INFO: task syz-executor0:9795 blocked for more than 120 seconds. Not tainted 4.9.80-g550c01d #37 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D29040 9795 3889 0x20020004 ffff8801cc363000 ffff8801ce4af9c0 ffff8801beb09f80 ffff8801b3326000 ffff8801db321b98 ffff8801bd3275f0 ffffffff838a23db 0000000041b58ab3 ffffffff84193128 00ffffff8123be80 ffff8801db322468 ffff8801db322490 Call Trace: [] schedule+0x7f/0x1b0 kernel/sched/core.c:3550 [] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768 [] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5172 [] io_schedule include/linux/sched.h:460 [inline] [] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582 [] __wait_on_bit_lock+0xc2/0x1c0 kernel/sched/wait.c:421 [] __lock_page+0xff/0x160 mm/filemap.c:934 [] lock_page include/linux/pagemap.h:454 [inline] [] pagecache_get_page+0x436/0x710 mm/filemap.c:1216 [] grab_cache_page_write_begin+0x6c/0xa0 mm/filemap.c:2685 [] block_write_begin+0x3a/0x190 fs/buffer.c:2093 [] blkdev_write_begin+0x3c/0x50 fs/block_dev.c:330 [] generic_perform_write+0x261/0x500 mm/filemap.c:2741 [] __generic_file_write_iter+0x348/0x570 mm/filemap.c:2866 [] blkdev_write_iter+0x1bc/0x380 fs/block_dev.c:1718 [] new_sync_write fs/read_write.c:499 [inline] [] __vfs_write+0x4bf/0x680 fs/read_write.c:512 [] vfs_write+0x189/0x530 fs/read_write.c:560 [] SYSC_write fs/read_write.c:607 [inline] [] SyS_write+0xd9/0x1b0 fs/read_write.c:599 [] do_syscall_32_irqs_on arch/x86/entry/common.c:322 [inline] [] do_fast_syscall_32+0x2f7/0x890 arch/x86/entry/common.c:384 [] entry_SYSENTER_compat+0x74/0x83 arch/x86/entry/entry_64_compat.S:127 Showing all locks held in the system: 2 locks held by khungtaskd/515: #0: (rcu_read_lock){......}, at: [] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline] #0: (rcu_read_lock){......}, at: [] watchdog+0x125/0xa70 kernel/hung_task.c:239 #1: (tasklist_lock){.+.+..}, at: [] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336 1 lock held by rsyslogd/3658: #0: (&f->f_pos_lock){+.+.+.}, at: [] __fdget_pos+0x9f/0xc0 fs/file.c:781 2 locks held by getty/3786: #0: (&tty->ldisc_sem){++++++}, at: [] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367 #1: (&ldata->atomic_read_lock){+.+.+.}, at: [] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133 1 lock held by blkid/7097: #0: (&bdev->bd_mutex){+.+.+.}, at: [] __blkdev_put+0xbc/0x7e0 fs/block_dev.c:1579 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 515 Comm: khungtaskd Not tainted 4.9.80-g550c01d #37 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 ffff8801d8007d00 ffffffff81d94b69 0000000000000000 0000000000000000 0000000000000000 0000000000000001 ffffffff810bac60 ffff8801d8007d38 ffffffff81d9fc8d 0000000000000000 0000000000000000 ffff8801bd2a3418 Call Trace: [] __dump_stack lib/dump_stack.c:15 [inline] [] dump_stack+0xc1/0x128 lib/dump_stack.c:51 [] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99 [] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60 [] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37 [] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline] [] check_hung_task kernel/hung_task.c:125 [inline] [] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline] [] watchdog+0x6f0/0xa70 kernel/hung_task.c:239 [] kthread+0x26d/0x300 kernel/kthread.c:211 [] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:477 Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff838b20c6