rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 GPs behind) idle=8d3/1/0x4000000000000002 softirq=123750/123752 fqs=3 
	(detected by 1, t=10502 jiffies, g=162233, q=258)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 6955 Comm: syz.0.11352 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:106 [inline]
RIP: 0010:lock_is_held_type+0x61/0x190 kernel/locking/lockdep.c:5662
Code: 0f 85 f4 00 00 00 65 48 8b 1d bb 7e 59 76 83 bb ec 0a 00 00 00 0f 85 df 00 00 00 41 89 f7 49 89 fe 48 c7 04 24 00 00 00 00 9c <8f> 04 24 4c 8b 2c 24 fa 48 c7 c7 20 26 0b 8a e8 4b 0e 00 00 65 ff
RSP: 0018:ffffc90000006fc8 EFLAGS: 00000046
RAX: 0000000000000000 RBX: ffff88805a910000 RCX: e2b619bbe914d300
RDX: 0000000000000100 RSI: 00000000ffffffff RDI: ffffffff8c11c660
RBP: 00000000ffffffff R08: dffffc0000000000 R09: ffffc90000007180
R10: fffff52000000e37 R11: 1ffff92000000e30 R12: dffffc0000000000
R13: ffffc900000071e6 R14: ffffffff8c11c660 R15: 00000000ffffffff
FS:  00007f2bb74516c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000000cf3d CR3: 000000004dc2d000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000200000000300 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
 <IRQ>
 perf_get_guest_cbs include/linux/perf_event.h:1274 [inline]
 perf_misc_flags+0x56/0x1b0 arch/x86/events/core.c:2961
 perf_prepare_sample+0x132/0x1cb0 kernel/events/core.c:7622
 __perf_event_output kernel/events/core.c:7802 [inline]
 perf_event_output_forward+0x146/0x280 kernel/events/core.c:7822
 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515
 perf_tp_event+0x32c/0xb50 kernel/events/core.c:10047
 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021
 perf_trace_preemptirq_template+0x2be/0x380 include/trace/events/preemptirq.h:14
 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40
 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44
 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713
RIP: 0010:rcu_read_unlock_special+0x84/0x480 kernel/rcu/tree_plugin.h:674
Code: f1 f1 f1 00 f2 f2 f2 4a 89 04 2b 66 42 c7 44 2b 09 f3 f3 42 c6 44 2b 0b f3 65 44 8b 35 ad 13 9e 7e 41 f7 c6 00 00 f0 00 74 45 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 66 42 c7 44 2b
RSP: 0018:ffffc90000007780 EFLAGS: 00000206
RAX: e2b619bbe914d300 RBX: 1ffff92000000ef4 RCX: e2b619bbe914d300
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc90000007860 R08: dffffc0000000000 R09: fffffbfff1ff7832
R10: fffffbfff1ff7832 R11: 1ffffffff1ff7831 R12: ffffffff8c120b00
R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001
 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422
 rcu_read_unlock include/linux/rcupdate.h:771 [inline]
 __ip_queue_xmit+0x1244/0x1c00 net/ipv4/ip_output.c:533
 __tcp_transmit_skb+0x1ced/0x31c0 net/ipv4/tcp_output.c:1404
 tcp_delack_timer_handler+0x32e/0x730 net/ipv4/tcp_timer.c:314
 tcp_delack_timer+0x188/0x2e0 net/ipv4/tcp_timer.c:341
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__sanitizer_cov_trace_pc+0x37/0x60 kernel/kcov.c:209
Code: 8b 15 95 a4 8a 7e 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 34 16 00 00 00 74 2c 8b 91 10 16 00 00 83 fa 02 75 21 <48> 8b 91 18 16 00 00 48 8b 32 48 8d 7e 01 8b 89 14 16 00 00 48 39
RSP: 0018:ffffc900031cef58 EFLAGS: 00000246
RAX: ffffffff83fdf7bc RBX: 00000000ffff0a01 RCX: ffff88805a910000
RDX: 0000000000000002 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc900031cf070 R08: ffff88805a910000 R09: 0000000000000012
