INFO: rcu_sched self-detected stall on CPU 0-....: (124999 ticks this GP) idle=fde/1/4611686018427387906 softirq=36814/36814 fqs=31225 (t=125000 jiffies g=19333 c=19332 q=279) NMI backtrace for cpu 0 CPU: 0 PID: 14430 Comm: syz-executor0 Not tainted 4.16.0-rc7+ #368 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_single_cpu_backtrace include/linux/nmi.h:156 [inline] rcu_dump_cpu_stacks+0x186/0x1de kernel/rcu/tree.c:1375 print_cpu_stall kernel/rcu/tree.c:1524 [inline] check_cpu_stall.isra.61+0xbb8/0x15b0 kernel/rcu/tree.c:1592 __rcu_pending kernel/rcu/tree.c:3361 [inline] rcu_pending kernel/rcu/tree.c:3423 [inline] rcu_check_callbacks+0x238/0xd20 kernel/rcu/tree.c:2763 update_process_times+0x30/0x60 kernel/time/timer.c:1636 tick_sched_handle+0x85/0x160 kernel/time/tick-sched.c:162 tick_sched_timer+0x42/0x120 kernel/time/tick-sched.c:1194 __run_hrtimer kernel/time/hrtimer.c:1349 [inline] __hrtimer_run_queues+0x39c/0xec0 kernel/time/hrtimer.c:1411 hrtimer_interrupt+0x2a5/0x6f0 kernel/time/hrtimer.c:1469 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1025 [inline] smp_apic_timer_interrupt+0x14a/0x700 arch/x86/kernel/apic/apic.c:1050 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:857 RIP: 0010:bitmap_set include/linux/bitmap.h:365 [inline] RIP: 0010:__bitmap_parselist+0x308/0x4b0 lib/bitmap.c:616 RSP: 0018:ffff8801d520f6d8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff12 RAX: 0000000000010000 RBX: 0000000000000001 RCX: ffffffff82afaa75 RDX: 0000000000000000 RSI: 0000000000000009 RDI: ffff8801b1df6da0 RBP: ffff8801d520f750 R08: ffffed00363bedb5 R09: ffff8801b1df6da0 R10: 0000000000000001 R11: ffffed00363bedb4 R12: 0000000000000009 R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000 bitmap_parselist+0x3a/0x50 lib/bitmap.c:628 cpulist_parse include/linux/cpumask.h:639 [inline] update_cpumask kernel/cgroup/cpuset.c:974 [inline] cpuset_write_resmask+0x1694/0x2850 kernel/cgroup/cpuset.c:1724 cgroup_file_write+0x2ae/0x710 kernel/cgroup/cgroup.c:3429 kernfs_fop_write+0x2bc/0x440 fs/kernfs/file.c:316 __vfs_write+0xef/0x970 fs/read_write.c:480 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454889 RSP: 002b:00007f52ae330c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f52ae3316d4 RCX: 0000000000454889 RDX: 0000000000000002 RSI: 0000000020000080 RDI: 0000000000000015 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000006a2 R14: 00000000006fbfd0 R15: 0000000000000000 INFO: task syz-executor6:6353 blocked for more than 120 seconds. Not tainted 4.16.0-rc7+ #368 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. syz-executor6 D22160 6353 6320 0x00000000 Call Trace: context_switch kernel/sched/core.c:2862 [inline] __schedule+0x8fb/0x1ec0 kernel/sched/core.c:3440 schedule+0xf5/0x430 kernel/sched/core.c:3499 schedule_timeout+0x1a3/0x230 kernel/time/timer.c:1777 do_wait_for_common kernel/sched/completion.c:86 [inline] __wait_for_common kernel/sched/completion.c:107 [inline] wait_for_common kernel/sched/completion.c:118 [inline] wait_for_completion+0x415/0x770 kernel/sched/completion.c:139 __wait_rcu_gp+0x221/0x340 kernel/rcu/update.c:414 synchronize_sched.part.64+0xac/0x100 kernel/rcu/tree.c:3212 synchronize_sched+0x76/0xf0 kernel/rcu/tree.c:3213 synchronize_rcu include/linux/rcupdate.h:94 [inline] namespace_unlock+0x1a1/0x1f0 