rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 0-...!: (1 GPs behind) idle=b8fc/1/0x4000000000000000 softirq=77611/77611 fqs=1
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12504/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=77481, q=778 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 12187 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
RIP: 0010:lock_acquire+0x11b/0x350 kernel/locking/lockdep.c:5870
Code: 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 e8 da 02 00 00 48 83 c4 28 48 c7 c7 03 ed 4a 8e e8 aa 5e 2c 0a b8 ff ff ff ff <65> 0f c1 05 6d 80 ca 11 83 f8 01 0f 85 ae 00 00 00 9c 58 a9 00 02
RSP: 0018:ffffc90000007cb0 EFLAGS: 00000002
RAX: 00000000ffffffff RBX: 0000000000000000 RCX: 0000000080010002
RDX: 00000000125ddc43 RSI: ffffffff8e4aed03 RDI: ffffffff8c4bd280
RBP: ffffffff84ddd75a R08: ffffffff84ddd75a R09: 0000000000080000
R10: 0000000000000000 R11: ffffffff9aa74560 R12: 0000000000000000
R13: ffffffff9aa74560 R14: 0000000000000001 R15: 0000000000000046
FS: 0000555591bc2500(0000) GS:ffff888124f5a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c3038df CR3: 0000000074e30000 CR4: 0000000000350ef0
Call Trace:
__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+0x9a/0x250 lib/debugobjects.c:936
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:2000 [inline]
__hrtimer_run_queues+0x239/0xa10 kernel/time/hrtimer.c:2096
hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline]
__sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline]
sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_is_held_type+0x106/0x150 kernel/locking/lockdep.c:5945
Code: 1a 00 00 b8 ff ff ff ff 65 0f c1 05 b4 3c 9e 07 83 f8 01 75 25 9c 58 a9 00 02 00 00 75 39 41 f7 c4 00 02 00 00 74 01 fb 89 d8 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 a6 d8 41 f5 cc 90 0f 0b 90 48 c7
RSP: 0018:ffffc900058c7190 EFLAGS: 00000206
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 0000000000000000 RSI: ffffffff8e4aed03 RDI: ffffffff8c4bd280
RBP: 00000000ffffffff R08: ffff88804a5cf5cf R09: 1ffff110094b9eb9
R10: dffffc0000000000 R11: ffffed10094b9eba R12: 0000000000000246
R13: ffff888050235d00 R14: ffffffff8eb59d20 R15: 0000000000000006
lock_is_held include/linux/lockdep.h:249 [inline]
__might_resched+0x86/0x4d0 kernel/sched/core.c:9159
dput+0x23/0x60 fs/dcache.c:1039
debugfs_end_creating fs/debugfs/inode.c:412 [inline]
__debugfs_create_file+0x34f/0x400 fs/debugfs/inode.c:452
debugfs_create_file_unsafe+0x3a/0x50 fs/debugfs/inode.c:509
nsim_udp_tunnels_info_create+0x14e/0x630 drivers/net/netdevsim/udp_tunnels.c:145
nsim_init_netdevsim drivers/net/netdevsim/netdev.c:1054 [inline]
nsim_create+0x861/0x1150 drivers/net/netdevsim/netdev.c:1152
__nsim_dev_port_add+0x7f8/0xcd0 drivers/net/netdevsim/dev.c:1509
nsim_dev_port_add_all+0x37/0xf0 drivers/net/netdevsim/dev.c:1570
nsim_drv_probe+0x8ce/0xbf0 drivers/net/netdevsim/dev.c:1731
call_driver_probe drivers/base/dd.c:-1 [inline]
really_probe+0x254/0xae0 drivers/base/dd.c:706
__driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
__device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:500
__device_attach+0x2c4/0x450 drivers/base/dd.c:1098
device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
bus_probe_device+0x12a/0x220 drivers/base/bus.c:620
device_add+0x7d7/0xb80 drivers/base/core.c:3772
nsim_bus_dev_new drivers/net/netdevsim/bus.c:471 [inline]
new_device_store+0x37b/0x710 drivers/net/netdevsim/bus.c:191
kernfs_fop_write_iter+0x3a4/0x540 fs/kernfs/file.c:345
new_sync_write fs/read_write.c:595 [inline]
vfs_write+0x612/0xba0 fs/read_write.c:687
ksys_write+0x150/0x270 fs/read_write.c:739
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: 0033:0x7fe08315e68e
Code: 08 0f 85 a5 a8 ff ff 49 89 fb 48 89 f0 48 89 d7 48 89 ce 4c 89 c2 4d 89 ca 4c 8b 44 24 08 4c 8b 4c 24 10 4c 89 5c 24 08 0f 05 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 80 00 00 00 00 48 83 ec 08
