rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (9 ticks this GP) idle=7b04/1/0x4000000000000000 softirq=14143/14143 fqs=17
rcu: 	(detected by 0, t=10502 jiffies, g=13845, q=633 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 5943 Comm: syz.2.57 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:separate_irq_context kernel/locking/lockdep.c:4703 [inline]
RIP: 0010:__lock_acquire+0x737/0x2cf0 kernel/locking/lockdep.c:5221
Code: 00 4d 85 ff 0f 84 8e 00 00 00 41 83 ff 31 0f 83 ca 23 00 00 4b 8d 04 bf 4d 89 ec 41 8b 6d 20 48 8b 4c 24 20 8b 44 c1 f8 31 e8 <25> 00 60 00 00 0f 95 c1 89 0c 24 31 c9 f7 d8 48 19 c9 48 09 cb 48
RSP: 0000:ffffc90000a08be0 EFLAGS: 00000002
RAX: 0000000000084a46 RBX: 2710a232809217a9 RCX: ffff88807ebae7d0
RDX: 0000000000000008 RSI: ffff88807ebae820 RDI: ffff88807ebadc40
RBP: 00000000000c4074 R08: ffffffff81b2765a R09: ffff8880b8728298
R10: dffffc0000000000 R11: fffffbfff20614ff R12: ffff88807ebae820
R13: ffff88807ebae820 R14: ffff88807ebadc40 R15: 0000000000000002
FS:  0000000000000000(0000) GS:ffff888125390000(0063) knlGS:00000000f5475b40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 000000008000d000 CR3: 000000007b0c0000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
 __raw_spin_lock_irq include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock_irq+0x3d/0x50 kernel/locking/spinlock.c:174
 __run_hrtimer kernel/time/hrtimer.c:1934 [inline]
 __hrtimer_run_queues+0x46a/0xa20 kernel/time/hrtimer.c:1994
 hrtimer_interrupt+0x44b/0x950 kernel/time/hrtimer.c:2113
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1067
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198
Code: f7 e8 0d 65 f7 f5 f7 c3 00 02 00 00 74 05 e8 60 f8 22 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 54 e7 e8 f5 65 8b 05 ed 20 8e 07 85 c0 74 18 5b 41 5e e9 51 48
RSP: 0000:ffffc9000d586ec8 EFLAGS: 00000206
RAX: 0000000000000002 RBX: 0000000000000282 RCX: 0000000080000202
RDX: 0000000000000002 RSI: ffffffff8dfa5add RDI: 0000000000000001
RBP: ffffc9000d5871b0 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: ffff888020f74290
R13: dffffc0000000000 R14: ffff888020f742a8 R15: ffff888020f742f8
 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline]
 taprio_change+0x30fe/0x3e50 net/sched/sch_taprio.c:1986
 taprio_init+0x96f/0xbe0 net/sched/sch_taprio.c:2125
 qdisc_create+0x7c4/0xf20 net/sched/sch_api.c:1319
 __tc_modify_qdisc net/sched/sch_api.c:1753 [inline]
 tc_modify_qdisc+0x16f0/0x2290 net/sched/sch_api.c:1817
 rtnetlink_rcv_msg+0x77e/0xbe0 net/core/rtnetlink.c:7004
 netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
 netlink_unicast+0x75c/0x8e0 net/netlink/af_netlink.c:1344
 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:787 [inline]
 __sock_sendmsg net/socket.c:802 [inline]
 ____sys_sendmsg+0x972/0x9f0 net/socket.c:2698
 ___sys_sendmsg+0x2a5/0x360 net/socket.c:2752
 __sys_sendmsg+0x183/0x260 net/socket.c:2784
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x229/0x6e0 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7fd501c
Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8
RSP: 002b:00000000f547550c EFLAGS: 00000206 ORIG_RAX: 0000000000000172
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 00000000800012c0
RDX: 0000000000000010 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 10468 jiffies! g13845 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:26880 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5387 [inline]
