rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=8754/1/0x4000000000000000 softirq=400413/400414 fqs=326
rcu: (detected by 1, t=10502 jiffies, g=450113, q=262 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 27374 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__remove_hrtimer kernel/time/hrtimer.c:1115 [inline]
RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1757 [inline]
RIP: 0010:__hrtimer_run_queues+0x3a7/0xc30 kernel/time/hrtimer.c:1841
Code: b6 04 28 84 c0 0f 85 07 05 00 00 44 8b 2a bf 20 00 00 00 44 89 ee e8 88 9a 12 00 49 83 fd 1f 0f 87 11 05 00 00 e8 39 96 12 00 <41> bf fe ff ff ff 44 89 e9 41 d3 c7 49 83 c6 44 4c 89 f0 48 c1 e8
RSP: 0018:ffffc90000007d40 EFLAGS: 00000006
RAX: ffffffff81af2117 RBX: ffff8880b8628388 RCX: ffff88807c091e80
RDX: 0000000000010000 RSI: 0000000000000001 RDI: 0000000000000020
RBP: ffffc90000007e90 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e
R10: dffffc0000000000 R11: fffffbfff1f0454f R12: ffff88805a271300
R13: 0000000000000001 R14: ffff8880b8628240 R15: 0000000000000001
FS: 000055555a601500(0000) GS:ffff888125e31000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f48c0bfbd58 CR3: 0000000068c90000 CR4: 00000000003526f0
Call Trace:
hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline]
__sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lockdep_register_key+0x166/0x190 kernel/locking/lockdep.c:1244
Code: 03 00 00 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 28 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 05 4a 91 e0 10 <48> 3b 44 24 08 0f 84 43 ff ff ff e8 fa a1 bd 09 90 0f 0b 90 eb be
RSP: 0018:ffffc900038a6ae8 EFLAGS: 00000206
RAX: 5ec06e0b0bc22300 RBX: ffff888048dffa68 RCX: 5ec06e0b0bc22300
RDX: 0000000000000000 RSI: ffffffff8d7a85a8 RDI: ffffffff8bc08360
RBP: ffffffff8f82af60 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e
R10: dffffc0000000000 R11: fffffbfff1f0454f R12: ffff88802459e000
R13: dffffc0000000000 R14: 0000000000000246 R15: ffff888048dff8e0
qdisc_alloc+0x19b/0x910 net/sched/sch_generic.c:958
qdisc_create_dflt+0x8e/0x4c0 net/sched/sch_generic.c:1008
attach_one_default_qdisc net/sched/sch_generic.c:1174 [inline]
netdev_for_each_tx_queue include/linux/netdevice.h:2685 [inline]
attach_default_qdiscs net/sched/sch_generic.c:1192 [inline]
dev_activate+0x378/0x1150 net/sched/sch_generic.c:1251
__dev_open+0x647/0x800 net/core/dev.c:1692
__dev_change_flags+0x1f7/0x680 net/core/dev.c:9735
netif_change_flags+0x88/0x1a0 net/core/dev.c:9798
do_setlink+0xc55/0x41c0 net/core/rtnetlink.c:3158
rtnl_changelink net/core/rtnetlink.c:3776 [inline]
__rtnl_newlink net/core/rtnetlink.c:3935 [inline]
rtnl_newlink+0x161c/0x1c90 net/core/rtnetlink.c:4072
rtnetlink_rcv_msg+0x7cf/0xb70 net/core/rtnetlink.c:6958
netlink_rcv_skb+0x208/0x470 net/netlink/af_netlink.c:2550
netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline]
netlink_unicast+0x82f/0x9e0 net/netlink/af_netlink.c:1344
netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1894
sock_sendmsg_nosec+0x18f/0x1d0 net/socket.c:737
__sock_sendmsg net/socket.c:752 [inline]
__sys_sendto+0x3ce/0x540 net/socket.c:2221
__do_sys_sendto net/socket.c:2228 [inline]
__se_sys_sendto net/socket.c:2224 [inline]
__x64_sys_sendto+0xde/0x100 net/socket.c:2224
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f0a8b7915dc
Code: 2a 5f 02 00 44 8b 4c 24 2c 4c 8b 44 24 20 89 c5 44 8b 54 24 28 48 8b 54 24 18 b8 2c 00 00 00 48 8b 74 24 10 8b 7c 24 08 0f 05 <48> 3d 00 f0 ff ff 77 34 89 ef 48 89 44 24 08 e8 70 5f 02 00 48 8b
RSP: 002b:00007ffe2fee3890 EFLAGS: 00000293 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 00007f0a8c514620 RCX: 00007f0a8b7915dc
RDX: 000000000000002c RSI: 00007f0a8c514670 RDI: 0000000000000003
RBP: 0000000000000000 R08: 00007ffe2fee38e4 R09: 000000000000000c
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000003
R13: 0000000000000000 R14: 00007f0a8c514670 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 9850 jiffies! g450113 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:27200 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x14bc/0x5000 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0x165/0x360 kernel/sched/core.c:6960
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+0x599/0xb30 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 27663 Comm: syz.5.18119 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xccf/0x12b0 kernel/smp.c:877
Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 ea 96 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 95 92 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 79 92
RSP: 0018:ffffc900036a7320 EFLAGS: 00000293
RAX: ffffffff81b624d7 RBX: 1ffff110170c856d RCX: ffff88802f919e80
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900036a74a0 R08: ffffffff8f822a77 R09: 1ffffffff1f0454e
R10: dffffc0000000000 R11: fffffbfff1f0454f R12: ffff8880b8642b68
R13: dffffc0000000000 R14: ffff8880b873bb00 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff888125f31000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe917d8e008 CR3: 000000000dd3a000 CR4: 00000000003526f0
DR0: 000000000000a582 DR1: 0000000000000006 DR2: 0000000000000343
DR3: 000000000000000b DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
__flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline]
flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:502 [inline]
tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
tlb_finish_mmu+0xf9/0x230 mm/mmu_gather.c:503
free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411
arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline]
exit_mmap+0x174/0xb10 mm/mmap.c:1263
__mmput+0x118/0x430 kernel/fork.c:1173
exit_mm+0x1da/0x2c0 kernel/exit.c:581
do_exit+0x658/0x2310 kernel/exit.c:959
do_group_exit+0x21c/0x2d0 kernel/exit.c:1112
get_signal+0x1285/0x1340 kernel/signal.c:3034
arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:41 [inline]
exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f48bfd8f749
Code: Unable to access opcode bytes at 0x7f48bfd8f71f.
RSP: 002b:00007f48c0c1c038 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffff98 RBX: 00007f48bffe5fa0 RCX: 00007f48bfd8f749
RDX: 00002000000000c0 RSI: 0000200000000000 RDI: 0000000000000000
RBP: 00007f48bfe13f91 R08: 00002000000005c0 R09: 0000000000000000
R10: 0000000000008004 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f48bffe6038 R14: 00007f48bffe5fa0 R15: 00007ffebebf2548