rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10500 ticks this GP) idle=0b6c/1/0x4000000000000000 softirq=11254/11254 fqs=4
(t=10502 jiffies g=11757 q=185 ncpus=2)
rcu: rcu_preempt kthread starved for 10494 jiffies! g11757 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:27760 pid:16 ppid:2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5245 [inline]
__schedule+0x11d1/0x40e0 kernel/sched/core.c:6562
schedule+0xb9/0x180 kernel/sched/core.c:6638
schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168
rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706
rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905
kthread+0x29d/0x330 kernel/kthread.c:376
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
rcu: Stack dump where RCU GP kthread last ran:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 PID: 4513 Comm: syz.4.21 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pvclock_read_retry arch/x86/include/asm/pvclock.h:35 [inline]
RIP: 0010:pvclock_clocksource_read+0x1f5/0x760 arch/x86/kernel/pvclock.c:78
Code: 4c 8b 74 24 28 0f 85 bf 02 00 00 49 8b 2a 48 8b 44 24 58 42 0f b6 04 20 84 c0 0f 85 06 03 00 00 44 0f b6 7f 1d 42 0f b6 04 22 <84> c0 0f 85 4f 03 00 00 43 0f b6 04 26 84 c0 0f 85 a3 03 00 00 83
RSP: 0018:ffffc90000007d60 EFLAGS: 00000046
RAX: 0000000000000000 RBX: 0000000000000006 RCX: 0000000000000001
RDX: 1ffffffff1f41000 RSI: ffffffff8fa0801c RDI: ffffffff8fa08000
RBP: 0000000026c4fc3a R08: ffffffff8fa08008 R09: ffffffff8fa08018
R10: ffffffff8fa08010 R11: ffffffff8fa08003 R12: dffffc0000000000
R13: 00000031a6e1bf64 R14: 1ffffffff1f41000 R15: 0000000000000001
FS: 000055556e3ea500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 000000007d7f8000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
kvm_clock_read arch/x86/kernel/kvmclock.c:79 [inline]
kvm_sched_clock_read+0x14/0x40 arch/x86/kernel/kvmclock.c:91
sched_clock_cpu+0x6e/0x260 kernel/sched/clock.c:369
irqtime_account_irq+0x6a/0x1b0 kernel/sched/cputime.c:60
account_hardirq_exit include/linux/vtime.h:159 [inline]
__irq_exit_rcu+0x99/0x230 kernel/softirq.c:676
irq_exit_rcu+0x5/0x20 kernel/softirq.c:691
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline]
sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1118
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [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 ae 54 2e f7 48 89 df e8 f6 1c 2f f7 e8 71 6d 52 f7 fb bf 01 00 00 00 96 7d 22 f7 65 8b 05 57 01 cc 75 85 c0 74 02 5b c3 e8 a4 15 ca
RSP: 0018:ffffc900036f7b98 EFLAGS: 00000282
RAX: bf7be54d7b71f400 RBX: ffff88805b41dc80 RCX: bf7be54d7b71f400
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000001
RBP: ffff88805b41e118 R08: ffff88805b41dc83 R09: 1ffff1100b683b90
R10: dffffc0000000000 R11: ffffed100b683b91 R12: 1ffff1100b683c23
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7efde979acb9
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:00007ffc7eb28b08 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007efde9a15fa0 RCX: 00007efde979acb9
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007efde9808bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efde9a15fac R14: 00007efde9a15fa0 R15: 00007efde9a15fa0
CPU: 1 PID: 4512 Comm: syz.0.23 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [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 ae 54 2e f7 48 89 df e8 f6 1c 2f f7 e8 71 6d 52 f7 fb bf 01 00 00 00 96 7d 22 f7 65 8b 05 57 01 cc 75 85 c0 74 02 5b c3 e8 a4 15 ca
RSP: 0018:ffffc900036e7b98 EFLAGS: 00000282
RAX: 96630d50a11be900 RBX: ffff88805b41ca00 RCX: 96630d50a11be900
RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000001
RBP: ffff88805b41ce98 R08: ffff88805b41ca03 R09: 1ffff1100b683940
R10: dffffc0000000000 R11: ffffed100b683941 R12: 1ffff1100b6839d3
R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000
FS: 000055558bdef500(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000020000006b000 CR3: 0000000074acf000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
spin_unlock_irq include/linux/spinlock.h:401 [inline]
get_signal+0x1163/0x1350 kernel/signal.c:2874
arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871
exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210
__syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82
entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f6d2759acb9
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:00007ffc6f5c1038 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 00007f6d27815fa0 RCX: 00007f6d2759acb9
RDX: 000020000006b000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007f6d27608bf7 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f6d27815fac R14: 00007f6d27815fa0 R15: 00007f6d27815fa0
sched: RT throttling activated