syzbot


INFO: task hung in lru_add_drain_all_cpuslocked

Status: auto-closed as invalid on 2019/08/01 14:28
Reported-by: syzbot+e4dd66f6577b22277656@syzkaller.appspotmail.com
First crash: 2106d, last: 1958d
Similar bugs (1)
Kernel Title Repro Cause bisect Fix bisect Count Last Reported Patched Status
android-414 INFO: task hung in lru_add_drain_all_cpuslocked (2) 1 1749d 1749d 0/1 auto-closed as invalid on 2019/12/28 09:27

Sample crash report:
INFO: task syz-executor5:6552 blocked for more than 140 seconds.
      Not tainted 4.14.97+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor5   D29048  6552   3106 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3490
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893
 lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704
 lru_add_drain_all+0xf/0x20 mm/swap.c:730
 do_mlock+0x90/0x5d0 mm/mlock.c:673
 SYSC_mlock2 mm/mlock.c:726 [inline]
 SyS_mlock2+0x49/0x70 mm/mlock.c:716
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289
INFO: task syz-executor0:6549 blocked for more than 140 seconds.
      Not tainted 4.14.97+ #1
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor0   D28176  6549   1841 0x00000004
Call Trace:
 schedule+0x92/0x1c0 kernel/sched/core.c:3490
 schedule_preempt_disabled+0x13/0x20 kernel/sched/core.c:3548
 __mutex_lock_common kernel/locking/mutex.c:833 [inline]
 __mutex_lock+0x559/0x1430 kernel/locking/mutex.c:893
 lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704
 lru_add_drain_all+0xf/0x20 mm/swap.c:730
 do_mlock+0x90/0x5d0 mm/mlock.c:673
 SYSC_mlock2 mm/mlock.c:726 [inline]
 SyS_mlock2+0x49/0x70 mm/mlock.c:716
 do_syscall_64+0x19b/0x4b0 arch/x86/entry/common.c:289

Showing all locks held in the system:
1 lock held by khungtaskd/23:
 #0:  (tasklist_lock){.+.?}, at: [<ffffffffa2ffff4c>] debug_show_all_locks+0x7c/0x21a kernel/locking/lockdep.c:4541
1 lock held by rsyslogd/1626:
 #0:  (&f->f_pos_lock){+.+.}, at: [<ffffffffa33b99c6>] __fdget_pos+0xa6/0xc0 fs/file.c:768
2 locks held by getty/1754:
 #0:  (&tty->ldisc_sem){++++}, at: [<ffffffffa3b37052>] tty_ldisc_ref_wait+0x22/0x80 drivers/tty/tty_ldisc.c:275
 #1:  (&ldata->atomic_read_lock){+.+.}, at: [<ffffffffa3b32477>] n_tty_read+0x1f7/0x1700 drivers/tty/n_tty.c:2156
2 locks held by syz-executor5/6552:
 #0:  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffffa325bc8a>] get_online_cpus include/linux/cpu.h:138 [inline]
 #0:  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffffa325bc8a>] lru_add_drain_all+0xa/0x20 mm/swap.c:729
 #1:  (lock#4){+.+.}, at: [<ffffffffa325b8cc>] lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704
2 locks held by syz-executor0/6549:
 #0:  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffffa325bc8a>] get_online_cpus include/linux/cpu.h:138 [inline]
 #0:  (cpu_hotplug_lock.rw_sem){++++}, at: [<ffffffffa325bc8a>] lru_add_drain_all+0xa/0x20 mm/swap.c:729
 #1:  (lock#4){+.+.}, at: [<ffffffffa325b8cc>] lru_add_drain_all_cpuslocked+0x6c/0x420 mm/swap.c:704

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

NMI backtrace for cpu 0
CPU: 0 PID: 23 Comm: khungtaskd Not tainted 4.14.97+ #1
Call Trace:
 __dump_stack lib/dump_stack.c:17 [inline]
 dump_stack+0xb9/0x10e lib/dump_stack.c:53
 nmi_cpu_backtrace.cold+0x47/0x86 lib/nmi_backtrace.c:101
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1 skipped: idling at pc 0xffffffffa46508a2

Crashes (2):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/02/02 14:27 android-4.14 80d7b06534fa c198d5dd .config console log report ci-android-414-kasan-gce-root
2018/09/07 08:38 android-4.14 b859aa7d7a0c e30d3b52 .config console log report ci-android-414-kasan-gce-root
* Struck through repros no longer work on HEAD.