INFO: task syz-executor6:10100 blocked for more than 120 seconds. Not tainted 4.15.0-rc6-mm1+ #51 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D28304 10100 3704 0x00000004 Call Trace: context_switch kernel/sched/core.c:2800 [inline] __schedule+0x850/0x1e10 kernel/sched/core.c:3376 schedule+0x7c/0x1a0 kernel/sched/core.c:3435 io_schedule+0x1c/0x70 kernel/sched/core.c:5043 wait_on_page_bit_common mm/filemap.c:1099 [inline] wait_on_page_bit mm/filemap.c:1132 [inline] wait_on_page_locked include/linux/pagemap.h:530 [inline] __lock_page_or_retry+0x725/0x900 mm/filemap.c:1310 lock_page_or_retry include/linux/pagemap.h:510 [inline] filemap_fault+0xadf/0x1900 mm/filemap.c:2532 __do_fault+0x8a/0x1d0 mm/memory.c:3224 do_read_fault mm/memory.c:3634 [inline] do_fault mm/memory.c:3734 [inline] handle_pte_fault mm/memory.c:3965 [inline] __handle_mm_fault+0x1c96/0x3210 mm/memory.c:4089 handle_mm_fault+0x305/0x840 mm/memory.c:4126 faultin_page mm/gup.c:502 [inline] __get_user_pages+0x37e/0x1140 mm/gup.c:699 populate_vma_page_range+0x18e/0x230 mm/gup.c:1200 __mm_populate+0x204/0x350 mm/gup.c:1250 mm_populate include/linux/mm.h:2233 [inline] vm_mmap_pgoff+0x1e1/0x1f0 mm/util.c:338 SYSC_mmap_pgoff mm/mmap.c:1544 [inline] SyS_mmap_pgoff+0x423/0x580 mm/mmap.c:1502 SYSC_mmap arch/x86/kernel/sys_x86_64.c:100 [inline] SyS_mmap+0x16/0x20 arch/x86/kernel/sys_x86_64.c:91 entry_SYSCALL_64_fastpath+0x23/0x9a RIP: 0033:0x452ac9 RSP: 002b:00007ff15a347c58 EFLAGS: 00000212 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 000000000071bea0 RCX: 0000000000452ac9 RDX: 0000000000000004 RSI: 0000000000013000 RDI: 00000000201bc000 RBP: 000000000000034b R08: 0000000000000013 R09: 0000000000000000 R10: 0000000000008011 R11: 0000000000000212 R12: 00000000006f2fa8 R13: 00000000ffffffff R14: 00007ff15a3486d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/740: #0: (rcu_read_lock){....}, at: [<0000000051b8c711>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<0000000051b8c711>] watchdog+0x122/0xab0 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000e4efdca1>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4464 2 locks held by getty/3437: #0: (&tty->ldisc_sem){++++}, at: [<000000008470469a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c243d13c>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3438: #0: (&tty->ldisc_sem){++++}, at: [<000000008470469a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c243d13c>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3439: #0: (&tty->ldisc_sem){++++}, at: [<000000008470469a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c243d13c>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3440: #0: (&tty->ldisc_sem){++++}, at: [<000000008470469a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c243d13c>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3441: #0: (&tty->ldisc_sem){++++}, at: [<000000008470469a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c243d13c>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3442: #0: (&tty->ldisc_sem){++++}, at: [<000000008470469a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c243d13c>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 2 locks held by getty/3443: #0: (&tty->ldisc_sem){++++}, at: [<000000008470469a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000c243d13c>] n_tty_read+0x1ec/0x1660 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 740 Comm: khungtaskd Not tainted 4.15.0-rc6-mm1+ #51 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+0x137/0x198 lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x122/0x180 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+0x73d/0xab0 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:524 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:54