R10: 0000000000000012 R11: 0000000000000002 R12: 0000000000000000
R13: ffff0a01ffffff10 R14: ffff888071f9066c R15: ffff0a01ffffff10
 number+0x19c/0xf70 lib/vsprintf.c:480
 vsnprintf+0x10fe/0x1a00 lib/vsprintf.c:2877
 vscnprintf+0x29/0x80 lib/vsprintf.c:2914
 bpf_verifier_vlog+0x33/0x350 kernel/bpf/verifier.c:291
 verbose+0x1dc/0x2a0 kernel/bpf/verifier.c:348
 do_check+0x466e/0xeac0 kernel/bpf/verifier.c:11244
 do_check_common+0xe67/0x16c0 kernel/bpf/verifier.c:13502
 do_check_main kernel/bpf/verifier.c:13565 [inline]
 bpf_check+0x31f3/0xf090 kernel/bpf/verifier.c:14136
 bpf_prog_load+0x1043/0x1550 kernel/bpf/syscall.c:2354
 __sys_bpf+0x4c2/0x670 kernel/bpf/syscall.c:4657
 __do_sys_bpf kernel/bpf/syscall.c:4761 [inline]
 __se_sys_bpf kernel/bpf/syscall.c:4759 [inline]
 __x64_sys_bpf+0x78/0x90 kernel/bpf/syscall.c:4759
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2bb91e9ec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f2bb7451038 EFLAGS: 00000246 ORIG_RAX: 0000000000000141
RAX: ffffffffffffffda RBX: 00007f2bb9440fa0 RCX: 00007f2bb91e9ec9
RDX: 0000000000000048 RSI: 000020000000e000 RDI: 0000000000000005
RBP: 00007f2bb926cf91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2bb9441038 R14: 00007f2bb9440fa0 R15: 00007ffe92260008
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10484 jiffies! g162233 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=68977
rcu: rcu_preempt kthread starved for 10485 jiffies! g162233 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1
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:I stack:27168 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11bb/0x4390 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
 kthread+0x436/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
NMI backtrace for cpu 1
CPU: 1 PID: 6779 Comm: syz.5.11283 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
Call Trace:
 <IRQ>
 dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x397/0x3d0 lib/nmi_backtrace.c:111
 nmi_trigger_cpumask_backtrace+0x163/0x280 lib/nmi_backtrace.c:62
 trigger_single_cpu_backtrace include/linux/nmi.h:166 [inline]
 rcu_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
 print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
 check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:1818
 tick_sched_handle kernel/time/tick-sched.c:254 [inline]
 tick_sched_timer+0x37d/0x560 kernel/time/tick-sched.c:1473
 __run_hrtimer kernel/time/hrtimer.c:1690 [inline]
 __hrtimer_run_queues+0x4fe/0xc40 kernel/time/hrtimer.c:1754
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1816
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1097 [inline]
 __sysvec_apic_timer_interrupt+0x137/0x4a0 arch/x86/kernel/apic/apic.c:1114
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0x4d/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline]
RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline]
RIP: 0010:kvm_wait+0x141/0x190 arch/x86/kernel/kvm.c:918
Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 47 0f b6 1f e8 7f e1 49 00 44 38 e3 75 10 66 90 0f 00 2d e1 65 d4 08 fb f4 <e9> 33 ff ff ff fb e9 2d ff ff ff e8 5f e6 74 08 89 f9 80 e1 07 38
RSP: 0018:ffffc90000dd08c0 EFLAGS: 00000246
RAX: 5387b03bc07aaa00 RBX: 0000000000000003 RCX: 5387b03bc07aaa00
RDX: dffffc0000000000 RSI: ffffffff8a0b1820 RDI: ffffffff8a59a480
