INFO: task syz-executor0:13727 blocked for more than 140 seconds. Not tainted 5.0.0-rc1-next-20190111 #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D25432 13727 7989 0x00000004 Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 wb_wait_for_completion+0x1e0/0x2d0 fs/fs-writeback.c:221 sync_inodes_sb+0x335/0x490 fs/fs-writeback.c:2417 sync_inodes_one_sb+0x57/0x70 fs/sync.c:74 iterate_supers+0x149/0x290 fs/super.c:723 ksys_sync+0xdf/0x1d0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f59535ccc78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 000000000073bf08 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f59535cd6d4 R13: 00000000004c4272 R14: 00000000004db338 R15: 00000000ffffffff INFO: task syz-executor0:13735 blocked for more than 140 seconds. Not tainted 5.0.0-rc1-next-20190111 #10 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor0 D25400 13735 7989 0x00000004 Call Trace: context_switch kernel/sched/core.c:2834 [inline] __schedule+0x897/0x1e60 kernel/sched/core.c:3475 schedule+0xfe/0x350 kernel/sched/core.c:3519 wb_wait_for_completion+0x1e0/0x2d0 fs/fs-writeback.c:221 sync_inodes_sb+0x335/0x490 fs/fs-writeback.c:2417 sync_inodes_one_sb+0x57/0x70 fs/sync.c:74 iterate_supers+0x149/0x290 fs/super.c:723 ksys_sync+0xdf/0x1d0 fs/sync.c:113 __ia32_sys_sync+0xe/0x20 fs/sync.c:124 do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x457ec9 Code: Bad RIP value. RSP: 002b:00007f595358ac78 EFLAGS: 00000246 ORIG_RAX: 00000000000000a2 RAX: ffffffffffffffda RBX: 000000000073c048 RCX: 0000000000457ec9 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 000000000073c040 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f595358b6d4 R13: 00000000004c4272 R14: 00000000004db338 R15: 00000000ffffffff Showing all locks held in the system: 4 locks held by kworker/u4:3/311: 1 lock held by khungtaskd/1040: #0: 000000001f99e7fb (rcu_read_lock){....}, at: debug_show_all_locks+0xc6/0x41d kernel/locking/lockdep.c:4408 1 lock held by rsyslogd/7864: #0: 00000000dc7c84bc (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1b3/0x1f0 fs/file.c:796 2 locks held by getty/7954: #0: 000000003ba331d7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cada53f1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7955: #0: 000000009bb7ce7a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000801e7d48 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7956: #0: 000000001d6de7fd (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000cf5c1eb0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7957: #0: 000000007d96e1df (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004577e853 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7958: #0: 0000000099d96465 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000045382d4e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7959: #0: 00000000a0e5db64 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000008801cc40 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 2 locks held by getty/7960: #0: 000000004ab708e3 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000706a9f94 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x30a/0x1eb0 drivers/tty/n_tty.c:2154 1 lock held by syz-executor0/13727: #0: 0000000043d9e643 (&type->s_umount_key#54){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721 1 lock held by syz-executor0/13735: #0: 0000000043d9e643 (&type->s_umount_key#54){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 5.0.0-rc1-next-20190111 #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x1db/0x2d0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1be/0x236 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:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:203 [inline] watchdog+0xbbb/0x1170 kernel/hung_task.c:287 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 311 Comm: kworker/u4:3 Not tainted 5.0.0-rc1-next-20190111 #10 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: writeback wb_workfn (flush-7:0) RIP: 0010:xa_entry include/linux/xarray.h:1004 [inline] RIP: 0010:xas_descend+0x199/0x500 lib/xarray.c:198 Code: b5 40 ff ff ff 85 f6 74 2a e8 43 b5 8f f9 0f b6 35 4f 21 66 02 31 ff 40 88 b5 40 ff ff ff e8 6e b6 8f f9 0f b6 b5 40 ff ff ff <40> 84 f6 0f 84 21 02 00 00 e8 19 b5 8f f9 48 8d 7b 18 48 b8 00 00 RSP: 0018:ffff8880a8e665b0 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880a8e66770 RCX: ffffffff87f27772 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff8880a8e66678 R08: ffff8880a8e585c0 R09: ffffed1015cc5b90 R10: ffffed1015cc5b8f R11: ffff8880ae62dc7b R12: 0000000000000000 R13: ffff88804e86c340 R14: ffff88808a81d1c2 R15: ffff8880a8e66650 FS: 0000000000000000(0000) GS:ffff8880ae600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 0000000093445000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: xas_load+0xef/0x150 lib/xarray.c:234 find_get_entry+0x353/0x1090 mm/filemap.c:1476 pagecache_get_page+0xe5/0x1070 mm/filemap.c:1582 find_get_page_flags include/linux/pagemap.h:279 [inline] __find_get_block_slow fs/buffer.c:205 [inline] __find_get_block fs/buffer.c:1331 [inline] __find_get_block+0x615/0xf20 fs/buffer.c:1325 __getblk_slow fs/buffer.c:1058 [inline] __getblk_gfp+0x3c2/0x1140 fs/buffer.c:1357 __bread_gfp+0x2f/0x300 fs/buffer.c:1391 sb_bread include/linux/buffer_head.h:307 [inline] fat_clusters_flush+0x127/0x3c0 fs/fat/misc.c:70 fat_write_inode fs/fat/inode.c:905 [inline] fat_write_inode+0x111/0x190 fs/fat/inode.c:897 write_inode fs/fs-writeback.c:1176 [inline] __writeback_single_inode+0xef1/0x1620 fs/fs-writeback.c:1375 writeback_sb_inodes+0x762/0x1260 fs/fs-writeback.c:1580 __writeback_inodes_wb+0x16d/0x3d0 fs/fs-writeback.c:1649 wb_writeback+0xa2d/0xf70 fs/fs-writeback.c:1758 wb_check_start_all fs/fs-writeback.c:1882 [inline] wb_do_writeback fs/fs-writeback.c:1908 [inline] wb_workfn+0xe52/0x16f0 fs/fs-writeback.c:1942 process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153 worker_thread+0x143/0x14a0 kernel/workqueue.c:2296 kthread+0x357/0x430 kernel/kthread.c:247 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352