syzbot


INFO: task hung in sync_blockdev

Status: auto-closed as invalid on 2019/02/22 12:31
First crash: 2248d, last: 2211d
Similar bugs (2)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 INFO: task hung in sync_blockdev 12 2182d 2214d 0/2 auto-closed as invalid on 2019/02/22 13:59
upstream INFO: task hung in sync_blockdev fs 25 2199d 2257d 0/26 auto-closed as invalid on 2019/02/22 10:34

Sample crash report:
Buffer I/O error on dev loop0, logical block 10, lost async page write
INFO: task syz-executor6:6335 blocked for more than 120 seconds.
      Not tainted 4.9.90-gdd1e37e #66
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor6   D26192  6335   3875 0x00000006
 ffff8801cfe66000 0000000000000000 ffff8801bf736f40 ffff8801d9b73000
 ffff8801db321b98 ffff8801c26e7530 ffffffff838a75cb 0000000041b58ab3
 ffffffff84193d90 00ffffff8123aaf0 ffff8801db322468 ffff8801db322490
Call Trace:
 [<ffffffff838a8b6f>] schedule+0x7f/0x1b0 kernel/sched/core.c:3551
 [<ffffffff838b4b2c>] schedule_timeout+0x56c/0x10b0 kernel/time/timer.c:1768
 [<ffffffff838a6d7e>] io_schedule_timeout+0x1be/0x390 kernel/sched/core.c:5173
 [<ffffffff838a9fe9>] io_schedule include/linux/sched.h:460 [inline]
 [<ffffffff838a9fe9>] bit_wait_io+0x19/0xa0 kernel/sched/wait.c:582
 [<ffffffff838a96c7>] __wait_on_bit+0x57/0x120 kernel/sched/wait.c:383
 [<ffffffff814316e4>] wait_on_page_bit+0xf4/0x140 mm/filemap.c:802
 [<ffffffff814318f1>] wait_on_page_writeback include/linux/pagemap.h:526 [inline]
 [<ffffffff814318f1>] __filemap_fdatawait_range+0x1c1/0x2b0 mm/filemap.c:453
 [<ffffffff81431a05>] filemap_fdatawait_range+0x25/0x50 mm/filemap.c:483
 [<ffffffff8143a635>] filemap_fdatawait mm/filemap.c:533 [inline]
 [<ffffffff8143a635>] filemap_write_and_wait+0xf5/0x120 mm/filemap.c:551
 [<ffffffff8162cb80>] __sync_blockdev fs/block_dev.c:194 [inline]
 [<ffffffff8162cb80>] sync_blockdev.part.28+0x50/0x70 fs/block_dev.c:203
 [<ffffffff8162d1a4>] sync_blockdev fs/block_dev.c:190 [inline]
 [<ffffffff8162d1a4>] __blkdev_put+0x184/0x7e0 fs/block_dev.c:1585
 [<ffffffff8162e5d5>] blkdev_put+0x85/0x550 fs/block_dev.c:1663
 [<ffffffff8162eb2b>] blkdev_close+0x8b/0xb0 fs/block_dev.c:1670
 [<ffffffff81574b8c>] __fput+0x28c/0x6e0 fs/file_table.c:208
 [<ffffffff81575065>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff81196fe5>] task_work_run+0x115/0x190 kernel/task_work.c:116
 [<ffffffff81167c00>] get_signal+0x11b0/0x14e0 kernel/signal.c:2147
 [<ffffffff81052c87>] do_signal+0x87/0x19f0 arch/x86/kernel/signal.c:807
 [<ffffffff81004ff1>] exit_to_usermode_loop+0xe1/0x120 arch/x86/entry/common.c:157
 [<ffffffff810066cf>] prepare_exit_to_usermode arch/x86/entry/common.c:191 [inline]
 [<ffffffff810066cf>] syscall_return_slowpath arch/x86/entry/common.c:260 [inline]
 [<ffffffff810066cf>] do_syscall_64+0x36f/0x490 arch/x86/entry/common.c:287
 [<ffffffff838b8493>] entry_SYSCALL_64_after_swapgs+0x5d/0xdb