RBP: ffffc90000dd0970 R08: dffffc0000000000 R09: fffffbfff1ff7832
R10: fffffbfff1ff7832 R11: 1ffffffff1ff7831 R12: 0000000000000003
R13: ffff8880b913b154 R14: dffffc0000000000 R15: 1ffff920001ba118
 pv_wait arch/x86/include/asm/paravirt.h:597 [inline]
 pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline]
 __pv_queued_spin_lock_slowpath+0x60f/0x9c0 kernel/locking/qspinlock.c:508
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:585 [inline]
 queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51
 queued_spin_lock include/asm-generic/qspinlock.h:85 [inline]
 do_raw_spin_lock+0x217/0x280 kernel/locking/spinlock_debug.c:115
 spin_lock include/linux/spinlock.h:363 [inline]
 tcp_write_timer+0x29/0x280 net/ipv4/tcp_timer.c:673
 call_timer_fn+0x16c/0x530 kernel/time/timer.c:1451
 expire_timers kernel/time/timer.c:1496 [inline]
 __run_timers+0x525/0x7c0 kernel/time/timer.c:1767
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1780
 handle_softirqs+0x328/0x820 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x12f/0x220 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:unwind_next_frame+0xa13/0x1d90 arch/x86/kernel/unwind_orc.c:545
Code: 00 4d 89 3e 48 8b 44 24 40 42 80 3c 28 00 4c 8b 74 24 38 4c 8b 7c 24 70 74 08 4c 89 f7 e8 45 b1 87 00 48 8b 44 24 08 49 89 06 <48> 8b 44 24 68 42 0f b6 04 28 84 c0 4c 8b 74 24 28 0f 85 40 10 00
RSP: 0018:ffffc90002ede468 EFLAGS: 00000246
RAX: ffffc90002ede800 RBX: ffffc90002ede528 RCX: 1ffff920005dbc01
RDX: 1ffffffff1bdd2ed RSI: ffffffff8dee976a RDI: ffffc90002ede7f8
RBP: ffffc90002ede570 R08: 0000000000000001 R09: 0000000000000000
R10: fffff520005dbcb1 R11: 1ffff920005dbcaf R12: 1ffffffff1bdd2ed
R13: dffffc0000000000 R14: ffffc90002ede560 R15: ffffc90002ede55d
 arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
 save_stack+0xf3/0x1e0 mm/page_owner.c:119
 __set_page_owner+0x41/0x2d0 mm/page_owner.c:181
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5487
 alloc_pages_vma+0x393/0x7c0 mm/mempolicy.c:2146
 shmem_alloc_page mm/shmem.c:1586 [inline]
 shmem_alloc_and_acct_page+0x427/0xb70 mm/shmem.c:1611
 shmem_getpage_gfp+0x14f4/0x2d40 mm/shmem.c:1906
 shmem_getpage mm/shmem.c:151 [inline]
 shmem_write_begin+0xcd/0x1a0 mm/shmem.c:2474
 generic_perform_write+0x2aa/0x530 mm/filemap.c:3785
 __generic_file_write_iter+0x25f/0x4e0 mm/filemap.c:3912
 generic_file_write_iter+0xa6/0x1b0 mm/filemap.c:3944
 __kernel_write+0x4f9/0x930 fs/read_write.c:539
 __dump_emit+0x243/0x360 fs/coredump.c:943
 dump_user_range+0x84/0x340 fs/coredump.c:1017
 elf_core_dump+0x2ff7/0x3530 fs/binfmt_elf.c:2285
 do_coredump+0x1419/0x2960 fs/coredump.c:894
 get_signal+0x40a/0x12c0 kernel/signal.c:2886
 arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
 handle_signal_work kernel/entry/common.c:154 [inline]
 exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320
 exc_page_fault+0x88/0x100 arch/x86/mm/fault.c:1504
 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606
RIP: 0033:0x7f6879618ed1
Code: 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f
RSP: 002b:00000000fffffeb0 EFLAGS: 00010217
RAX: 0000000000000000 RBX: 00007f6879870180 RCX: 00007f6879618ec9
RDX: 0000000000000000 RSI: 00000000fffffeb0 RDI: 0000000002000400
RBP: 00007f687969bf91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f6879870218 R14: 00007f6879870180 R15: 00007ffe7f3cebd8
 </TASK>