rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 1-...!: (1 GPs behind) idle=78b/1/0x4000000000000000 softirq=82634/82635 fqs=6
(detected by 0, t=10502 jiffies, g=98933, q=343)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 PID: 4173 Comm: kworker/1:3 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Workqueue: events nsim_dev_trap_report_work
RIP: 0010:arch_test_and_set_bit arch/x86/include/asm/bitops.h:138 [inline]
RIP: 0010:test_and_set_bit include/asm-generic/bitops/instrumented-atomic.h:71 [inline]
RIP: 0010:__netif_schedule+0x99/0x2c0 net/core/dev.c:3104
Code: f3 f3 41 c6 44 0d 0b f3 e8 84 db a1 f9 48 8d bb 88 01 00 00 be 08 00 00 00 e8 33 45 e6 f9 31 f6 f0 48 0f ba ab 88 01 00 00 00 <41> 0f 93 c6 40 0f 92 c6 bf 02 00 00 00 e8 b5 dd a1 f9 45 84 f6 75
RSP: 0018:ffffc90000dd0ba0 EFLAGS: 00000047
RAX: ffffffff87d5f001 RBX: ffff888021308000 RCX: ffffffff87d5f09d
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff888021308188
RBP: ffffc90000dd0c70 R08: dffffc0000000000 R09: ffffed1004261032
R10: ffffed1004261032 R11: 1ffff11004261031 R12: ffff8880213082e8
R13: 1ffff920001ba178 R14: ffff888021308000 R15: 00493c0054000000
FS: 0000000000000000(0000) GS:ffff8880b9100000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c33e061 CR3: 00000000220f1000 CR4: 00000000003506e0
Call Trace:
advance_sched+0x74c/0x940 net/sched/sch_taprio.c:770
__run_hrtimer kernel/time/hrtimer.c:1685 [inline]
__hrtimer_run_queues+0x53d/0xc40 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 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+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:unwind_next_frame+0x8bb/0x1d90 arch/x86/kernel/unwind_orc.c:535
Code: 04 28 84 c0 0f 85 fa 12 00 00 4c 89 f8 48 c1 e8 03 42 0f b6 04 28 84 c0 0f 85 14 13 00 00 48 0f bf 02 48 01 c7 48 89 7c 24 08 <4d> 8d 7e 01 43 0f b6 04 2c 84 c0 0f 85 20 0f 00 00 4c 89 fa 48 c1
RSP: 0018:ffffc9000266f608 EFLAGS: 00000282
RAX: 0000000000000100 RBX: ffffc9000266f6c8 RCX: ffffffff8dacb4a0
RDX: ffffffff8e32c5ba RSI: ffffffff8e32c5ba RDI: ffffc9000266fc40
RBP: ffffc9000266f710 R08: 0000000000000001 R09: 0000000000000005
R10: fffff520004cdee5 R11: 1ffff920004cdee3 R12: 1ffffffff1c658b7
R13: dffffc0000000000 R14: ffffffff8e32c5be R15: ffffffff8e32c5bb
arch_stack_walk+0x10c/0x140 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x98/0xe0 kernel/stacktrace.c:122
kasan_save_stack mm/kasan/common.c:38 [inline]
kasan_set_track+0x4b/0x70 mm/kasan/common.c:46
kasan_set_free_info+0x1f/0x40 mm/kasan/generic.c:360
____kasan_slab_free+0xd5/0x110 mm/kasan/common.c:366
kasan_slab_free include/linux/kasan.h:230 [inline]
slab_free_hook mm/slub.c:1710 [inline]
slab_free_freelist_hook+0xea/0x170 mm/slub.c:1736
slab_free mm/slub.c:3504 [inline]
kmem_cache_free+0x8f/0x210 mm/slub.c:3520
nsim_dev_trap_report drivers/net/netdevsim/dev.c:737 [inline]
nsim_dev_trap_report_work+0x7cb/0xb40 drivers/net/netdevsim/dev.c:762
process_one_work+0x863/0x1000 kernel/workqueue.c:2310
worker_thread+0xaa8/0x12a0 kernel/workqueue.c:2457
kthread+0x436/0x520 kernel/kthread.c:334
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287
rcu: rcu_preempt kthread starved for 10490 jiffies! g98933 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:28064 pid: 15 ppid: 2 flags:0x00004000
Call Trace:
