vkms_vblank_simulate: vblank timer overrun
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P24221/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=116645, q=465 ncpus=2)
task:syz.4.4772 state:R running task stack:25600 pid:24221 tgid:24219 ppid:15939 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6855
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7182
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:68
Code: c7 c7 b8 80 8a 8b e8 6c 5e ba 00 e9 e8 fb ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90003406f28 EFLAGS: 00000202
RAX: ffffffff81858ea0 RBX: 0000000000000001 RCX: ffffc90003408000
RDX: ffffc90003407a01 RSI: ffffc90003407af0 RDI: ffffc90003407af0
RBP: ffffc90003406fe8 R08: ffffffff912db642 R09: 00000000ffffffff
R10: ffff888030392ff0 R11: 000000000001390d R12: ffffc90003406ff0
R13: ffffc90003406fa0 R14: ffffc90003407af8 R15: ffffc90003406fd4
deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
unwind_next_frame+0xb8f/0x20a0 arch/x86/kernel/unwind_orc.c:585
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x160/0x1f0 mm/page_owner.c:156
__reset_page_owner+0x84/0x1a0 mm/page_owner.c:311
reset_page_owner include/linux/page_owner.h:25 [inline]
free_pages_prepare mm/page_alloc.c:1394 [inline]
free_unref_folios+0xa15/0x1600 mm/page_alloc.c:2958
folios_put_refs+0x4be/0x750 mm/swap.c:1002
folio_batch_release include/linux/pagevec.h:101 [inline]
shmem_undo_range+0x58f/0x1140 mm/shmem.c:1119
shmem_truncate_range mm/shmem.c:1231 [inline]
shmem_evict_inode+0x3a1/0xbe0 mm/shmem.c:1359
evict+0x3c2/0xad0 fs/inode.c:837
iput_final fs/inode.c:1951 [inline]
iput.part.0+0x621/0x1190 fs/inode.c:2003
iput+0x35/0x40 fs/inode.c:1966
dentry_unlink_inode+0x29c/0x480 fs/dcache.c:467
__dentry_kill+0x1d0/0x600 fs/dcache.c:670
dput.part.0+0x4b1/0x9b0 fs/dcache.c:912
dput+0x1f/0x30 fs/dcache.c:902
__fput+0x51c/0xb70 fs/file_table.c:476
task_work_run+0x150/0x240 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x87f/0x2bd0 kernel/exit.c:973
do_group_exit+0xd3/0x2a0 kernel/exit.c:1114
get_signal+0x2671/0x26d0 kernel/signal.c:3034
arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x8c/0x540 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x4ee/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f1b6978f749
RSP: 002b:00007f1b6a67c038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007f1b699e6090 RCX: 00007f1b6978f749
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000003
RBP: 00007f1b69813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f1b699e6128 R14: 00007f1b699e6090 R15: 00007fff31fc2a08
rcu: rcu_preempt kthread starved for 10240 jiffies! g116645 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:27480 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5248 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6855
__schedule_loop kernel/sched/core.c:6937 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6952
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 76 76 02 e9 d3 2f 03 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 d3 2b 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e007df8 EFLAGS: 000002c2
RAX: 00000000063b1513 RBX: 0000000000000000 RCX: ffffffff8b5e86f9
RDX: 0000000000000000 RSI: ffffffff8daa3473 RDI: ffffffff8bf1d300
RBP: fffffbfff1c12f50 R08: 0000000000000001 R09: ffffed101708672d
R10: ffff8880b843396b R11: 00000000ffffffff R12: 0000000000000000
R13: ffffffff8e097a80 R14: ffffffff9085ced0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff88812499c000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f04c57a4f98 CR3: 00000000639c1000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3f6/0x4d0 init/main.c:1111
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148