INFO: task syz-executor6:16952 blocked for more than 120 seconds. Not tainted 4.15.0-rc7-mm1+ #56 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D24592 16952 4772 0x00000004 Call Trace: context_switch kernel/sched/core.c:2845 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3421 schedule+0xf5/0x430 kernel/sched/core.c:3480 io_schedule+0x1c/0x70 kernel/sched/core.c:5096 wait_on_page_bit_common mm/filemap.c:1099 [inline] __lock_page+0x574/0x720 mm/filemap.c:1272 lock_page include/linux/pagemap.h:483 [inline] pagecache_get_page+0x672/0xba0 mm/filemap.c:1553 find_lock_page include/linux/pagemap.h:297 [inline] truncate_inode_pages_range+0xc37/0x1fe0 mm/truncate.c:396 blkdev_fallocate+0x1ff/0x3b0 fs/block_dev.c:1990 vfs_fallocate+0x33c/0x6f0 fs/open.c:319 SYSC_fallocate fs/open.c:342 [inline] SyS_fallocate+0x53/0x90 fs/open.c:336 entry_SYSCALL_64_fastpath+0x29/0xa0 RIP: 0033:0x452e39 RSP: 002b:00007fd475cbec58 EFLAGS: 00000212 ORIG_RAX: 000000000000011d RAX: ffffffffffffffda RBX: 00007fd475cbf700 RCX: 0000000000452e39 RDX: 0000000000000000 RSI: 0000000000000003 RDI: 0000000000000013 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000100041 R11: 0000000000000212 R12: 0000000000000000 R13: 0000000000a2f7ef R14: 00007fd475cbf9c0 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/748: #0: (rcu_read_lock){....}, at: [<0000000079339ebe>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<0000000079339ebe>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000e1504c33>] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4464 2 locks held by getty/3634: #0: (&tty->ldisc_sem){++++}, at: [<00000000bf6b2b7a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003ceddea3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3635: #0: (&tty->ldisc_sem){++++}, at: [<00000000bf6b2b7a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003ceddea3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3636: #0: (&tty->ldisc_sem){++++}, at: [<00000000bf6b2b7a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003ceddea3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3637: #0: (&tty->ldisc_sem){++++}, at: [<00000000bf6b2b7a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003ceddea3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3638: #0: (&tty->ldisc_sem){++++}, at: [<00000000bf6b2b7a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003ceddea3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3639: #0: (&tty->ldisc_sem){++++}, at: [<00000000bf6b2b7a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003ceddea3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 2 locks held by getty/3640: #0: (&tty->ldisc_sem){++++}, at: [<00000000bf6b2b7a>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<000000003ceddea3>] n_tty_read+0x2ef/0x1a00 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 748 Comm: khungtaskd Not tainted 4.15.0-rc7-mm1+ #56 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+0x194/0x257 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+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x37/0x50 arch/x86/entry/entry_64.S:530 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