rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=19329, q=349)
rcu: All QSes seen, last rcu_preempt kthread activity 10494 (4294979271-4294968777), jiffies_till_next_fqs=1, root ->qsmask 0x0
rcu: rcu_preempt kthread starved for 10494 jiffies! g19329 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R  running task     stack:27728 pid:   15 ppid:     2 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5049 [inline]
 __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395
 schedule+0x11b/0x1e0 kernel/sched/core.c:6478
 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117
 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972
 rcu_gp_kthread+0x9b/0x370 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: 6794 Comm: syz.0.651 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 nmi_cpu_backtrace+0x3a2/0x3d0 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+0x1110/0x1270 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+0x843/0x1120 kernel/rcu/tree.c:2619
 update_process_times+0x193/0x200 kernel/time/timer.c:2021
 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:1685 [inline]
 __hrtimer_run_queues+0x4b4/0xb70 kernel/time/hrtimer.c:1749
 hrtimer_interrupt+0x3bb/0x8d0 kernel/time/hrtimer.c:1811
 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+0x9b/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:__kasan_check_read+0x0/0x10 mm/kasan/shadow.c:31
Code: 41 5c 41 5d 41 5e 41 5f 5d c3 48 c7 c7 2f 14 df 8b eb 0a 48 c7 c7 b5 37 c5 8b 48 89 de e8 f8 6d f4 07 31 ed eb d7 00 00 cc cc <89> f6 48 8b 0c 24 31 d2 e9 43 ef ff ff 0f 1f 00 89 f6 48 8b 0c 24
RSP: 0018:ffffc9000336f9d8 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000001
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff8d8a06e8
RBP: ffffc9000336faf8 R08: 0000000000000001 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff5200066df90 R12: ffff888016c68828
R13: 1ffff9200066df48 R14: 0000000000000001 R15: dffffc0000000000
 instrument_atomic_read include/linux/instrumented.h:71 [inline]
 test_bit include/asm-generic/bitops/instrumented-non-atomic.h:134 [inline]
 cpumask_test_cpu include/linux/cpumask.h:344 [inline]
 cpu_online include/linux/cpumask.h:895 [inline]
 trace_lock_acquire include/trace/events/lock.h:13 [inline]
 lock_acquire+0xb6/0x400 kernel/locking/lockdep.c:5594
 __might_fault+0xb3/0x110 mm/memory.c:5357
 __copy_from_user include/linux/uaccess.h:109 [inline]
 check_xstate_in_sigframe arch/x86/kernel/fpu/signal.c:33 [inline]
 __fpu_restore_sig arch/x86/kernel/fpu/signal.c:317 [inline]
 fpu__restore_sig+0x24f/0x1060 arch/x86/kernel/fpu/signal.c:466
 restore_sigcontext arch/x86/kernel/signal.c:139 [inline]
 __ia32_sys_rt_sigreturn+0x5e4/0x760 arch/x86/kernel/signal.c:674
 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: 0033:0x7f09f5368e57
Code: 83 c8 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
RSP: 002b:00007f09f35c2028 EFLAGS: 00000246
RAX: 0000000000000049 RBX: 00007f09f55e1fa0 RCX: 00007f09f5368e59
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000004
RBP: 00007f09f53fed6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f09f55e2038 R14: 00007f09f55e1fa0 R15: 00007ffc030aeb98
 </TASK>