x86/PAT: syz-executor5:16482 map pfn RAM range req write-combining for [mem 0x19dd30000-0x19dd33fff], got write-back TCP: request_sock_TCPv6: Possible SYN flooding on port 20002. Sending cookies. Check SNMP counters. INFO: task syz-executor6:16476 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #3 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D22352 16476 15906 0x00000004 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:86 [inline] __wait_for_common kernel/sched/completion.c:107 [inline] wait_for_common kernel/sched/completion.c:118 [inline] wait_for_completion+0x415/0x770 kernel/sched/completion.c:139 ucma_destroy_id+0x2f0/0x500 drivers/infiniband/core/ucma.c:611 ucma_write+0x2d6/0x3d0 drivers/infiniband/core/ucma.c:1649 __vfs_write+0xef/0x970 fs/read_write.c:480 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454879 RSP: 002b:00007f386c351c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f386c3526d4 RCX: 0000000000454879 RDX: 0000000000000018 RSI: 0000000020000040 RDI: 0000000000000013 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000006a8 R14: 00000000006fc060 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/869: #0: (rcu_read_lock){....}, at: [<00000000b4794672>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000b4794672>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000d4dfbc2c>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 2 locks held by getty/4387: #0: (&tty->ldisc_sem){++++}, at: [<0000000055b14b2b>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e71f5920>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4388: #0: (&tty->ldisc_sem){++++}, at: [<0000000055b14b2b>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e71f5920>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4389: #0: (&tty->ldisc_sem){++++}, at: [<0000000055b14b2b>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e71f5920>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4390: #0: (&tty->ldisc_sem){++++}, at: [<0000000055b14b2b>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e71f5920>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4391: #0: (&tty->ldisc_sem){++++}, at: [<0000000055b14b2b>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e71f5920>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4392: #0: (&tty->ldisc_sem){++++}, at: [<0000000055b14b2b>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e71f5920>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4393: #0: (&tty->ldisc_sem){++++}, at: [<0000000055b14b2b>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e71f5920>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 4 locks held by kworker/0:7/6098: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000017704064>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000017704064>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000017704064>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<0000000017704064>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)#3){+.+.}, at: [<000000009d1a1e06>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cpu_hotplug_lock.rw_sem){++++}, at: [<0000000014dcbe3a>] get_online_cpus include/linux/cpu.h:124 [inline] #2: (cpu_hotplug_lock.rw_sem){++++}, at: [<0000000014dcbe3a>] memcg_destroy_kmem_caches+0xf/0x80 mm/slab_common.c:771 #3: (slab_mutex){+.+.}, at: [<00000000c145a7f7>] memcg_destroy_kmem_caches+0x24/0x80 mm/slab_common.c:774 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 869 Comm: khungtaskd Not tainted 4.16.0-rc7+ #3 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+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 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+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 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: 23 Comm: kworker/1:1 Not tainted 4.16.0-rc7+ #3 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: cgroup_destroy css_free_work_fn RIP: 0010:qlist_move_cache+0x73/0xf0 mm/kasan/quarantine.c:275 RSP: 0018:ffff8801d94670c8 EFLAGS: 00000086 RAX: ffff8801d3d06c00 RBX: 000077ff80000000 RCX: ffff8801d3d06c00 RDX: ffff8801d8a4fcc0 RSI: ffff8801d94670e8 RDI: ffffffff892d81a8 RBP: ffff8801d94670d8 R08: ffff8801d3d06ec0 R09: 0000000080000000 R10: ffff8801d3d06c40 R11: ffffea0000000000 R12: ffffea0007603d5f R13: ffffffff87bd6fa0 R14: ffffffff892d94e0 R15: ffff8801d8a4fcc0 FS: 0000000000000000(0000) GS:ffff8801db300000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000007a22002 CR4: 00000000001606e0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: quarantine_remove_cache+0x79/0xf0 mm/kasan/quarantine.c:317 kasan_cache_shutdown+0x9/0x10 mm/kasan/kasan.c:381 shutdown_cache+0x15/0x1b0 mm/slab_common.c:577 memcg_destroy_kmem_caches+0x62/0x80 mm/slab_common.c:781 memcg_free_kmem mm/memcontrol.c:2856 [inline] mem_cgroup_css_free+0x2a4/0x3f0 mm/memcontrol.c:4298 css_free_work_fn+0x1c8/0x1420 kernel/cgroup/cgroup.c:4541 process_one_work+0xc47/0x1bb0 kernel/workqueue.c:2113 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Code: 3f 00 8b 40 14 74 7f 4c 8b 47 08 49 89 08 48 89 4f 08 48 c7 01 00 00 00 00 4c 89 d1 48 01 47 10 4d 85 d2 74 5c 48 89 c8 4c 8b 11 <4c> 01 c8 72 62 49 89 d8 4c 01 c0 48 c1 e8 0c 48 c1 e0 06 4c 01