rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=8494/1/0x4000000000000000 softirq=54850/54850 fqs=2
rcu: (detected by 0, t=10502 jiffies, g=64561, q=291 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 14933 Comm: syz.2.2428 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:mark_lock+0xf/0x190 kernel/locking/lockdep.c:4722
Code: e9 b6 fd ff ff 66 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 41 55 41 54 53 8b 46 20 89 c1 <81> e1 00 00 03 00 83 f9 01 bb 09 00 00 00 83 db 00 83 fa 08 0f 45
RSP: 0018:ffffc90000a08b48 EFLAGS: 00000006
RAX: 00000000000c4000 RBX: ffff888031206928 RCX: 00000000000c4000
RDX: 0000000000000008 RSI: ffff888031206908 RDI: ffff888031205d00
RBP: 0000000000000000 R08: ffffffff84bc8cfc R09: ffffffff9a725c80
R10: ffff888031f01308 R11: ffffed10063e0263 R12: 0000000000000002
R13: ffff888031206908 R14: ffff888031205d00 R15: 0000000000000003
FS: 00007f3e654bf6c0(0000) GS:ffff8881253a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00002000000012c0 CR3: 000000007d3cc000 CR4: 00000000003526f0
Call Trace:
mark_usage kernel/locking/lockdep.c:4674 [inline]
__lock_acquire+0x6b5/0x2cf0 kernel/locking/lockdep.c:5191
lock_acquire+0x106/0x350 kernel/locking/lockdep.c:5868
__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
_raw_spin_lock_irqsave+0x40/0x60 kernel/locking/spinlock.c:166
debug_object_deactivate+0x6c/0x3a0 lib/debugobjects.c:900
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:1898 [inline]
__hrtimer_run_queues+0x23a/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
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 9d 38 f8 f5 f7 c3 00 02 00 00 74 05 e8 e0 d2 23 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b4 b7 e9 f5 65 8b 05 ad ee 8d 07 85 c0 74 18 5b 41 5e e9 51 48
RSP: 0018:ffffc9000d7ceee8 EFLAGS: 00000206
RAX: 0000000000000006 RBX: 0000000000000282 RCX: 0000000000000202
RDX: 0000000000000002 RSI: ffffffff8dfa4d4f RDI: 0000000000000001
RBP: ffffc9000d7cf1d0 R08: ffffffff903034f7 R09: 1ffffffff206069e
R10: dffffc0000000000 R11: fffffbfff206069f R12: ffff888031f01290
R13: dffffc0000000000 R14: ffff888031f012a8 R15: ffff888031f012f8
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:7006
netlink_rcv_skb+0x232/0x4b0 net/netlink/af_netlink.c:2555
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:1899
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 net/socket.c:2784 [inline]
__do_sys_sendmsg net/socket.c:2789 [inline]
__se_sys_sendmsg net/socket.c:2787 [inline]
__x64_sys_sendmsg+0x1bd/0x2a0 net/socket.c:2787
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f3e6459ce59
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:00007f3e654bf028 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 00007f3e64815fa0 RCX: 00007f3e6459ce59
RDX: 0000000000008014 RSI: 00002000000012c0 RDI: 0000000000000006
RBP: 00007f3e64632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f3e64816038 R14: 00007f3e64815fa0 R15: 00007ffcad1050d8
rcu: rcu_preempt kthread starved for 10498 jiffies! g64561 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:27544 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
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+0x389/0x470 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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 14915 Comm: syz.1.2424 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xfcf/0x13d0 kernel/smp.c:892
Code: 79 45 8b 2e 44 89 ee 83 e6 01 31 ff e8 aa 07 0c 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 55 03 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 3a 03 0c
RSP: 0018:ffffc900104a77c0 EFLAGS: 00000293
RAX: ffffffff81b9b376 RBX: ffff8880b863c388 RCX: ffff8880555f5d00
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc900104a7900 R08: ffff88807bea3047 R09: 1ffff1100f7d4608
R10: dffffc0000000000 R11: ffffed100f7d4609 R12: 1ffff110170e81b1
R13: dffffc0000000000 R14: ffff8880b8740d88 R15: 0000000000000001
FS: 0000000000000000(0000) GS:ffff8881252a0000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000000 CR3: 000000005b4e4000 CR4: 00000000003526f0
Call Trace:
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
exit_mmap+0x498/0x9e0 mm/mmap.c:1313
__mmput+0x118/0x430 kernel/fork.c:1178
exit_mm+0x1f6/0x2d0 kernel/exit.c:582
do_exit+0x6a2/0x22c0 kernel/exit.c:964
do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
__do_sys_exit_group kernel/exit.c:1130 [inline]
__se_sys_exit_group kernel/exit.c:1128 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1128
x64_sys_call+0x221a/0x2240 arch/x86/include/generated/asm/syscalls_64.h:232
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff0c359ce59
Code: Unable to access opcode bytes at 0x7ff0c359ce2f.
RSP: 002b:00007ffee91e1258 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007ff0c359ce59
RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffee91e12bc R08: 0000000000000000 R09: 00000000000927c0
R10: 00007ff0c3816038 R11: 0000000000000246 R12: 00000000000001de
R13: 00000000000927c0 R14: 000000000004c136 R15: 00007ffee91e1310