syzbot


INFO: task hung in collapse_huge_page (2)

Status: auto-closed as invalid on 2019/10/25 09:41
Reported-by: syzbot+@syzkaller.appspotmail.com
First crash: 1351d, last: 1302d
similar bugs (1):
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
upstream INFO: task hung in collapse_huge_page 352 1601d 1674d 0/24 closed as dup on 2018/06/11 10:57

Sample crash report:
INFO: task khugepaged:1050 blocked for more than 143 seconds.
      Not tainted 5.1.0+ #2
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
khugepaged      D29008  1050      2 0x80004002
Call Trace:
 context_switch kernel/sched/core.c:2817 [inline]
 __schedule+0x7d1/0x1580 kernel/sched/core.c:3444
 schedule+0xa8/0x260 kernel/sched/core.c:3508
 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:585 [inline]
 rwsem_down_write_failed+0x7a1/0xc60 kernel/locking/rwsem-xadd.c:617
 __down_write kernel/locking/rwsem.h:227 [inline]
 down_write+0x93/0xa0 kernel/locking/rwsem.c:68
 collapse_huge_page+0x22b/0x3f60 mm/khugepaged.c:1006
 khugepaged_scan_pmd mm/khugepaged.c:1215 [inline]
 khugepaged_scan_mm_slot mm/khugepaged.c:1725 [inline]
 khugepaged_do_scan mm/khugepaged.c:1806 [inline]
 khugepaged+0x28c3/0x3f40 mm/khugepaged.c:1851
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Showing all locks held in the system:
2 locks held by kworker/u4:2/27:
 #0: 00000000021ee84b (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline]
 #0: 00000000021ee84b (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1580 kernel/sched/core.c:3396
 #1: 00000000775358ce (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline]
 #1: 00000000775358ce (rcu_read_lock){....}, at: update_curr+0x2ce/0x8a0 kernel/sched/fair.c:842
1 lock held by khungtaskd/1043:
 #0: 00000000775358ce (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5148
1 lock held by khugepaged/1050:
 #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: collapse_huge_page+0x22b/0x3f60 mm/khugepaged.c:1006
2 locks held by rs:main Q:Reg/7620:
 #0: 00000000037ccb31 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801
 #1: 0000000031fda072 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2825 [inline]
 #1: 0000000031fda072 (sb_writers#3){.+.+}, at: vfs_write+0x429/0x580 fs/read_write.c:548
1 lock held by rsyslogd/7622:
 #0: 000000003982f90b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801
2 locks held by getty/7712:
 #0: 000000001259c200 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000b685ff57 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7713:
 #0: 000000008d6cdd62 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000001ab375ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7714:
 #0: 00000000468246cf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000306de473 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7715:
 #0: 00000000e3e88028 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000aa7c396c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7716:
 #0: 00000000fdf9b841 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000002f5ab3fc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7717:
 #0: 000000005b261b3b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000002574170e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7718:
 #0: 00000000104d4dc9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000bc0bc82b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
1 lock held by syz-fuzzer/7734:
 #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: __do_sys_madvise mm/madvise.c:838 [inline]
 #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: __se_sys_madvise mm/madvise.c:802 [inline]
 #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: __x64_sys_madvise+0x2bb/0x15f0 mm/madvise.c:802
1 lock held by syz-fuzzer/7737:
1 lock held by syz-executor.3/14717:
 #0: 00000000d9fa00ae (&type->s_umount_key#30){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721
2 locks held by syz-executor.3/14739:
 #0: 00000000d9fa00ae (&type->s_umount_key#30){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721
 #1: 00000000021ee84b (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline]
 #1: 00000000021ee84b (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1580 kernel/sched/core.c:3396
1 lock held by syz-executor.5/14782:
 #0: 00000000696eb4da (&bdev->bd_mutex){+.+.}, at: iterate_bdevs+0xca/0x294 fs/block_dev.c:2216
2 locks held by syz-executor.3/14812:
 #0: 00000000d9fa00ae (&type->s_umount_key#30){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721
 #1: 00000000021ee84b (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline]
 #1: 00000000021ee84b (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1580 kernel/sched/core.c:3396

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

NMI backtrace for cpu 1
CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.1.0+ #2
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+0x172/0x1f0 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:204 [inline]
 watchdog+0x9b7/0xec0 kernel/hung_task.c:288
 kthread+0x357/0x430 kernel/kthread.c:253
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0:

Crashes (4):
Manager Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Title
ci-upstream-kasan-gce-root 2019/05/07 21:53 upstream 8ff468c29e9a a7383bfa .config log report
ci-upstream-kasan-gce 2019/05/04 03:43 upstream a4ccb5f9dc6c d28f4ce5 .config log report
ci-upstream-kasan-gce-root 2019/05/03 23:17 upstream a4ccb5f9dc6c d28f4ce5 .config log report
ci-upstream-kasan-gce 2019/03/19 00:07 upstream 9e98c678c2d6 46264c32 .config log report
* Struck through repros no longer work on HEAD.