fs/namespace.c:1423 do_umount+0x3f8/0xda0 fs/namespace.c:1619 SYSC_umount fs/namespace.c:1714 [inline] SyS_umount+0x355/0x460 fs/namespace.c:1683 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x457297 RSP: 002b:0000000000a3c958 EFLAGS: 00000202 ORIG_RAX: 00000000000000a6 RAX: ffffffffffffffda RBX: 0000000000000064 RCX: 0000000000457297 RDX: 0000000000000000 RSI: 0000000000000002 RDI: 0000000000a3dac0 RBP: 0000000000a3dac0 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000005 R11: 0000000000000202 R12: 00000000017aa980 R13: 0000000000000000 R14: 0000000000000006 R15: 000000000001d2c0 Showing all locks held in the system: 2 locks held by khungtaskd/868: #0: (rcu_read_lock){....}, at: [<00000000589ecac6>] check_hung_uninterruptible_tasks kernel/hung_task.c:175 [inline] #0: (rcu_read_lock){....}, at: [<00000000589ecac6>] watchdog+0x1c5/0xd60 kernel/hung_task.c:249 #1: (tasklist_lock){.+.+}, at: [<000000001a06dd25>] debug_show_all_locks+0xd3/0x3d0 kernel/locking/lockdep.c:4470 4 locks held by rs:main Q:Reg/4312: #0: (&f->f_pos_lock){+.+.}, at: [<000000003836f365>] __fdget_pos+0x12b/0x190 fs/file.c:765 #1: (sb_writers#4){.+.+}, at: [<00000000228345a6>] file_start_write include/linux/fs.h:2709 [inline] #1: (sb_writers#4){.+.+}, at: [<00000000228345a6>] vfs_write+0x407/0x510 fs/read_write.c:543 #2: (&sb->s_type->i_mutex_key#10){++++}, at: [<000000004485913d>] inode_trylock include/linux/fs.h:733 [inline] #2: (&sb->s_type->i_mutex_key#10){++++}, at: [<000000004485913d>] ext4_file_write_iter+0x21f/0x10c0 fs/ext4/file.c:232 #3: (jbd2_handle){++++}, at: [<00000000baf89e6a>] start_this_handle+0x488/0x1080 fs/jbd2/transaction.c:385 2 locks held by getty/4404: #0: (&tty->ldisc_sem){++++}, at: [<00000000efa4be6c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070201b03>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4405: #0: (&tty->ldisc_sem){++++}, at: [<00000000efa4be6c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070201b03>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4406: #0: (&tty->ldisc_sem){++++}, at: [<00000000efa4be6c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070201b03>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4407: #0: (&tty->ldisc_sem){++++}, at: [<00000000efa4be6c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070201b03>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4408: #0: (&tty->ldisc_sem){++++}, at: [<00000000efa4be6c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070201b03>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4409: #0: (&tty->ldisc_sem){++++}, at: [<00000000efa4be6c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070201b03>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 2 locks held by getty/4410: #0: (&tty->ldisc_sem){++++}, at: [<00000000efa4be6c>] ldsem_down_read+0x37/0x40 drivers/tty/tty_ldsem.c:365 #1: (&ldata->atomic_read_lock){+.+.}, at: [<0000000070201b03>] n_tty_read+0x2ef/0x1a40 drivers/tty/n_tty.c:2131 1 lock held by syz-executor0/14440: #0: (&f->f_pos_lock){+.+.}, at: [<000000003836f365>] __fdget_pos+0x12b/0x190 fs/file.c:765 4 locks held by syz-executor0/14443: #0: (&f->f_pos_lock){+.+.}, at: [<000000003836f365>] __fdget_pos+0x12b/0x190 fs/file.c:765 #1: (sb_writers#11){.+.