syzbot


INFO: task hung in mmu_notifier_unregister

Status: closed as invalid on 2019/05/08 13:05
Subsystems: mm
[Documentation on labels]
First crash: 2212d, last: 2212d

Sample crash report:
INFO: task syz-executor.1:13186 blocked for more than 143 seconds.
      Not tainted 5.1.0-rc5-next-20190418 #28
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.1  D28648 13186  10113 0x80004002
Call Trace:
 context_switch kernel/sched/core.c:2817 [inline]
 __schedule+0x7d1/0x15c0 kernel/sched/core.c:3444
 schedule+0xa8/0x260 kernel/sched/core.c:3508
 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921
 synchronize_srcu+0x2dc/0x3e8 kernel/rcu/srcutree.c:999
 mmu_notifier_unregister+0x2cf/0x440 mm/mmu_notifier.c:372
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:746 [inline]
 kvm_put_kvm+0x553/0xc70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:771
 kvm_vm_release+0x44/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:782
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 exit_task_work include/linux/task_work.h:22 [inline]
 do_exit+0x90a/0x2fa0 kernel/exit.c:876
 do_group_exit+0x135/0x370 kernel/exit.c:980
 get_signal+0x399/0x1d50 kernel/signal.c:2578
 do_signal+0x87/0x1900 arch/x86/kernel/signal.c:818
 exit_to_usermode_loop+0x244/0x2c0 arch/x86/entry/common.c:163
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:276 [inline]
 do_syscall_64+0x57e/0x670 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x458c29
Code: Bad RIP value.
RSP: 002b:00007ff93b82dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: 0000000000000004 RBX: 0000000000000003 RCX: 0000000000458c29
RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000003
RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007ff93b82e6d4
R13: 00000000004c1788 R14: 00000000004d3f68 R15: 00000000ffffffff
INFO: task syz-executor.2:13194 blocked for more than 143 seconds.
      Not tainted 5.1.0-rc5-next-20190418 #28
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
syz-executor.2  D28384 13194   8062 0x00000004
Call Trace:
 context_switch kernel/sched/core.c:2817 [inline]
 __schedule+0x7d1/0x15c0 kernel/sched/core.c:3444
 schedule+0xa8/0x260 kernel/sched/core.c:3508
 schedule_timeout+0x717/0xc50 kernel/time/timer.c:1783
 do_wait_for_common kernel/sched/completion.c:83 [inline]
 __wait_for_common kernel/sched/completion.c:104 [inline]
 wait_for_common kernel/sched/completion.c:115 [inline]
 wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
 __synchronize_srcu+0x197/0x250 kernel/rcu/srcutree.c:921
 synchronize_srcu_expedited kernel/rcu/srcutree.c:946 [inline]
 synchronize_srcu+0x239/0x3e8 kernel/rcu/srcutree.c:997
 mmu_notifier_unregister+0x2cf/0x440 mm/mmu_notifier.c:372
 kvm_destroy_vm arch/x86/kvm/../../../virt/kvm/kvm_main.c:746 [inline]
 kvm_put_kvm+0x553/0xc70 arch/x86/kvm/../../../virt/kvm/kvm_main.c:771
 kvm_vm_release+0x44/0x60 arch/x86/kvm/../../../virt/kvm/kvm_main.c:782
 __fput+0x2e5/0x8d0 fs/file_table.c:278
 ____fput+0x16/0x20 fs/file_table.c:309
 task_work_run+0x14a/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:167
 prepare_exit_to_usermode arch/x86/entry/common.c:198 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:276 [inline]
 do_syscall_64+0x57e/0x670 arch/x86/entry/common.c:301
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x4129e1
Code: bb c8 00 00 00 ff 15 1e 6e 24 00 85 c0 89 c5 0f 85 7e fc ff ff e9 32 ff ff ff 66 66 66 66 66 66 2e 0f 1f 84 00 00 00 00 00 48 <89> 5c 24 d0 4c 89 6c 24 e8 48 89 d3 48 89 6c 24 d8 4c 89 64 24 e0
RSP: 002b:00007ffe4f8db5a0 EFLAGS: 00000293 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000005 RCX: 00000000004129e1
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 000000000073c900 R08: 0000000061d03d2a R09: 0000000061d03d2e
R10: 00007ffe4f8db670 R11: 0000000000000293 R12: 0000000000000001
R13: 000000000073c900 R14: 000000000005e351 R15: 000000000073bfac

