INFO: task syz-executor0:7749 blocked for more than 120 seconds. Not tainted 4.14.0+ #190 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D19920 7749 3278 0x00000004 Call Trace: context_switch kernel/sched/core.c:2799 [inline] __schedule+0x8eb/0x2060 kernel/sched/core.c:3375 schedule+0xf5/0x430 kernel/sched/core.c:3434 io_schedule+0x1c/0x70 kernel/sched/core.c:5042 __blkdev_direct_IO_simple+0x760/0xef0 fs/block_dev.c:241 blkdev_direct_IO+0xc8a/0x1000 fs/block_dev.c:428 generic_file_read_iter+0x4d2/0x28f0 mm/filemap.c:2344 blkdev_read_iter+0x105/0x170 fs/block_dev.c:1913 call_read_iter include/linux/fs.h:1766 [inline] generic_file_splice_read+0x3ff/0x7c0 fs/splice.c:307 do_splice_to+0x110/0x170 fs/splice.c:880 splice_direct_to_actor+0x242/0x820 fs/splice.c:952 do_splice_direct+0x2a7/0x3d0 fs/splice.c:1061 do_sendfile+0x5d5/0xe90 fs/read_write.c:1413 SYSC_sendfile64 fs/read_write.c:1468 [inline] SyS_sendfile64+0xbd/0x160 fs/read_write.c:1460 entry_SYSCALL_64_fastpath+0x1f/0x96 RIP: 0033:0x452879 RSP: 002b:00007f0c03363be8 EFLAGS: 00000212 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 0000000000758020 RCX: 0000000000452879 RDX: 00000000200ddff8 RSI: 0000000000000017 RDI: 0000000000000017 RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000100000001 R11: 0000000000000212 R12: 00000000006f2608 R13: 00000000ffffffff R14: 00007f0c033646d4 R15: 0000000000000000 Showing all locks held in the system: 2 locks held by khungtaskd/668: #0: (rcu_read_lock){....}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [] debug_show_all_locks+0xd3/0x400 kernel/locking/lockdep.c:4554 2 locks held by getty/3016: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3017: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3018: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3019: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3020: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3021: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 2 locks held by getty/3022: #0: (&tty->ldisc_sem){++++}, at: [] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [] n_tty_read+0x2f2/0x1a10 drivers/tty/n_tty.c:2131 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 668 Comm: khungtaskd Not tainted 4.14.0+ #190 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+0x37a/0x440 kernel/kthread.c:238 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:437 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 0 Comm: swapper/1 Not tainted 4.14.0+ #190 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 task: ffff8801da386300 task.stack: ffff8801da388000 RIP: 0010:llist_del_all include/linux/llist.h:234 [inline] RIP: 0010:sched_ttwu_pending+0x73/0x270 kernel/sched/core.c:1752 RSP: 0018:ffff8801db507cc0 EFLAGS: 00000046 RAX: ffffed003b6a0f9b RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8801da3874a0 RBP: ffff8801db507d60 R08: 0000000000000001 R09: ffff88021fff8048 R10: ffff88021fff8050 R11: ffff88021fff805d R12: ffff8801db525b40 R13: 1ffff1003b6a0f9b R14: dffffc0000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8801db500000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000009be000 CR3: 00000001d2f6b000 CR4: 00000000001406e0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: scheduler_ipi+0x24b/0x830 kernel/sched/core.c:1794 smp_reschedule_interrupt+0xe6/0x670 arch/x86/kernel/smp.c:277 reschedule_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:815 RIP: 0010:native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54 RSP: 0018:ffff8801da38fda8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff02 RAX: dffffc0000000000 RBX: 1ffff1003b471fb8 RCX: 0000000000000000 RDX: 1ffffffff0bd96ac RSI: 0000000000000001 RDI: ffffffff85ecb560 RBP: ffff8801da38fda8 R08: ffffffff85bdcae8 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000001 R13: ffff8801da38fe60 R14: ffffffff865df2e0 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:93 [inline] default_idle+0xbf/0x460 arch/x86/kernel/process.c:348 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:339 default_idle_call+0x36/0x90 kernel/sched/idle.c:98 cpuidle_idle_call kernel/sched/idle.c:156 [inline] do_idle+0x24a/0x3b0 kernel/sched/idle.c:246 cpu_startup_entry+0x18/0x20 kernel/sched/idle.c:351 start_secondary+0x2dd/0x3e0 arch/x86/kernel/smpboot.c:280 secondary_startup_64+0xa5/0xb0 arch/x86/kernel/head_64.S:237 Code: 88 60 80 4c 81 c7 00 f1 f1 f1 f1 c7 40 04 00 00 f2 f2 c7 40 08 f3 f3 f3 f3 65 4c 03 25 67 b0 b4 7e 31 db 49 87 9c 24 a0 0b 00 00 <48> 85 db 0f 84 60 01 00 00 48 8d 45 d8 4c 89 e7 48 89 85 70 ff