 <48> 89 5c 24 08 e8 0d a9 fb ff 48 8b 44 24 40 48 8b 4c 24 48 48 8b RSP: 002b:00007f2f01c0cc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000eb RAX: ffffffffffffffda RBX: 00007f2f01c0d6d4 RCX: 0000000000457089 RDX: 0000000000000000 RSI: 00000000200001c0 RDI: 0000000020000180 RBP: 00000000009301e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000004d68d0 R14: 00000000004c9f6a R15: 0000000000000002 Showing all locks held in the system: 1 lock held by khungtaskd/770: #0: 00000000361fa275 (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461 1 lock held by rsyslogd/4327: #0: 00000000b677a7a7 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766 2 locks held by getty/4418: #0: 0000000022aea5e9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000008a7a672e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4419: #0: 00000000d9318c7b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000e22b02c7 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4420: #0: 00000000e0c55eb1 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000055f1fa11 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4421: #0: 00000000ae4dd7e4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 00000000d0d066d1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4422: #0: 00000000fc47bb88 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001f36de79 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4423: #0: 0000000068b08437 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 000000001d8a40a4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by getty/4424: #0: 00000000a3b47722 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: 0000000030138994 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140 2 locks held by syz-executor1/9494: #0: 00000000f80b1fa8 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1569 [inline] #0: 00000000f80b1fa8 (sb_writers#20){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000221b188b (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:730 [inline] #1: 00000000221b188b (&sb->s_type->i_mutex_key#22){++++}, at: utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 2 locks held by syz-executor1/9502: #0: 00000000f80b1fa8 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1569 [inline] #0: 00000000f80b1fa8 (sb_writers#20){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000221b188b (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:730 [inline] #1: 00000000221b188b (&sb->s_type->i_mutex_key#22){++++}, at: utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 2 locks held by syz-executor1/9577: #0: 00000000a3da8fd3 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1569 [inline] #0: 00000000a3da8fd3 (sb_writers#20){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000629e4d3a (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:730 [inline] #1: 00000000629e4d3a (&sb->s_type->i_mutex_key#22){++++}, at: utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 2 locks held by syz-executor1/9578: #0: 00000000a3da8fd3 (sb_writers#20){.+.+}, at: sb_start_write include/linux/fs.h:1569 [inline] #0: 00000000a3da8fd3 (sb_writers#20){.+.+}, at: mnt_want_write+0x3f/0xc0 fs/namespace.c:386 #1: 00000000629e4d3a (&sb->s_type->i_mutex_key#22){++++}, at: inode_lock include/linux/fs.h:730 [inline] #1: 00000000629e4d3a (&sb->s_type->i_mutex_key#22){++++}, at: utimes_common.isra.1+0x45c/0x8e0 fs/utimes.c:90 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 770 Comm: khungtaskd Not tainted 4.18.0+ #188 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+0x1c9/0x2b4 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:144 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:196 [inline] watchdog+0x9c4/0xf80 kernel/hung_task.c:252 kthread+0x35a/0x420 kernel/kthread.c:246 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:413 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:56