buffer_io_error: 11 callbacks suppressed Buffer I/O error on dev loop0, logical block 3, async page read INFO: task syz-executor3:29661 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #278 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor3 D23472 29661 4470 0x20020004 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] pagecache_get_page+0x674/0xba0 mm/filemap.c:1553 grab_cache_page_write_begin+0x6c/0xa0 mm/filemap.c:3088 block_write_begin+0xa6/0x2e0 fs/buffer.c:2086 blkdev_write_begin+0x3c/0x50 fs/block_dev.c:584 generic_perform_write+0x28f/0x600 mm/filemap.c:3138 __generic_file_write_iter+0x366/0x5b0 mm/filemap.c:3263 blkdev_write_iter+0x207/0x3e0 fs/block_dev.c:1908 call_write_iter include/linux/fs.h:1782 [inline] do_iter_readv_writev+0x55c/0x830 fs/read_write.c:653 do_iter_write+0x154/0x540 fs/read_write.c:932 vfs_iter_write+0x77/0xb0 fs/read_write.c:945 iter_file_splice_write+0x7db/0xf30 fs/splice.c:749 do_splice_from fs/splice.c:851 [inline] direct_splice_actor+0x125/0x180 fs/splice.c:1018 splice_direct_to_actor+0x2c1/0x820 fs/splice.c:973 do_splice_direct+0x29b/0x3c0 fs/splice.c:1061 do_sendfile+0x5c9/0xe80 fs/read_write.c:1413 C_SYSC_sendfile fs/read_write.c:1489 [inline] compat_SyS_sendfile+0xea/0x1a0 fs/read_write.c:1478 do_syscall_32_irqs_on arch/x86/entry/common.c:330 [inline] do_fast_syscall_32+0x3ec/0xf9f arch/x86/entry/common.c:392 entry_SYSENTER_compat+0x70/0x7f arch/x86/entry/entry_64_compat.S:139 RIP: 0023:0xf7f1cc99 RSP: 002b:00000000f771809c EFLAGS: 00000286 ORIG_RAX: 00000000000000bb RAX: ffffffffffffffda RBX: 0000000000000015 RCX: 0000000000000017 RDX: 00000000200ddff8 RSI: 0000000002000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 Showing all locks held in the system: 3 locks held by kworker/u4:2/28: #0: ((wq_completion)"writeback"){+.+.}, at: [<000000007e929e5c>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000007e929e5c>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000007e929e5c>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"writeback"){+.+.}, at: [<000000007e929e5c>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: [<0000000076738299>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (&type->s_umount_key#33){.+.+}, at: [<00000000a051f12d>] trylock_super+0x20/0x100 fs/super.c:395 2 locks held by khungtaskd/868: #0: (rcu_read_lock){....}, at: [<000000004c4a7342>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<000000004c4a7342>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<0000000088f5601b>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 1 lock held by rsyslogd/4302: #0: (&f->f_pos_lock){+.+.}, at: [<00000000367509ba>] __fdget_pos+0x12b/0x190 fs/file.c:765 2 locks held by getty/4392: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6087e96>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000f7a70bbc>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4393: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6087e96>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000f7a70bbc>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4394: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6087e96>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000f7a70bbc>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4395: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6087e96>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000f7a70bbc>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4396: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6087e96>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000f7a70bbc>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4397: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6087e96>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000f7a70bbc>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4398: #0: (&tty->ldisc_sem){++++}, at: [<00000000d6087e96>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<00000000f7a70bbc>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 4 locks held by kworker/0:3/5699: #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000007e929e5c>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000007e929e5c>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000007e929e5c>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"cgroup_destroy"){+.+.}, at: [<000000007e929e5c>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&css->destroy_work)#3){+.+.}, at: [<0000000076738299>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cpu_hotplug_lock.rw_sem){++++}, at: [<000000005e91f72c>] get_online_cpus include/linux/cpu.h:124 [inline] #2: (cpu_hotplug_lock.rw_sem){++++}, at: [<000000005e91f72c>] memcg_destroy_kmem_caches+0xf/0x80 mm/slab_common.c:771 #3: (slab_mutex){+.+.}, at: [<00000000ac5034ab>] memcg_destroy_kmem_caches+0x24/0x80 mm/slab_common.c:774 4 locks held by kworker/0:10/11488: #0: ((wq_completion)"memcg_kmem_cache"){+.+.}, at: [<000000007e929e5c>] work_static include/linux/workqueue.h:198 [inline] #0: ((wq_completion)"memcg_kmem_cache"){+.+.}, at: [<000000007e929e5c>] set_work_data kernel/workqueue.c:619 [inline] #0: ((wq_completion)"memcg_kmem_cache"){+.+.}, at: [<000000007e929e5c>] set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline] #0: ((wq_completion)"memcg_kmem_cache"){+.+.}, at: [<000000007e929e5c>] process_one_work+0xb12/0x1bb0 kernel/workqueue.c:2084 #1: ((work_completion)(&cw->work)){+.+.}, at: [<0000000076738299>] process_one_work+0xb89/0x1bb0 kernel/workqueue.c:2088 #2: (cpu_hotplug_lock.rw_sem){++++}, at: [<0000000039b5a212>] get_online_cpus include/linux/cpu.h:124 [inline] #2: (cpu_hotplug_lock.rw_sem){++++}, at: [<0000000039b5a212>] memcg_create_kmem_cache+0x16/0x170 mm/slab_common.c:619 #3: (slab_mutex){+.+.}, at: [<00000000d5db61d9>] memcg_create_kmem_cache+0x24/0x170 mm/slab_common.c:622 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 868 Comm: khungtaskd Not tainted 4.16.0-rc7+ #278 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 CPU: 0 PID: 11491 Comm: kworker/0:13 Not tainted 4.16.0-rc7+ #278 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:lookup_object lib/debugobjects.c:131 [inline] RIP: 0010:debug_object_deactivate+0x18b/0x560 lib/debugobjects.c:502 RSP: 0018:ffff8801a1e1f480 EFLAGS: 00000802 RAX: 0000000000000082 RBX: ffff8801b31985b0 RCX: dffffc0000000000 RDX: ffffffff883d0a88 RSI: 1ffff100366330b6 RDI: ffff8801b31985c8 RBP: ffff8801a1e1f550 R08: 1ffff100343c3dcd R09: 000000000000000c R10: ffff8801a1e1f330 R11: 0000000000000000 R12: 1ffff100343c3e94 R13: 0000000000000021 R14: ffff8801a1e1f520 R15: ffffffff89326cc8 FS: 0000000000000000(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000130 CR3: 0000000007a22002 CR4: 00000000001606f0 DR0: 0000000020000000 DR1: 0000000020000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000600 Call Trace: debug_work_deactivate kernel/workqueue.c:498 [inline] process_one_work+0x550/0x1bb0 kernel/workqueue.c:2050 worker_thread+0x223/0x1990 kernel/workqueue.c:2247 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Code: 0f 85 a0 02 00 00 48 8b 1b 41 bd 01 00 00 00 48 85 db 0f 84 b1 00 00 00 48 b9 00 00 00 00 00 fc ff df eb 1d 48 89 de 48 c1 ee 03 <80> 3c 0e 00 0f 85 ce 02 00 00 48 8b 1b 48 85 db 0f 84 88 00 00