Buffer I/O error on dev loop0, logical block 0, lost async page write audit: type=1400 audit(1521109021.596:137): avc: denied { map } for pid=14775 comm="sh" path="/bin/dash" dev="sda1" ino=1473 scontext=system_u:system_r:insmod_t:s0-s0:c0.c1023 tcontext=system_u:object_r:file_t:s0 tclass=file permissive=1 INFO: task blkid:14474 blocked for more than 120 seconds. Not tainted 4.16.0-rc5+ #354 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. blkid D21120 14474 4216 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 io_schedule+0x1c/0x70 kernel/sched/core.c:5115 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] write_cache_pages+0xb33/0x14b0 mm/page-writeback.c:2206 generic_writepages+0xe9/0x150 mm/page-writeback.c:2325 blkdev_writepages+0x1d/0x30 fs/block_dev.c:1954 do_writepages+0xff/0x170 mm/page-writeback.c:2340 __filemap_fdatawrite_range+0x32f/0x460 mm/filemap.c:444 __filemap_fdatawrite mm/filemap.c:452 [inline] filemap_fdatawrite mm/filemap.c:457 [inline] filemap_write_and_wait+0x59/0xd0 mm/filemap.c:616 __sync_blockdev fs/block_dev.c:448 [inline] sync_blockdev.part.30+0x50/0x70 fs/block_dev.c:457 sync_blockdev fs/block_dev.c:444 [inline] __blkdev_put+0x18b/0x760 fs/block_dev.c:1781 blkdev_put+0x85/0x4f0 fs/block_dev.c:1850 blkdev_close+0x8b/0xb0 fs/block_dev.c:1857 __fput+0x327/0x7e0 fs/file_table.c:209 ____fput+0x15/0x20 fs/file_table.c:243 task_work_run+0x199/0x270 kernel/task_work.c:113 tracehook_notify_resume include/linux/tracehook.h:191 [inline] exit_to_usermode_loop+0x275/0x2f0 arch/x86/entry/common.c:166 prepare_exit_to_usermode arch/x86/entry/common.c:196 [inline] syscall_return_slowpath arch/x86/entry/common.c:265 [inline] do_syscall_64+0x6ec/0x940 arch/x86/entry/common.c:292 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x7f8d0f1272b0 RSP: 002b:00007ffe34c8aa48 EFLAGS: 00000246 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00007f8d0f1272b0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000028 R09: 0000000001680000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000d0f030 R13: 0000000000000000 R14: 0000000000000003 R15: 0000000000000005 Showing all locks held in the system: 2 locks held by khungtaskd/798: #0: (rcu_read_lock){....}, at: [<00000000e11279e6>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000e11279e6>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<00000000e5a32038>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 3 locks held by kworker/u4:3/1668: #0: ((wq_completion)"writeback"){+.+.}, at: [<0000000020a429be>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<0000000020a429be>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<0000000020a429be>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<0000000020a429be>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<0000000092e0d6a9>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (&type->s_umount_key#27){.+.+}, at: [<00000000388b8432>] trylock_super+0x20/0x100 fs/super.c:395 2 locks held by getty/4206: #0: (&tty->ldisc_sem){++++}, at: [<000000009c0c7595>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e30f091d>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4207: #0: (&tty->ldisc_sem){++++}, at: [<000000009c0c7595>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e30f091d>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4208: #0: (&tty->ldisc_sem){++++}, at: [<000000009c0c7595>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e30f091d>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4209: #0: (&tty->ldisc_sem){++++}, at: [<000000009c0c7595>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e30f091d>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4210: #0: (&tty->ldisc_sem){++++}, at: [<000000009c0c7595>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e30f091d>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4211: #0: (&tty->ldisc_sem){++++}, at: [<000000009c0c7595>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e30f091d>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4212: #0: (&tty->ldisc_sem){++++}, at: [<000000009c0c7595>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000e30f091d>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 1 lock held by blkid/14474: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000b4634b0d>] __blkdev_put+0xbc/0x760 fs/block_dev.c:1775 1 lock held by syz-executor4/14741: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000e49af8bf>] __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 1 lock held by syz-executor4/14743: #0: (&bdev->bd_mutex){+.+.}, at: [<00000000e49af8bf>] __blkdev_get+0x176/0x13b0 fs/block_dev.c:1458 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 798 Comm: khungtaskd Not tainted 4.16.0-rc5+ #354 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 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54