rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 1-...!: (10503 ticks this GP) idle=2ad/1/0x4000000000000000 softirq=5595/5598 fqs=2
(t=10500 jiffies g=5797 q=54)
rcu: rcu_preempt kthread starved for 10493 jiffies! g5797 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:28192 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5030 [inline]
__schedule+0x11b8/0x43b0 kernel/sched/core.c:6376
schedule+0x11b/0x1e0 kernel/sched/core.c:6459
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
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: 4326 Comm: syz.0.1 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:344 [inline]
RIP: 0010:cpu_online include/linux/cpumask.h:895 [inline]
RIP: 0010:trace_user_exit+0x2f/0x190 include/trace/events/context_tracking.h:48
Code: 12 dc ff 0f 1f 44 00 00 e8 1e 12 dc ff 65 8b 1d 4f 63 66 7e bf 07 00 00 00 89 de e8 6b 15 dc ff 83 fb 07 77 55 e8 01 12 dc ff <41> 89 de c1 eb 06 48 8d 3c dd a8 6e 69 8d be 08 00 00 00 e8 b9 76
RSP: 0018:ffffc9000382fee0 EFLAGS: 00000046
RAX: ffffffff819bb21f RBX: 0000000000000000 RCX: 0000000000080000
RDX: ffffc9000d631000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000382ff48 R08: dffffc0000000000 R09: fffffbfff1ad2dd6
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc9000382ff58 R15: 0000000000000000
FS: 00007f8afc0306c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 0000000025085000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
__context_tracking_exit+0x51/0x80 kernel/context_tracking.c:161
user_exit_irqoff include/linux/context_tracking.h:47 [inline]
__enter_from_user_mode kernel/entry/common.c:22 [inline]
syscall_enter_from_user_mode+0x56/0x70 kernel/entry/common.c:110
do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8afdde0ba7
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d f2 6c d6 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 13 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007f8afc02f048 EFLAGS: 00000206 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007f8afc02f1b0 RCX: 00007f8afdde0ba7
RDX: 00007f8afc02f080 RSI: 00007f8afc02f1b0 RDI: 0000000000000021
RBP: 0000000000000000 R08: 00000000000003ff R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: cccccccccccccccd
R13: 00007f8afe011128 R14: 00007f8afe011090 R15: 00007fff74828638
NMI backtrace for cpu 1
CPU: 1 PID: 4327 Comm: syz.0.1 Not tainted 5.15.189-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
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_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+0x6d8/0x1110 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+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:__syscall_enter_from_user_work kernel/entry/common.c:93 [inline]
RIP: 0010:syscall_enter_from_user_mode+0x2a/0x70 kernel/entry/common.c:114
Code: 41 56 53 48 89 f3 49 89 fe 48 8b 7c 24 10 e8 3d f6 ff ff eb 31 eb 35 e8 84 ab d5 f7 e8 7f a9 d5 f7 fb 65 48 8b 05 06 37 5a 76 <48> 8b 70 08 40 f6 c6 3f 74 0b 4c 89 f7 5b 41 5e e9 f1 ee bd f7 48
RSP: 0018:ffffc9000383ff08 EFLAGS: 00000286
RAX: ffff8880232dbb80 RBX: 0000000000000027 RCX: 423be7e9eb8f4000
RDX: dffffc0000000000 RSI: ffffffff8a0b15c0 RDI: ffffffff8a599340
RBP: ffffc9000383ff48 R08: dffffc0000000000 R09: fffffbfff1ad2dd6
R10: fffffbfff1ad2dd6 R11: 1ffffffff1ad2dd5 R12: 0000000000000000
R13: 0000000000000000 R14: ffffc9000383ff58 R15: 0000000000000000
do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:76
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f8afdde0ba7
Code: 0b e9 68 fe ff ff 48 83 c4 18 48 8d 3d f2 6c d6 00 5b 5d 41 5c 41 5d 41 5e 41 5f e9 13 f8 fb ff 0f 1f 00 b8 27 00 00 00 0f 05 0f 1f 84 00 00 00 00 00 b8 6e 00 00 00 0f 05 c3 0f 1f 84 00 00
RSP: 002b:00007f8afc00e548 EFLAGS: 00000206 ORIG_RAX: 0000000000000027
RAX: ffffffffffffffda RBX: 00007f8afc00e6b0 RCX: 00007f8afdde0ba7
RDX: 00007f8afc00e580 RSI: 00007f8afc00e6b0 RDI: 0000000000000021
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007f8afe011218 R14: 00007fff74828550 R15: 00007fff74828638