syzbot


INFO: task hung in blkdev_fsync

Status: closed as dup on 2018/02/14 15:37
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+2c56c0ca42f9e7bf1aef@syzkaller.appspotmail.com
First crash: 2480d, last: 2416d
Duplicate of
Title Repro Cause bisect Fix bisect Count Last Reported
INFO: task hung in sync_blockdev fs 25 2421d 2479d
Discussions (1)
Title Replies (including bot) Last reply
INFO: task hung in blkdev_fsync 1 (2) 2018/02/14 15:36
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-44 INFO: task hung in blkdev_fsync 42 2403d 2480d 0/2 auto-closed as invalid on 2019/02/22 13:49
upstream INFO: task hung in blkdev_fsync (2) kasan mm 1 1085d 1085d 0/28 closed as invalid on 2022/02/08 09:40
android-49 INFO: task hung in blkdev_fsync 61 2329d 2479d 0/3 auto-closed as invalid on 2019/02/22 15:27

Sample crash report:
Buffer I/O error on dev loop0, logical block 3, async page read
INFO: task syz-executor2:20962 blocked for more than 120 seconds.
      Not tainted 4.16.0+ #19
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor2   D24328 20962   4524 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2848 [inline]
 __schedule+0x807/0x1e40 kernel/sched/core.c:3490
 schedule+0xef/0x430 kernel/sched/core.c:3549
 io_schedule+0x1c/0x70 kernel/sched/core.c:5169
 wait_on_page_bit_common+0x4dc/0x770 mm/filemap.c:1099
 wait_on_page_bit mm/filemap.c:1132 [inline]
 wait_on_page_writeback include/linux/pagemap.h:546 [inline]
 __filemap_fdatawait_range+0x31e/0x4c0 mm/filemap.c:533
 file_write_and_wait_range+0xf0/0x130 mm/filemap.c:756
 blkdev_fsync+0x6b/0xd0 fs/block_dev.c:623
 vfs_fsync_range+0x140/0x220 fs/sync.c:197
 vfs_fsync fs/sync.c:211 [inline]
 do_fsync+0x52/0xa0 fs/sync.c:221
 SYSC_fdatasync fs/sync.c:234 [inline]
 SyS_fdatasync+0x19/0x20 fs/sync.c:232
 do_syscall_64+0x29e/0x9d0 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x42/0xb7
RIP: 0033:0x455259
RSP: 002b:00007fd1fd3b7c68 EFLAGS: 00000246 ORIG_RAX: 000000000000004b
RAX: ffffffffffffffda RBX: 00007fd1fd3b86d4 RCX: 0000000000455259
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000014
RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff
R13: 0000000000000097 R14: 00000000006f3ec8 R15: 0000000000000000

Showing all locks held in the system:
3 locks held by kworker/u4:0/6:
 #0: 00000000da725080 ((wq_completion)"writeback"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline]
 #0: 00000000da725080 ((wq_completion)"writeback"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000da725080 ((wq_completion)"writeback"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 00000000da725080 ((wq_completion)"writeback"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:57 [inline]
 #0: 00000000da725080 ((wq_completion)"writeback"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 00000000da725080 ((wq_completion)"writeback"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 00000000da725080 ((wq_completion)"writeback"){+.+.}, at: process_one_work+0xaef/0x1b50 kernel/workqueue.c:2116
 #1: 0000000053a20744 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0xb46/0x1b50 kernel/workqueue.c:2120
 #2: 000000000d2ddb20 (&type->s_umount_key#35){++++}, at: trylock_super+0x22/0x110 fs/super.c:395
2 locks held by khungtaskd/888:
 #0: 000000003f8c64dd (rcu_read_lock){....}, at: check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline]
 #0: 000000003f8c64dd (rcu_read_lock){....}, at: watchdog+0x1ff/0xf60 kernel/hung_task.c:249
 #1: 00000000dbdd2e96 (tasklist_lock){.+.+}, at: debug_show_all_locks+0xde/0x34a kernel/locking/lockdep.c:4470
2 locks held by getty/4449:
 #0: 0000000097e8840b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000633a51c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4450:
 #0: 00000000561dab29 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000001f4f21c5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4451:
 #0: 0000000071e94742 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000458b340c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4452:
 #0: 0000000002be1e76 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000a113b565 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4453:
 #0: 00000000371a1d93 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000e47b1051 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4454:
 #0: 000000007c4b8302 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000006571234e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131
2 locks held by getty/4455:
 #0: 0000000004761c19 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000c4ecce93 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x321/0x1cc0 drivers/tty/n_tty.c:2131