Showing all locks held in the system:
3 locks held by kworker/u4:2/45:
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118af42>] work_static include/linux/workqueue.h:186 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118af42>] set_work_data kernel/workqueue.c:617 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118af42>] set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0:  ("writeback"){.+.+.+}, at: [<ffffffff8118af42>] process_one_work+0x6f2/0x1610 kernel/workqueue.c:2085
 #1:  ((&(&wb->dwork)->work)){+.+.+.}, at: [<ffffffff8118af7c>] process_one_work+0x72c/0x1610 kernel/workqueue.c:2089
 #2:  (&type->s_umount_key#22){.+.+..}, at: [<ffffffff815790a0>] trylock_super+0x20/0x100 fs/super.c:393
2 locks held by khungtaskd/515:
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372185>] check_hung_uninterruptible_tasks kernel/hung_task.c:168 [inline]
 #0:  (rcu_read_lock){......}, at: [<ffffffff81372185>] watchdog+0x125/0xa70 kernel/hung_task.c:239
 #1:  (tasklist_lock){.+.+..}, at: [<ffffffff81236c50>] debug_show_all_locks+0x70/0x280 kernel/locking/lockdep.c:4336
2 locks held by getty/3782:
 #0:  (&tty->ldisc_sem){++++++}, at: [<ffffffff838b66a2>] ldsem_down_read+0x32/0x40 drivers/tty/tty_ldsem.c:367
 #1:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8200a6a4>] n_tty_read+0x1f4/0x16c0 drivers/tty/n_tty.c:2133
1 lock held by syz-executor6/6335:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162d0dc>] __blkdev_put+0xbc/0x7e0 fs/block_dev.c:1579
1 lock held by syz-executor6/6352:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff816309b8>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:1976
1 lock held by syz-executor6/6374:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff816309b8>] iterate_bdevs+0xc8/0x260 fs/block_dev.c:1976
1 lock held by blkid/6383:
 #0:  (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff8162d90c>] __blkdev_get+0x10c/0xd50 fs/block_dev.c:1268

=============================================

NMI backtrace for cpu 0
CPU: 0 PID: 515 Comm: khungtaskd Not tainted 4.9.90-gdd1e37e #66
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
 ffff8801d85b7d00 ffffffff81d94ee9 0000000000000000 0000000000000000
 0000000000000000 0000000000000001 ffffffff810bb920 ffff8801d85b7d38
 ffffffff81da000d 0000000000000000 0000000000000000 ffff8801cffc9c18
Call Trace:
 [<ffffffff81d94ee9>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81d94ee9>] dump_stack+0xc1/0x128 lib/dump_stack.c:51
 [<ffffffff81da000d>] nmi_cpu_backtrace+0xfd/0x120 lib/nmi_backtrace.c:99
 [<ffffffff81da0147>] nmi_trigger_cpumask_backtrace+0x117/0x190 lib/nmi_backtrace.c:60
 [<ffffffff810bba14>] arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:37
 [<ffffffff81372750>] trigger_all_cpu_backtrace include/linux/nmi.h:58 [inline]
 [<ffffffff81372750>] check_hung_task kernel/hung_task.c:125 [inline]
 [<ffffffff81372750>] check_hung_uninterruptible_tasks kernel/hung_task.c:182 [inline]
 [<ffffffff81372750>] watchdog+0x6f0/0xa70 kernel/hung_task.c:239
 [<ffffffff8119bf4d>] kthread+0x26d/0x300 kernel/kthread.c:211
 [<ffffffff838b865c>] ret_from_fork+0x5c/0x70 arch/x86/entry/entry_64.S:373
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffff838b7116

Crashes (6):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/03/25 17:23 https://android.googlesource.com/kernel/common android-4.9 dd1e37e64645 e033c1f1 .config console log report ci-android-49-kasan-gce
2018/03/11 12:15 https://android.googlesource.com/kernel/common android-4.9 00db063b0f88 36d1c454 .config console log report ci-android-49-kasan-gce
2018/02/26 20:26 https://android.googlesource.com/kernel/common android-4.9 a9d027374a35 b370d4a7 .config console log report ci-android-49-kasan-gce
2018/03/24 12:45 https://android.googlesource.com/kernel/common android-4.9 e34e3186e9e3 2e9d9054 .config console log report ci-android-49-kasan-gce-386
2018/03/09 13:59 https://android.googlesource.com/kernel/common android-4.9 00db063b0f88 36d1c454 .config console log report ci-android-49-kasan-gce-386
2018/02/16 22:35 https://android.googlesource.com/kernel/common android-4.9 a25ea24f7b7d c8b3f7c1 .config console log report ci-android-49-kasan-gce-386
* Struck through repros no longer work on HEAD.