+}, at: [<00000000228345a6>] file_start_write include/linux/fs.h:2709 [inline] #1: (sb_writers#11){.+.+}, at: [<00000000228345a6>] vfs_write+0x407/0x510 fs/read_write.c:543 #2: (&of->mutex){+.+.}, at: [<000000004b9930dd>] kernfs_fop_write+0x208/0x440 fs/kernfs/file.c:307 #3: (cpuset_mutex){+.+.}, at: [<00000000b1ccf315>] cpuset_write_resmask+0x165/0x2850 kernel/cgroup/cpuset.c:1712 1 lock held by syz-executor0/14445: #0: (&f->f_pos_lock){+.+.}, at: [<000000003836f365>] __fdget_pos+0x12b/0x190 fs/file.c:765 1 lock held by syz-executor1/14436: #0: (lock#6){+.+.}, at: [<00000000b92937ed>] lru_add_drain_all+0xb2/0x540 mm/swap.c:683 1 lock held by syz-executor1/14444: #0: (lock#6){+.+.}, at: [<00000000b92937ed>] lru_add_drain_all+0xb2/0x540 mm/swap.c:683 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 868 Comm: khungtaskd Not tainted 4.16.0-rc7+ #368 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:17 [inline] dump_stack+0x194/0x24d lib/dump_stack.c:53 nmi_cpu_backtrace+0x1d2/0x210 lib/nmi_backtrace.c:103 nmi_trigger_cpumask_backtrace+0x123/0x180 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+0x90c/0xd60 kernel/hung_task.c:249 kthread+0x33c/0x400 kernel/kthread.c:238 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:406 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 14430 Comm: syz-executor0 Not tainted 4.16.0-rc7+ #368 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:get_current arch/x86/include/asm/current.h:15 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0xa/0x50 kernel/kcov.c:100 RSP: 0018:ffff8801d520f680 EFLAGS: 00000286 RAX: ffff8801d30f0540 RBX: fffffffffffffe00 RCX: 0000000000000009 RDX: 0000000000010000 RSI: 0000000000000009 RDI: ffff8801b1df6da0 RBP: ffff8801d520f6c8 R08: ffffed00363bedb5 R09: ffff8801b1df6da0 R10: 0000000000000001 R11: ffffed00363bedb4 R12: ffffffffffffffff R13: 0000000000000000 R14: ffff8801b1df6da0 R15: 0000000000000000 FS: 00007f52ae331700(0000) GS:ffff8801db200000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000a3eaf8 CR3: 00000001b4856005 CR4: 00000000001606f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: bitmap_set include/linux/bitmap.h:365 [inline] __bitmap_parselist+0x310/0x4b0 lib/bitmap.c:616 bitmap_parselist+0x3a/0x50 lib/bitmap.c:628 cpulist_parse include/linux/cpumask.h:639 [inline] update_cpumask kernel/cgroup/cpuset.c:974 [inline] cpuset_write_resmask+0x1694/0x2850 kernel/cgroup/cpuset.c:1724 cgroup_file_write+0x2ae/0x710 kernel/cgroup/cgroup.c:3429 kernfs_fop_write+0x2bc/0x440 fs/kernfs/file.c:316 __vfs_write+0xef/0x970 fs/read_write.c:480 vfs_write+0x189/0x510 fs/read_write.c:544 SYSC_write fs/read_write.c:589 [inline] SyS_write+0xef/0x220 fs/read_write.c:581 do_syscall_64+0x281/0x940 arch/x86/entry/common.c:287 entry_SYSCALL_64_after_hwframe+0x42/0xb7 RIP: 0033:0x454889 RSP: 002b:00007f52ae330c68 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 00007f52ae3316d4 RCX: 0000000000454889 RDX: 0000000000000002 RSI: 0000000020000080 RDI: 0000000000000015 RBP: 000000000072bea0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000000006a2 R14: 00000000006fbfd0 R15: 0000000000000000 Code: 32 fd ff ff 48 8b bd d0 fe ff ff e8 51 47 38 00 e9 c3 fc ff ff 90 90 90 90 90 90 90 90 90 90 90 90 55 65 48 8b 04 25 c0 ed 01 00 <48> 89 e5 65 8b 15 1c 24 90 7e 81 e2 00 01 1f 00 48 8b 4d 08 75