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

NMI backtrace for cpu 1
CPU: 1 PID: 888 Comm: khungtaskd Not tainted 4.16.0+ #19
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+0x1b9/0x294 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold.4+0x19/0xce lib/nmi_backtrace.c:103
 nmi_trigger_cpumask_backtrace+0x151/0x192 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+0xc10/0xf60 kernel/hung_task.c:249
 kthread+0x345/0x410 kernel/kthread.c:238
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:411
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

Crashes (29):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/04/11 17:36 upstream b284d4d5a678 8b8de427 .config console log report ci-upstream-kasan-gce
2018/04/03 22:25 upstream f2d285669aae 676bd07e .config console log report ci-upstream-kasan-gce-root
2018/04/03 21:47 upstream f2d285669aae 676bd07e .config console log report ci-upstream-kasan-gce-root
2018/04/02 19:03 upstream 0adb32858b0b 676bd07e .config console log report ci-upstream-kasan-gce-root
2018/04/01 01:44 upstream 10b84daddbec 0174c6c8 .config console log report ci-upstream-kasan-gce-root
2018/03/30 16:00 upstream c2a9838452a4 d47f0ed6 .config console log report ci-upstream-kasan-gce
2018/03/24 07:58 upstream 99fec39e7725 2e9d9054 .config console log report ci-upstream-kasan-gce
2018/03/21 10:43 upstream 3215b9d57a2c 113a43ff .config console log report ci-upstream-kasan-gce
2018/03/13 04:07 upstream fc6eabbbf8ef f505ca4b .config console log report ci-upstream-kasan-gce
2018/03/06 03:20 upstream 094b58e1040a aef0b792 .config console log report ci-upstream-kasan-gce
2018/03/05 21:48 upstream 661e50bc8532 bbd5104f .config console log report ci-upstream-kasan-gce
2018/03/05 16:38 upstream 661e50bc8532 bbd5104f .config console log report ci-upstream-kasan-gce
2018/03/04 23:28 upstream e64b9562ba28 2c6f473e .config console log report ci-upstream-kasan-gce
2018/02/28 11:54 upstream f3afe530d644 05b5a32c .config console log report ci-upstream-kasan-gce
2018/02/08 14:22 upstream 581e400ff935 9fb5ec43 .config console log report ci-upstream-kasan-gce
2018/02/06 20:09 upstream e237f98a9c13 66c15deb .config console log report ci-upstream-kasan-gce
2018/04/09 10:15 upstream f2d285669aae f13fb445 .config console log report ci-upstream-kasan-gce-386
2018/04/07 02:04 upstream f2d285669aae d613535f .config console log report ci-upstream-kasan-gce-386
2018/04/04 05:36 upstream f2d285669aae 676bd07e .config console log report ci-upstream-kasan-gce-386
2018/03/26 11:02 upstream 3eb2ce825ea1 e033c1f1 .config console log report ci-upstream-kasan-gce-386
2018/03/22 08:18 upstream 3215b9d57a2c 95c88d7a .config console log report ci-upstream-kasan-gce-386
2018/03/22 00:10 upstream 3215b9d57a2c 95c88d7a .config console log report ci-upstream-kasan-gce-386
2018/03/18 14:56 upstream 8f5fd927c3a7 08dacaa0 .config console log report ci-upstream-kasan-gce-386
2018/03/18 04:05 upstream 8f5fd927c3a7 08dacaa0 .config console log report ci-upstream-kasan-gce-386
2018/03/14 20:23 upstream 3032f8c504d2 08dacaa0 .config console log report ci-upstream-kasan-gce-386
2018/03/05 00:14 upstream e64b9562ba28 2c6f473e .config console log report ci-upstream-kasan-gce-386
2018/03/02 17:35 upstream 5d60e057d127 2c6f473e .config console log report ci-upstream-kasan-gce-386
2018/02/28 01:14 upstream f3afe530d644 05b5a32c .config console log report ci-upstream-kasan-gce-386
2018/02/08 06:09 upstream 581e400ff935 9fb5ec43 .config console log report ci-upstream-kasan-gce-386
* Struck through repros no longer work on HEAD.