syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P11474/1:b..l P11865/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=114757, q=636 ncpus=2)
task:syz-executor    state:R  running task     stack:23680 pid:11865 tgid:11865 ppid:5218   flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_release+0x658/0xa30 kernel/locking/lockdep.c:5784
Code: 3c 3b 00 74 08 4c 89 f7 e8 35 de 8a 00 f6 84 24 91 00 00 00 02 75 77 41 f7 c5 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 4b c7 44 27 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000359f5e0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 1ffff920006b3ece RCX: ffffc9000359f603
RDX: 0000000000000000 RSI: ffffffff8c0ae6e0 RDI: ffffffff8c608d40
RBP: ffffc9000359f720 R08: ffffffff90186f2f R09: 1ffffffff2030de5
R10: dffffc0000000000 R11: fffffbfff2030de6 R12: 1ffff920006b3ec8
R13: 0000000000000246 R14: ffffc9000359f670 R15: dffffc0000000000
 rcu_lock_release include/linux/rcupdate.h:336 [inline]
 rcu_read_unlock include/linux/rcupdate.h:869 [inline]
 page_ext_put+0xa3/0xc0 mm/page_ext.c:550
 __set_page_owner+0x3f0/0x800 mm/page_owner.c:328
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x2e4c/0x2f10 mm/page_alloc.c:3439
 __alloc_pages_noprof+0x256/0x6c0 mm/page_alloc.c:4695
 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2263
 vm_area_alloc_pages mm/vmalloc.c:3584 [inline]
 __vmalloc_area_node mm/vmalloc.c:3653 [inline]
 __vmalloc_node_range_noprof+0xa40/0x1400 mm/vmalloc.c:3834
 vmalloc_user_noprof+0x74/0x80 mm/vmalloc.c:3988
 kcov_ioctl+0x59/0x640 kernel/kcov.c:715
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:907 [inline]
 __se_sys_ioctl+0xfe/0x170 fs/ioctl.c:893
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f69ce379abb
RSP: 002b:00007ffc244f53e0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007f69ce379abb
RDX: 0000000000040000 RSI: ffffffff80086301 RDI: 00000000000000dd
RBP: 00007f69ce516450 R08: 00000000000000da R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
task:syz-executor    state:R  running task     stack:20992 pid:11474 tgid:11474 ppid:1      flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:6851
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:page_ext_invalid mm/page_ext.c:245 [inline]
RIP: 0010:lookup_page_ext mm/page_ext.c:261 [inline]
RIP: 0010:page_ext_get+0x1ad/0x2a0 mm/page_ext.c:526
Code: 89 df e8 86 97 f3 ff 4c 8b 3b e8 fe 2d 71 ff 89 c3 31 ff 89 c6 e8 c3 50 8c ff 85 db 0f 84 ed 00 00 00 e8 76 4c 8c ff 44 89 fb <83> e3 01 31 ff 48 89 de e8 46 51 8c ff 4d 85 ff 74 1c 48 85 db 75
RSP: 0018:ffffc9000394f7c8 EFLAGS: 00000293
RAX: ffffffff8207403a RBX: 000000001b600000 RCX: ffff8880302f5a00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000080 R08: ffffffff8207402d R09: 1ffffffff283c908
R10: dffffc0000000000 R11: fffffbfff283c909 R12: 0000000000024ac0
R13: 0000000000000000 R14: ffffffff82073eb0 R15: ffff88801b600000
 __reset_page_owner+0x30/0x430 mm/page_owner.c:290
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0xd22/0xea0 mm/page_alloc.c:2612
 vfree+0x186/0x2e0 mm/vmalloc.c:3364
 kcov_put kernel/kcov.c:438 [inline]
 kcov_close+0x2b/0x50 kernel/kcov.c:534
 __fput+0x24c/0x8a0 fs/file_table.c:422
 task_work_run+0x251/0x310 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xa2f/0x27f0 kernel/exit.c:882
 do_group_exit+0x207/0x2c0 kernel/exit.c:1031
 get_signal+0x16a1/0x1740 kernel/signal.c:2917
 arch_do_signal_or_restart+0x96/0x860 arch/x86/kernel/signal.c:310
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline]
 __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline]
 syscall_exit_to_user_mode+0xc9/0x370 kernel/entry/common.c:218
 do_syscall_64+0x100/0x230 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5e07b7bd4c
RSP: 002b:00007ffc0a2486a0 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: 0000000000000024 RBX: 00007f5e08844620 RCX: 00007f5e07b7bd4c
RDX: 0000000000000024 RSI: 00007f5e08844670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffc0a2486f4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f5e08844670 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10582 jiffies! g114757 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:26448 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0x1800/0x4a60 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0x14b/0x320 kernel/sched/core.c:6621
 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2236
 kthread+0x2f2/0x390 kernel/kthread.c:389
 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:48 [inline]
NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:106 [inline]
NMI backtrace for cpu 0 skipped: idling at acpi_safe_halt+0x21/0x30 drivers/acpi/processor_idle.c:111