rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (0 ticks this GP) idle=fb24/1/0x4000000000000000 softirq=140527/140527 fqs=0
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P28906/1:b..l
rcu: (detected by 0, t=10502 jiffies, g=171833, q=454 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 28954 Comm: syz.1.5629 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__rdmsr arch/x86/include/asm/msr.h:75 [inline]
RIP: 0010:native_read_msr arch/x86/include/asm/msr.h:108 [inline]
RIP: 0010:get_debugctlmsr arch/x86/include/asm/debugreg.h:183 [inline]
RIP: 0010:vcpu_enter_guest arch/x86/kvm/x86.c:11455 [inline]
RIP: 0010:vcpu_run+0x2b20/0x5ca0 arch/x86/kvm/x86.c:11765
Code: 1d 45 a2 7e 12 31 ff 81 e3 aa 00 00 00 48 89 de e8 b5 86 7c 00 48 85 db 0f 85 27 15 00 00 e8 c7 8b 7c 00 b9 d9 01 00 00 0f 32 <48> c1 e2 20 48 09 c2 48 89 d3 0f 1f 44 00 00 e8 ac 8b 7c 00 49 8d
RSP: 0018:ffffc90005e6fa80 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 00000000000001d9
RDX: 0000000000000000 RSI: ffffffff818c0359 RDI: ffff88803c5b4a00
RBP: ffffc90005e6fc00 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff88804ebd8038
R13: ffff88804ebd8300 R14: dffffc0000000000 R15: ffff88804ebd8000
FS: 00007fba96edc6c0(0000) GS:ffff888124479000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 00000000600c0000 CR4: 00000000003526f0
Call Trace:
kvm_arch_vcpu_ioctl_run+0x5b6/0x1890 arch/x86/kvm/x86.c:12120
kvm_vcpu_ioctl+0x730/0x1720 virt/kvm/kvm_main.c:4469
vfs_ioctl fs/ioctl.c:51 [inline]
__do_sys_ioctl fs/ioctl.c:597 [inline]
__se_sys_ioctl fs/ioctl.c:583 [inline]
__x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba95f9cdd9
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fba96edc028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007fba96215fa0 RCX: 00007fba95f9cdd9
RDX: 0000000000000000 RSI: 000000000000ae80 RDI: 000000000000000b
RBP: 00007fba96032d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fba96216038 R14: 00007fba96215fa0 R15: 00007ffc78f75a08
task:syz.0.5618 state:R running task stack:25880 pid:28906 tgid:28905 ppid:17518 task_flags:0x40044c flags:0x00080001
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7512
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:476 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
irqentry_exit+0x1fe/0x790 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872
Code: 05 fb fd 25 12 83 f8 07 0f 87 d9 02 00 00 48 0f a3 05 06 15 f3 0e 0f 82 a4 02 00 00 8b 35 8e 48 f3 0e 85 f6 0f 85 bf 00 00 00 <48> 8b 44 24 30 65 48 2b 05 9d fd 25 12 0f 85 ed 02 00 00 48 83 c4
RSP: 0018:ffffc900071e6d48 EFLAGS: 00000206
RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: ffffffff8def8e2a RDI: ffffffff8c1c3200
RBP: ffffffff8e7e54e0 R08: 00000000dacd92cc R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
rcu_read_lock include/linux/rcupdate.h:838 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
save_stack+0x162/0x1e0 mm/page_owner.c:165
__reset_page_owner+0x84/0x190 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1402 [inline]
free_unref_folios+0xa0d/0x16f0 mm/page_alloc.c:3004
folios_put_refs+0x571/0xa90 mm/swap.c:1008
free_pages_and_swap_cache+0x22d/0x3b0 mm/swap_state.c:401
__tlb_batch_free_encoded_pages+0xe9/0x280 mm/mmu_gather.c:138
tlb_batch_pages_flush mm/mmu_gather.c:151 [inline]
tlb_flush_mmu_free mm/mmu_gather.c:417 [inline]
tlb_flush_mmu+0xe9/0x590 mm/mmu_gather.c:424
zap_pte_range mm/memory.c:1957 [inline]
zap_pmd_range mm/memory.c:2004 [inline]
zap_pud_range mm/memory.c:2032 [inline]
zap_p4d_range mm/memory.c:2053 [inline]
__zap_vma_range+0x230e/0x4bf0 mm/memory.c:2093
unmap_vmas+0x299/0x5f0 mm/memory.c:2162
exit_mmap+0x1ef/0xa10 mm/mmap.c:1300
__mmput+0x12a/0x410 kernel/fork.c:1178
mmput+0x67/0x80 kernel/fork.c:1201
exit_mm kernel/exit.c:581 [inline]
do_exit+0x833/0x2a60 kernel/exit.c:963
do_group_exit+0xd5/0x2a0 kernel/exit.c:1117
get_signal+0x1ec7/0x21e0 kernel/signal.c:3037
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:238 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fba6c99cdd9
RSP: 002b:00007fba6d91e028 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: 0000000000010106 RBX: 00007fba6cc15fa0 RCX: 00007fba6c99cdd9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000007
RBP: 00007fba6ca32d69 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fba6cc16038 R14: 00007fba6cc15fa0 R15: 00007ffcd73b5db8
rcu: rcu_preempt kthread starved for 10502 jiffies! g171833 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:28904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5387 [inline]
__schedule+0x10e9/0x6820 kernel/sched/core.c:7188
__schedule_loop kernel/sched/core.c:7267 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7282
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:63
Code: 86 93 02 e9 c3 42 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 a3 e0 21 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:ffffffff8e407e00 EFLAGS: 00000242
RAX: 0000000008d89e51 RBX: ffffffff8e4955c0 RCX: ffffffff8b89b045
RDX: 0000000000000000 RSI: ffffffff8df1e362 RDI: ffffffff8c1c3200
RBP: 0000000000000000 R08: 0000000000000001 R09: ffffed10170867b5
R10: ffff8880b8433dab R11: 0000000000000000 R12: 0000000000000000
R13: fffffbfff1c92ab8 R14: 0000000000000000 R15: ffffffff90d78750
FS: 0000000000000000(0000) GS:ffff888124379000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8980f456b8 CR3: 000000002e1cf000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline]
default_idle+0x9/0x10 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:199 [inline]
do_idle+0x464/0x590 kernel/sched/idle.c:352
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:451
rest_init+0x251/0x260 init/main.c:762
start_kernel+0x484/0x490 init/main.c:1220
x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x12b/0x130 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148