context_switch kernel/sched/core.c:5049 [inline]
__schedule+0x11bb/0x4390 kernel/sched/core.c:6395
schedule+0x11b/0x1e0 kernel/sched/core.c:6478
schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914
rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972
rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145
kthread+0x436/0x520 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:
NMI backtrace for cpu 0
CPU: 0 PID: 28505 Comm: syz.1.10608 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
Call Trace:
dump_stack_lvl+0x168/0x230 lib/dump_stack.c:106
nmi_cpu_backtrace+0x397/0x3d0 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_check_gp_kthread_starvation+0x1cd/0x250 kernel/rcu/tree_stall.h:487
print_other_cpu_stall+0x10c8/0x1220 kernel/rcu/tree_stall.h:592
check_cpu_stall kernel/rcu/tree_stall.h:745 [inline]
rcu_pending kernel/rcu/tree.c:3936 [inline]
rcu_sched_clock_irq+0x831/0x1110 kernel/rcu/tree.c:2619
update_process_times+0x193/0x200 kernel/time/timer.c:1818
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+0x4fe/0xc40 kernel/time/hrtimer.c:1749
hrtimer_interrupt+0x3bb/0x8d0 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+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1108
asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:csd_lock_wait kernel/smp.c:440 [inline]
RIP: 0010:smp_call_function_many_cond+0xb88/0xd70 kernel/smp.c:969
Code: b6 44 05 00 84 c0 0f 85 9d 00 00 00 41 8b 1c 24 89 de 83 e6 01 31 ff e8 66 49 0b 00 83 e3 01 75 07 e8 fc 45 0b 00 eb 43 f3 90 <48> b8 00 00 00 00 00 fc ff df 41 0f b6 44 05 00 84 c0 75 11 41 f7
RSP: 0018:ffffc90002e8f4e0 EFLAGS: 00000293
RAX: ffffffff816c863b RBX: 0000000000000001 RCX: ffff888079c88000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc90002e8f620 R08: dffffc0000000000 R09: ffffed101720767b
R10: ffffed101720767b R11: 1ffff1101720767a R12: ffff8880b91405c8
R13: 1ffff110172280b9 R14: ffff8880b903b3c0 R15: 0000000000000001
on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1134
__flush_tlb_multi arch/x86/include/asm/paravirt.h:87 [inline]
flush_tlb_multi arch/x86/mm/tlb.c:946 [inline]
flush_tlb_mm_range+0x360/0x560 arch/x86/mm/tlb.c:1034
tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
tlb_flush_mmu_tlbonly+0x1b1/0x3f0 include/asm-generic/tlb.h:430
tlb_flush_mmu mm/mmu_gather.c:246 [inline]
tlb_finish_mmu+0xc5/0x2e0 mm/mmu_gather.c:338
exit_mmap+0x3a6/0x5f0 mm/mmap.c:3218
__mmput+0x115/0x3b0 kernel/fork.c:1127
exit_mm+0x567/0x6c0 kernel/exit.c:550
do_exit+0x5a1/0x20a0 kernel/exit.c:870
do_group_exit+0x12e/0x300 kernel/exit.c:997
get_signal+0x6ca/0x12c0 kernel/signal.c:2900
arch_do_signal_or_restart+0xc1/0x1300 arch/x86/kernel/signal.c:867
handle_signal_work kernel/entry/common.c:154 [inline]
exit_to_user_mode_loop+0x9e/0x130 kernel/entry/common.c:178
exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
__syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7fbf3a6086c9
Code: Unable to access opcode bytes at RIP 0x7fbf3a60869f.
RSP: 002b:00007fbf3886f0e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007fbf3a85efa8 RCX: 00007fbf3a6086c9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fbf3a85efa8
RBP: 00007fbf3a85efa0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fbf3a85f038 R14: 00007ffea3b37750 R15: 00007ffea3b37838