rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10490 ticks this GP) idle=93d/1/0x4000000000000000 softirq=10079/10079 fqs=3 
	(t=10501 jiffies g=13285 q=182)
rcu: rcu_preempt kthread starved for 10478 jiffies! g13285 f0x0 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:28112 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:
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4989 Comm: syz.3.167 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__clear_user+0x22/0x70 arch/x86/lib/usercopy_64.c:45
Code: eb b9 00 00 cc cc 00 00 41 56 53 48 89 f3 49 89 fe e8 a2 b7 6e fd 48 c7 c7 5d 26 bf 8b be 14 00 00 00 e8 41 47 a4 fd 0f 01 cb <89> d8 83 e0 07 48 c1 eb 03 4c 89 f7 48 89 d9 48 85 c9 74 19 66 2e
RSP: 0018:ffffc9000342fb08 EFLAGS: 00040293
RAX: ffffffff81aec616 RBX: 0000000000000040 RCX: ffff88805f711dc0
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000342fcb0 R08: ffff88805f711dc7 R09: 1ffff1100bee23b8
R10: dffffc0000000000 R11: ffffed100bee23b9 R12: 0000000000000007
R13: ffff88805f711dc0 R14: 00007ffc725d91c0 R15: 0000000000000000
FS:  000055557b8c7500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b32c16ff8 CR3: 000000002372b000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 xsave_to_user_sigframe arch/x86/include/asm/fpu/internal.h:346 [inline]
 copy_fpregs_to_sigframe arch/x86/kernel/fpu/signal.c:141 [inline]
 copy_fpstate_to_sigframe+0x464/0xbf0 arch/x86/kernel/fpu/signal.c:203
 get_sigframe arch/x86/kernel/signal.c:295 [inline]
 __setup_rt_frame arch/x86/kernel/signal.c:471 [inline]
 setup_rt_frame arch/x86/kernel/signal.c:780 [inline]
 handle_signal arch/x86/kernel/signal.c:824 [inline]
 arch_do_signal_or_restart+0x679/0x12c0 arch/x86/kernel/signal.c:869
 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
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fd8e5e5c234
Code: 1d 91 db 3a 00 4c 89 c5 eb 1c 66 66 2e 0f 1f 84 00 00 00 00 00 90 48 81 c5 f0 00 00 00 48 39 dd 0f 84 f4 fb ff ff 80 7d 20 00 <74> ea 8b 45 0c 85 c0 74 e3 48 89 ef e8 cb be ff ff eb d9 66 0f 1f
RSP: 002b:00007ffc725d93c0 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007fd8e6209da0 RCX: 0000000000031128
RDX: 000000000001348a RSI: 00007ffc725d94e0 RDI: 00000000330411fc
RBP: 00007fd8e6208360 R08: 00007fd8e6207fa0 R09: 0032671c73c9669a
R10: 000000696ac47c61 R11: 00000000000096a0 R12: 00007ffc725d94e0
R13: 00007fd8e620809c R14: 000000000001e027 R15: 00007ffc725d94c0
 </TASK>
NMI backtrace for cpu 0
CPU: 0 PID: 4988 Comm: syz.4.166 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_dump_cpu_stacks+0x22f/0x380 kernel/rcu/tree_stall.h:349
 print_cpu_stall+0x31d/0x5f0 kernel/rcu/tree_stall.h:633
 check_cpu_stall kernel/rcu/tree_stall.h:727 [inline]
 rcu_pending kernel/rcu/tree.c:3936 [inline]
 rcu_sched_clock_irq+0x6ea/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:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202
Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 1e 4b 97 f7 48 89 df e8 56 23 98 f7 e8 81 18 b9 f7 fb bf 01 00 00 00 <e8> 36 2a 8c f7 65 8b 05 67 26 3c 76 85 c0 74 02 5b c3 e8 b4 33 3a
RSP: 0018:ffffc900030ffbc0 EFLAGS: 00000282
RAX: fb6a2fc79354ec00 RBX: ffff8880581eb780 RCX: fb6a2fc79354ec00
RDX: dffffc0000000000 RSI: ffffffff8a2b3100 RDI: 0000000000000001
RBP: 0000000000000000 R08: ffff8880581eb783 R09: 1ffff1100b03d6f0
R10: dffffc0000000000 R11: ffffed100b03d6f1 R12: ffff8880581eb780
R13: 0000000000000021 R14: dffffc0000000000 R15: 000000001c000004
 spin_unlock_irq include/linux/spinlock.h:414 [inline]
 get_signal+0x11e2/0x12d0 kernel/signal.c:2903
 arch_do_signal_or_restart+0xe7/0x12c0 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
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f972f096e57
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:00007f972d2f00e8 EFLAGS: 00000246
RAX: 00000000000000ca RBX: 00007f972f30ffa8 RCX: 00007f972f096e59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f972f30ffa8
RBP: 00007f972f30ffa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f972f310038 R14: 00007ffe74e73b30 R15: 00007ffe74e73c18
 </TASK>