rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 0-...!: (1 GPs behind) idle=2ed/1/0x4000000000000000 softirq=13016/13017 fqs=12
(t=10500 jiffies g=17053 q=88)
rcu: rcu_preempt kthread starved for 10466 jiffies! g17053 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:27408 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11c3/0x4350 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/0x11f0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x9a/0x370 kernel/rcu/tree.c:2145
kthread+0x42e/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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 7104 Comm: syz.3.885 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline]
RIP: 0010:__pv_queued_spin_lock_slowpath+0x520/0x9b0 kernel/locking/qspinlock.c:508
Code: 8b 44 24 18 c6 00 00 48 8b 44 24 10 42 0f b6 04 28 84 c0 0f 85 1c 01 00 00 48 8d 43 01 c6 00 01 41 bc 00 80 ff ff eb 07 f3 90 <41> ff c4 74 47 43 0f b6 04 2e 84 c0 75 2b 80 3b 00 75 eb 48 89 df
RSP: 0018:ffffc9000261f8c0 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffffc90000e06508 RCX: 834eb7bbd1c35d00
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4b80
RBP: ffffc9000261f9b8 R08: ffffffff902141af R09: 1ffffffff2042835
R10: dffffc0000000000 R11: fffffbfff2042836 R12: 00000000ffff8e4c
R13: dffffc0000000000 R14: 1ffff920001c0ca1 R15: ffff8880b9130001
FS: 000055558a801500(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f6e4b0d0a08 CR3: 00000000458b5000 CR4: 00000000003506e0
DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600
Call Trace:
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+0x265/0x2f0 kernel/locking/spinlock_debug.c:115
spin_lock include/linux/spinlock.h:364 [inline]
unqueue_me kernel/futex/core.c:2551 [inline]
futex_wait+0x26f/0x680 kernel/futex/core.c:2971
do_futex+0xdc2/0x12b0 kernel/futex/core.c:4018
__do_sys_futex kernel/futex/core.c:4095 [inline]
__se_sys_futex+0x389/0x420 kernel/futex/core.c:4076
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: 0033:0x7f240bc28159
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:00007ffe0eb6e898 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00000000000252cb RCX: 00007f240bc28159
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f240beaffac
RBP: 0000000000000032 R08: 000f050000cb3402 R09: 0000000000000000
R10: 00007ffe0eb6e9a0 R11: 0000000000000246 R12: 00007ffe0eb6e9c0
R13: 00007f240beaffac R14: 00000000000252fd R15: 00007ffe0eb6e9a0
NMI backtrace for cpu 0
CPU: 0 PID: 7105 Comm: syz.3.885 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026
Call Trace:
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+0x22d/0x380 kernel/rcu/tree_stall.h:349
print_cpu_stall+0x31f/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+0x6ec/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+0x4b0/0xb60 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x397/0x8b0 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+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:should_resched arch/x86/include/asm/preempt.h:103 [inline]
RIP: 0010:__local_bh_enable_ip+0x13e/0x1c0 kernel/softirq.c:408
Code: 8a e8 16 f1 78 08 65 66 8b 05 ae 61 ba 7e 66 85 c0 75 54 bf 01 00 00 00 e8 df 21 09 00 e8 ca 17 36 00 fb 65 8b 05 5a 38 b9 7e <85> c0 75 05 e8 99 45 b7 ff 48 c7 04 24 0e 36 e0 45 4b c7 04 37 00
RSP: 0018:ffffc90000007a00 EFLAGS: 00000286
RAX: 0000000000000102 RBX: 0000000000000200 RCX: 800c99a55d204e00
RDX: dffffc0000000000 RSI: ffffffff8a2b2be0 RDI: ffffffff8a7a4b80
RBP: ffffc90000007a88 R08: ffffffff902141d7 R09: 1ffffffff204283a
R10: dffffc0000000000 R11: fffffbfff204283b R12: ffffffff88805485
R13: ffff88807959c588 R14: dffffc0000000000 R15: 1ffff92000000f40
__rhashtable_remove_fast_one include/linux/rhashtable.h:1048 [inline]
__rhashtable_remove_fast include/linux/rhashtable.h:1083 [inline]
rhashtable_remove_fast include/linux/rhashtable.h:1112 [inline]
inet_frag_kill+0x9c6/0xe80 net/ipv4/inet_fragment.c:244
ipq_kill net/ipv4/ip_fragment.c:118 [inline]
ip_expire+0x161/0x6c0 net/ipv4/ip_fragment.c:156
call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
expire_timers kernel/time/timer.c:1699 [inline]
__run_timers+0x56c/0x810 kernel/time/timer.c:1970
run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
handle_softirqs+0x336/0x830 kernel/softirq.c:576
__do_softirq kernel/softirq.c:610 [inline]
invoke_softirq kernel/softirq.c:450 [inline]
__irq_exit_rcu+0x13b/0x230 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
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:futex_wake+0x270/0x540 kernel/futex/core.c:1684
Code: 00 48 89 5c 24 10 eb 16 e8 dd 45 0c 00 49 39 dc 0f 84 22 02 00 00 e8 cf 45 0c 00 4d 89 e6 4c 89 f0 48 c1 e8 03 42 80 3c 28 00 <74> 08 4c 89 f7 e8 c6 8a 51 00 4d 8b 26 4d 89 f7 49 83 c7 20 74 c8
RSP: 0018:ffffc9000337fb80 EFLAGS: 00000246
RAX: 1ffff920004c3f75 RBX: ffffc90000e06548 RCX: 0000000000000001
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc9000337fb00
RBP: ffffc9000337fc70 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff5200066ff60 R12: 0000000000000001
R13: dffffc0000000000 R14: ffffc9000261fba8 R15: 00007f240beaffac
do_futex+0xd83/0x12b0 kernel/futex/core.c:4023
__do_sys_futex kernel/futex/core.c:4095 [inline]
__se_sys_futex+0x389/0x420 kernel/futex/core.c:4076
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: 0033:0x7f240bc28159
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:00007f2409e800e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: ffffffffffffffda RBX: 00007f240beaffa8 RCX: 00007f240bc28159
RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f240beaffac
RBP: 00007f240beaffa0 R08: 000f9d9680fa97c8 R09: 0000000000000000
R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000
R13: 00007f240beb0038 R14: 00007ffe0eb6e650 R15: 00007ffe0eb6e738