syzbot


INFO: task hung in nmi_cpu_backtrace

Status: auto-closed as invalid on 2019/02/22 10:26
Subsystems: fs
[Documentation on labels]
Reported-by: syzbot+86b9f1a1cf3db69d0855@syzkaller.appspotmail.com
First crash: 2123d, last: 2121d
Similar bugs (3)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-49 INFO: task hung in nmi_cpu_backtrace 3 2089d 2265d 0/3 auto-closed as invalid on 2019/02/22 13:59
upstream INFO: task hung in nmi_cpu_backtrace (2) serial 1 198d 198d 0/26 auto-obsoleted due to no activity on 2024/01/08 02:36
linux-4.14 INFO: task hung in nmi_cpu_backtrace 1 1574d 1574d 0/1 auto-closed as invalid on 2020/05/02 01:19

Sample crash report:
kworker/dying (276) used greatest stack depth: 12776 bytes left
INFO: task syz-executor4:18981 blocked for more than 120 seconds.
      Not tainted 4.18.0-rc3+ #33
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.

Showing all locks held in the system:
2 locks held by kworker/0:1/25:
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124
 #1: 0000000092303d3f ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128
2 locks held by kworker/1:1/27:
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: __write_once_size include/linux/compiler.h:215 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:40 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:59 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: set_work_data kernel/workqueue.c:617 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:644 [inline]
 #0: 000000008e2cce76 ((wq_completion)"events"){+.+.}, at: process_one_work+0xb44/0x1ba0 kernel/workqueue.c:2124
 #1: 00000000c4e0dde8 ((work_completion)(&smc->tcp_listen_work)){+.+.}, at: process_one_work+0xb9b/0x1ba0 kernel/workqueue.c:2128
1 lock held by khungtaskd/900:
 #0: 00000000cd17448c (rcu_read_lock){....}, at: debug_show_all_locks+0xd0/0x428 kernel/locking/lockdep.c:4461
1 lock held by rsyslogd/4435:
 #0: 000000002864294e (&f->f_pos_lock){+.+.}, at: __fdget_pos+0x1bb/0x200 fs/file.c:766
2 locks held by getty/4525:
 #0: 00000000d66ea930 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000dbde5f75 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4526:
 #0: 0000000017cee0aa (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000b6a820b2 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4527:
 #0: 00000000efb7d997 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 00000000b17a4b7c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4528:
 #0: 00000000cc67ad89 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 0000000055ae238c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4529:
 #0: 000000000f527055 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000009ffd58ec (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4530:
 #0: 00000000fcb739b2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000007ea95d27 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140
2 locks held by getty/4531:
 #0: 000000000c668fd5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365
 #1: 000000007e6064af (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x335/0x1ce0 drivers/tty/n_tty.c:2140

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

NMI backtrace for cpu 0
CPU: 0 PID: 900 Comm: khungtaskd Not tainted 4.18.0-rc3+ #33
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+0x1c9/0x2b4 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_uninterruptible_tasks kernel/hung_task.c:196 [inline]
 watchdog+0x9c4/0xf80 kernel/hung_task.c:252
 kthread+0x345/0x410 kernel/kthread.c:240
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:412
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at native_safe_halt+0x6/0x10 arch/x86/include/asm/irqflags.h:54

Crashes (7):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2018/07/04 17:07 upstream fc36def997cf 317fc8ea .config console log report ci-upstream-kasan-gce-386
2018/07/04 13:33 upstream fc36def997cf 317fc8ea .config console log report ci-upstream-kasan-gce-386
2018/07/05 09:10 net-next-old 6fcf9b1d4d6c f525fd72 .config console log report ci-upstream-net-kasan-gce
2018/07/04 09:53 net-next-old 2bdea157b999 317fc8ea .config console log report ci-upstream-net-kasan-gce
2018/07/04 03:30 net-next-old 44a4c4698ee8 317fc8ea .config console log report ci-upstream-net-kasan-gce
2018/07/03 12:12 net-next-old 00f553660a7f 317fc8ea .config console log report ci-upstream-net-kasan-gce
2018/07/03 12:03 net-next-old 00f553660a7f 317fc8ea .config console log report ci-upstream-net-kasan-gce
* Struck through repros no longer work on HEAD.