rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (10500 ticks this GP) idle=d67c/1/0x4000000000000000 softirq=113621/113621 fqs=798
rcu: 	(t=10502 jiffies g=114837 q=4307 ncpus=2)
rcu: rcu_preempt kthread starved for 8893 jiffies! g114837 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:27288 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </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 UID: 0 PID: 0 Comm: swapper/1 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:pie_calculate_probability+0x6b0/0x7e0 net/sched/sch_pie.c:423
Code: 85 bb 00 00 00 41 0f b6 5d 00 31 ff 89 de e8 57 8e 5b f8 85 db 74 07 e8 4e 8b 5b f8 eb 1f e8 47 8b 5b f8 48 89 e8 48 c1 e8 03 <42> 80 3c 20 00 74 08 48 89 ef e8 a1 2a c1 f8 4c 89 7d 00 48 83 c4
RSP: 0018:ffffc90000a08a90 EFLAGS: 00000a02
RAX: 1ffff92003ddc6b3 RBX: 0000000000000000 RCX: ffff88801c2e5ac0
RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000
RBP: ffffc9001eee3598 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141154 R12: dffffc0000000000
R13: ffff8880216d3b1a R14: 1ffff110042da763 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff888125e12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f65e95e6038 CR3: 0000000075670000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 fq_pie_timer+0x288/0x5b0 net/sched/sch_fq_pie.c:402
 call_timer_fn+0x17e/0x5f0 kernel/time/timer.c:1747
 expire_timers kernel/time/timer.c:1798 [inline]
 __run_timers kernel/time/timer.c:2372 [inline]
 __run_timer_base+0x61a/0x860 kernel/time/timer.c:2384
 run_timer_base kernel/time/timer.c:2393 [inline]
 run_timer_softirq+0xb7/0x180 kernel/time/timer.c:2403
 handle_softirqs+0x283/0x870 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:723
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82
Code: c3 e6 02 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d e3 f0 1c 00 f3 0f 1e fa fb f4 <e9> 98 e6 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6
RAX: 6a455462efa69900 RBX: ffffffff81960c17 RCX: 6a455462efa69900
RDX: 0000000000000001 RSI: ffffffff8d7e865f RDI: ffffffff8bc074e0
RBP: ffffc90000197f10 R08: ffff8880b8732fdb R09: 1ffff110170e65fb
R10: dffffc0000000000 R11: ffffed10170e65fc R12: ffffffff8f9e0f70
R13: 0000000000000001 R14: 0000000000000001 R15: 1ffff1100385cb58
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:767
 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x1e7/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:428
 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:315
 common_startup_64+0x13e/0x147
 </TASK>
CPU: 0 UID: 0 PID: 17500 Comm: syz.2.2964 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
RIP: 0010:lock_is_held_type+0x137/0x190 kernel/locking/lockdep.c:5945
Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 d9 99 45 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9001157ef60 EFLAGS: 00000206
RAX: dfe4b639909c5600 RBX: 0000000000000001 RCX: dfe4b639909c5600
RDX: ffff88802ffbdac0 RSI: ffffffff8d9d14a1 RDI: ffffffff8bc074e0
RBP: 00000000ffffffff R08: ffff88802ffbdac0 R09: 0000000000000002
R10: 00000000ffffffff R11: 0000000000000002 R12: 0000000000000246
R13: ffff88802ffbdac0 R14: ffffffff8e13d320 R15: 0000000000000002
FS:  00007f8566a346c0(0000) GS:ffff888125d12000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055557dcf2808 CR3: 0000000080516000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000083
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 qdisc_lookup_rcu+0x381/0x6d0 net/sched/sch_api.c:333
 qdisc_tree_reduce_backlog+0x1b2/0x480 net/sched/sch_api.c:795
 sfq_change net/sched/sch_sfq.c:740 [inline]
 sfq_init+0x1a19/0x2540 net/sched/sch_sfq.c:804
 qdisc_create+0x7a9/0xea0 net/sched/sch_api.c:1319
 __tc_modify_qdisc net/sched/sch_api.c:1748 [inline]
 tc_modify_qdisc+0x1538/0x20e0 net/sched/sch_api.c:1812
 rtnetlink_rcv_msg+0x77c/0xb70 net/core/rtnetlink.c:6963
 netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2552
 netlink_unicast_kernel net/netlink/af_netlink.c:1320 [inline]
 netlink_unicast+0x82c/0x9e0 net/netlink/af_netlink.c:1346
 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1896
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg+0x21c/0x270 net/socket.c:742
 ____sys_sendmsg+0x52d/0x830 net/socket.c:2630
 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2684
 __sys_sendmmsg+0x227/0x430 net/socket.c:2773
 __do_sys_sendmmsg net/socket.c:2800 [inline]
 __se_sys_sendmmsg net/socket.c:2797 [inline]
 __x64_sys_sendmmsg+0xa0/0xc0 net/socket.c:2797
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f8565b8eec9
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f8566a34038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133
RAX: ffffffffffffffda RBX: 00007f8565de5fa0 RCX: 00007f8565b8eec9
RDX: 040000000000009f RSI: 00002000000002c0 RDI: 0000000000000004
RBP: 00007f8565c11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f8565de6038 R14: 00007f8565de5fa0 R15: 00007f8565f0fa28
 </TASK>