syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1):
 P10142/1:b..l
 P10120/1:b..l

rcu: 	(detected by 0, t=10502 jiffies, g=68137, q=283 ncpus=2)
task:syz.4.580       state:R
  running task     stack:27008 pid:10120 tgid:10118 ppid:9743   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:preempt_count arch/x86/include/asm/preempt.h:26 [inline]
RIP: 0010:check_kcov_mode kernel/kcov.c:182 [inline]
RIP: 0010:write_comp_data+0x11/0x90 kernel/kcov.c:245
Code: cc cc cc cc 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 49 89 d2 49 89 f8 49 89 f1 65 48 8b 15 4f ff 77 7e <65> 8b 05 50 ff 77 7e a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00
RSP: 0018:ffffc90004b3f6d8 EFLAGS: 00000246

RAX: 0000000000000003 RBX: ffff88801d6647f8 RCX: ffffffff81f63a8f
RDX: ffff8880265a0000 RSI: 0000000000000000 RDI: 0000000000000005
RBP: ffff88801d6647b0 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: dffffc0000000000
 __page_table_check_zero+0x19f/0x370 mm/page_table_check.c:156
 page_table_check_free include/linux/page_table_check.h:41 [inline]
 free_pages_prepare mm/page_alloc.c:1102 [inline]
 free_unref_folios+0xa07/0x1390 mm/page_alloc.c:2667
 folios_put_refs+0x560/0x760 mm/swap.c:1039
 folio_batch_release include/linux/pagevec.h:101 [inline]
 shmem_undo_range+0x5a1/0x1160 mm/shmem.c:1023
 shmem_fallocate+0xd70/0xfa0 mm/shmem.c:3340
 vfs_fallocate+0x459/0xf90 fs/open.c:333
 ksys_fallocate fs/open.c:356 [inline]
 __do_sys_fallocate fs/open.c:364 [inline]
 __se_sys_fallocate fs/open.c:362 [inline]
 __x64_sys_fallocate+0xd5/0x140 fs/open.c:362
 do_syscall_x64 arch/x86/entry/common.c:52 [inline]
 do_syscall_64+0xcd/0x250 arch/x86/entry/common.c:83
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe0fa97def9
RSP: 002b:00007fe0fb769038 EFLAGS: 00000246
 ORIG_RAX: 000000000000011d
RAX: ffffffffffffffda RBX: 00007fe0fab36058 RCX: 00007fe0fa97def9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000a
RBP: 00007fe0fa9f0b76 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008000001 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fe0fab36058 R15: 00007ffebcb99b88
 </TASK>
task:syz.2.847       state:R
  running task     stack:25632 pid:10142 tgid:10139 ppid:6245   flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:6851
 irqentry_exit+0x36/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:check_kcov_mode kernel/kcov.c:184 [inline]
RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:245
Code: 8b 05 50 ff 77 7e a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 1c 16 00 00 85 c0 74 4f <8b> 82 f8 15 00 00 83 f8 03 75 44 48 8b 82 00 16 00 00 8b 92 fc 15
RSP: 0018:ffffc90004c3f6b8 EFLAGS: 00000246

RAX: 0000000080000000 RBX: ffffc90004c3f740 RCX: ffffffff813cff46
RDX: ffff88802809da00 RSI: 0000000000000000 RDI: 0000000000000005
RBP: 0000000000000001 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: ffffc90004c3f740
R13: ffffffff817774c0 R14: ffffc90004c3f800 R15: ffff88802809da00
 unwind_next_frame+0x46/0x23a0 arch/x86/kernel/unwind_orc.c:475
 arch_stack_walk+0x100/0x170 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x95/0xd0 kernel/stacktrace.c:122
 save_stack+0x162/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x8d/0x400 mm/page_owner.c:297
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1101 [inline]
 free_unref_page+0x64a/0xe40 mm/page_alloc.c:2619
 vfree+0x181/0x7a0 mm/vmalloc.c:3367
 kcov_put kernel/kcov.c:438 [inline]
 kcov_put+0x2a/0x40 kernel/kcov.c:434
 kcov_close+0xd/0x20 kernel/kcov.c:534
 __fput+0x3f6/0xb60 fs/file_table.c:431
 task_work_run+0x14e/0x250 kernel/task_work.c:228
 exit_task_work include/linux/task_work.h:40 [inline]
 do_exit+0xaa3/0x2bb0 kernel/exit.c:882
 do_group_exit+0xd3/0x2a0 kernel/exit.c:1031
 get_signal+0x25fb/0x2770 kernel/signal.c:2917
 arch_do_signal_or_restart+0x90/0x7e0 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+0x150/0x2a0 kernel/entry/common.c:218
 do_syscall_64+0xda/0x250 arch/x86/entry/common.c:89
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb46fd7def9
RSP: 002b:00007fb470afa038 EFLAGS: 00000246
 ORIG_RAX: 0000000000000136
RAX: 00000000003ffb80 RBX: 00007fb46ff36058 RCX: 00007fb46fd7def9
RDX: 0000000000000002 RSI: 0000000020008400 RDI: 00000000000003d3
RBP: 00007fb46fdf0b76 R08: 0000000000000286 R09: 0000000000000000
R10: 0000000020008640 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007fb46ff36058 R15: 00007fff5b297388
 </TASK>
rcu: rcu_preempt kthread starved for 10491 jiffies! g68137 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:25872 pid:17    tgid:17    ppid:2      flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5188 [inline]
 __schedule+0xe37/0x5490 kernel/sched/core.c:6529
 __schedule_loop kernel/sched/core.c:6606 [inline]
 schedule+0xe7/0x350 kernel/sched/core.c:6621
 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2581
 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:2034
 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:2236
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 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:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.11.0-syzkaller-02574-ga430d95c5efa #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/06/2024
RIP: 0010:native_irq_disable arch/x86/include/asm/irqflags.h:37 [inline]
RIP: 0010:arch_local_irq_disable arch/x86/include/asm/irqflags.h:92 [inline]
RIP: 0010:acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 65 48 8b 05 78 a2 eb 74 48 8b 00 a8 08 75 0c 66 90 0f 00 2d 68 56 a4 00 fb f4 <fa> c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8da07d70 EFLAGS: 00000246

RAX: 0000000000004000 RBX: 0000000000000001 RCX: ffffffff8b181979
RDX: 0000000000000001 RSI: ffff88801d69b800 RDI: ffff88801d69b864
RBP: ffff88801d69b864 R08: 0000000000000001 R09: ffffed1017106fd9
R10: ffff8880b8837ecb R11: 0000000000000000 R12: ffff888020fc0800
R13: ffffffff8e9faa20 R14: 0000000000000000 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8880b8800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd6b7f3098 CR3: 000000002f5cc000 CR4: 00000000003506f0
Call Trace:
 <IRQ>
 </IRQ>
 <TASK>
 acpi_idle_enter+0xc5/0x160 drivers/acpi/processor_idle.c:702
 cpuidle_enter_state+0xaa/0x4f0 drivers/cpuidle/cpuidle.c:264
 cpuidle_enter+0x4e/0xa0 drivers/cpuidle/cpuidle.c:385
 cpuidle_idle_call kernel/sched/idle.c:230 [inline]
 do_idle+0x313/0x3f0 kernel/sched/idle.c:326
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:424
 rest_init+0x16b/0x2b0 init/main.c:747
 start_kernel+0x3e4/0x4d0 init/main.c:1105
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:507
 x86_64_start_kernel+0xb2/0xc0 arch/x86/kernel/head64.c:488
 common_startup_64+0x13e/0x148
 </TASK>