Showing all locks held in the system:
3 locks held by kworker/0:1/12:
 #0: 00000000be0a8caf ((wq_completion)ipv6_addrconf){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline]
 #0: 00000000be0a8caf ((wq_completion)ipv6_addrconf){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 00000000be0a8caf ((wq_completion)ipv6_addrconf){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
 #0: 00000000be0a8caf ((wq_completion)ipv6_addrconf){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
 #0: 00000000be0a8caf ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline]
 #0: 00000000be0a8caf ((wq_completion)ipv6_addrconf){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
 #0: 00000000be0a8caf ((wq_completion)ipv6_addrconf){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2239
 #1: 00000000f7e9dcad ((addr_chk_work).work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2243
 #2: 00000000a54863d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76
1 lock held by khungtaskd/1023:
 #0: 0000000033014121 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5046
1 lock held by rsyslogd/7932:
 #0: 00000000cacda309 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801
2 locks held by getty/8022:
 #0: 00000000d0a735c7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000007eaf3358 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8023:
 #0: 0000000085caee3b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000001ccb418e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8024:
 #0: 00000000d838d46d (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000001844a2b3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8025:
 #0: 00000000ad680d19 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 0000000014e9e40b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8026:
 #0: 0000000057c622df (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 00000000ee195f44 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8027:
 #0: 00000000b95ac0f4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000007dd670bc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/8028:
 #0: 000000009629a302 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
 #1: 000000000a0517c3 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
3 locks held by kworker/1:3/8063:
1 lock held by syz-executor.1/10344:
 #0: 00000000a54863d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76
1 lock held by syz-executor.1/10761:
 #0: 00000000a54863d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76
1 lock held by syz-executor.1/11221:
 #0: 00000000c36d42ec (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:318 [inline]
 #0: 00000000c36d42ec (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x26f/0x5b0 kernel/rcu/tree_exp.h:790
5 locks held by kworker/u4:7/11637:
 #0: 000000005634df0a ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:224 [inline]
 #0: 000000005634df0a ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
 #0: 000000005634df0a ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
 #0: 000000005634df0a ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
 #0: 000000005634df0a ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline]
 #0: 000000005634df0a ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
 #0: 000000005634df0a ((wq_completion)netns){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2239
 #1: 000000003f74ceed (net_cleanup_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2243
 #2: 0000000004102f06 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x960 net/core/net_namespace.c:519
 #3: 00000000a54863d7 (rtnl_mutex){+.+.}, at: rtnl_lock+0x17/0x20 net/core/rtnetlink.c:76
 #4: 00000000c36d42ec (rcu_state.exp_mutex){+.+.}, at: exp_funnel_lock kernel/rcu/tree_exp.h:286 [inline]
 #4: 00000000c36d42ec (rcu_state.exp_mutex){+.+.}, at: synchronize_rcu_expedited+0x4ab/0x5b0 kernel/rcu/tree_exp.h:790

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

NMI backtrace for cpu 0
CPU: 0 PID: 1023 Comm: khungtaskd Not tainted 5.1.0-rc5-next-20190418 #28
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:254
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 0 to CPUs 1:

Crashes (1):
Time Kernel Commit Syzkaller Config Log Report Syz repro C repro VM info Assets (help?) Manager Title
2019/04/21 21:43 linux-next 3f018f4a019a b0e8efcb .config console log report ci-upstream-linux-next-kasan-gce-root
* Struck through repros no longer work on HEAD.