 __schedule+0x17b4/0x5680 kernel/sched/core.c:7188
 __schedule_loop kernel/sched/core.c:7267 [inline]
 schedule+0x164/0x360 kernel/sched/core.c:7282
 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 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:
CPU: 0 UID: 0 PID: 5938 Comm: syz.3.56 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:variable_ffs arch/x86/include/asm/bitops.h:312 [inline]
RIP: 0010:handle_softirqs+0x160/0x840 kernel/softirq.c:610
Code: 89 6c 24 20 0f b7 db 48 c7 c7 20 1d cb 8b e8 d7 81 20 0a 65 66 c7 05 a5 30 b1 11 00 00 e8 e8 07 46 00 fb 48 c7 c5 c0 a0 60 8e <b8> ff ff ff ff 0f bc c3 41 89 c6 41 ff c6 0f 84 09 04 00 00 89 5c
RSP: 0000:ffffc90000007f28 EFLAGS: 00000202
RAX: 00000000007d0c2c RBX: 0000000000000100 RCX: 0000000000000102
RDX: 0000000000000002 RSI: ffffffff8dfa5add RDI: ffffffff8c28ac60
RBP: ffffffff8e60a0c0 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: 0000000000000000
R13: 0000000000000000 R14: ffff8880337c8000 R15: dffffc0000000000
FS:  0000000000000000(0000) GS:ffff888125290000(0063) knlGS:00000000f53fdb40
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: 00000000f72577d0 CR3: 000000002975e000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 __do_softirq kernel/softirq.c:656 [inline]
 invoke_softirq kernel/softirq.c:496 [inline]
 __irq_exit_rcu+0xca/0x220 kernel/softirq.c:735
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1061
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfdf/0x13d0 kernel/smp.c:892
Code: 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 25 01 0c 00 eb 37 f3 90 43 0f b6 04 2c 84 c0 75 10 41 f7 06 01 00 00 00 <74> 1e e8 0a 01 0c 00 eb e5 44 89 f1 80 e1 07 80 c1 03 38 c1 7c e3
RSP: 0000:ffffc9000553f200 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffff8880b863c148 RCX: 0000000000080000
RDX: ffffc90005ff2000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000553f340 R08: ffffffff9030a7f7 R09: 1ffffffff20614fe
R10: dffffc0000000000 R11: fffffbfff20614ff R12: 1ffff110170e8169
R13: dffffc0000000000 R14: ffff8880b8740b48 R15: 0000000000000001
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1057
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:46 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x5c3/0x10b0 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:509 [inline]
 tlb_flush_mmu+0x1af/0xa30 mm/mmu_gather.c:423
 tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:549
 unmap_region+0x2a5/0x330 mm/vma.c:491
 vms_clear_ptes mm/vma.c:1303 [inline]
 vms_clean_up_area mm/vma.c:1315 [inline]
 __mmap_setup mm/vma.c:2476 [inline]
 __mmap_region mm/vma.c:2753 [inline]
 mmap_region+0xc9a/0x22a0 mm/vma.c:2857
 do_mmap+0xc39/0x10c0 mm/mmap.c:560
 vm_mmap_pgoff+0x2c9/0x4f0 mm/util.c:581
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x229/0x6e0 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x33/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf700f01c
Code: 90 85 d2 74 0a 89 ce 81 e6 ff 0f 00 00 89 32 85 c0 74 05 c1 e9 0c 89 08 31 c0 5e 5d c3 90 0f 1f 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 58 b8
RSP: 002b:00000000f53fd50c EFLAGS: 00000206 ORIG_RAX: 00000000000000c0
RAX: ffffffffffffffda RBX: 0000000080000000 RCX: 0000000000fbe000
RDX: 000000000080000a RSI: 0000000000000031 RDI: 00000000ffffffff
RBP: 00000000d0fb8000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>