RSP: 002b:00007ffe0c52d028 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000555591bc2500 RCX: 00007fe08315e68e
RDX: 0000000000000003 RSI: 00007ffe0c52d0b0 RDI: 0000000000000005
RBP: 00007fe083234716 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003
R13: 00007ffe0c52d0b0 R14: 00007fe083f54620 R15: 0000000000000003
task:dhcpcd-run-hook state:R running task stack:25872 pid:12504 tgid:12504 ppid:12474 task_flags:0x40004c flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7506
preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753
rcu_read_lock include/linux/rcupdate.h:841 [inline]
class_rcu_constructor include/linux/rcupdate.h:1183 [inline]
unwind_next_frame+0xbe/0x2550 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122
kasan_save_stack+0x3e/0x60 mm/kasan/common.c:57
kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:556
__call_rcu_common kernel/rcu/tree.c:3159 [inline]
call_rcu+0xee/0x8b0 kernel/rcu/tree.c:3279
slab_free_hook mm/slub.c:2669 [inline]
slab_free mm/slub.c:6405 [inline]
kmem_cache_free+0x462/0x650 mm/slub.c:6532
tear_down_vmas+0x312/0x520 mm/mmap.c:1262
exit_mmap+0x4ca/0x9f0 mm/mmap.c:1320
__mmput+0x118/0x420 kernel/fork.c:1187
exit_mm+0x221/0x2d0 kernel/exit.c:610
do_exit+0x6cd/0x2360 kernel/exit.c:992
do_group_exit+0x22d/0x2f0 kernel/exit.c:1147
__do_sys_exit_group kernel/exit.c:1158 [inline]
__se_sys_exit_group kernel/exit.c:1156 [inline]
__x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1156
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: 0033:0x7f068e0426c5
RSP: 002b:00007ffeb11b45a8 EFLAGS: 00000202 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 00007ffeb11b4804 RCX: 00007f068e0426c5
RDX: 00000000000000e7 RSI: ffffffffffffff88 RDI: 0000000000000000
RBP: 0000000000000003 R08: 00007ffeb11b46a0 R09: 0000000000000002
R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000000
R13: 00007ffeb11b48e0 R14: 00007f068e252000 R15: 000055da16a06d98
rcu: rcu_preempt kthread starved for 10500 jiffies! g77481 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:27752 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5510 [inline]
__schedule+0x17d9/0x56c0 kernel/sched/core.c:7234
__schedule_loop kernel/sched/core.c:7311 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7326
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325
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
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 8199 Comm: syz-executor Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
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+0x10b5/0x14b0 kernel/smp.c:892
Code: 1e 89 de 83 e6 01 31 ff e8 d8 1e 0c 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 84 1a 0c 00 eb 37 f3 90 41 0f b6 04 1c <84> c0 75 10 41 f7 06 01 00 00 00 74 1e e8 69 1a 0c 00 eb e5 44 89
RSP: 0018:ffffc9000ee7f580 EFLAGS: 00000293
RAX: 0000000000000000 RBX: dffffc0000000000 RCX: ffff888031be8000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: ffffc9000ee7f6a8 R08: ffffffff90576df7 R09: 1ffffffff20aedbe
R10: dffffc0000000000 R11: fffffbfff20aedbf R12: 1ffff110170c85fd
R13: ffff8880b873c448 R14: ffff8880b8642fe8 R15: 0000000000000000
FS: 0000555572744500(0000) GS:ffff88812505a000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f8cf4feb540 CR3: 0000000026ebb000 CR4: 0000000000350ef0
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+0x5c4/0x1090 arch/x86/mm/tlb.c:1451
dup_mmap+0x1786/0x1d90 mm/mmap.c:1905
dup_mm kernel/fork.c:1543 [inline]
copy_mm+0x11a/0x480 kernel/fork.c:1595
copy_process+0x1e3e/0x4390 kernel/fork.c:2289
kernel_clone+0x2d7/0x940 kernel/fork.c:2748
__do_sys_clone kernel/fork.c:2889 [inline]
__se_sys_clone kernel/fork.c:2873 [inline]
__x64_sys_clone+0x1b6/0x230 kernel/fork.c:2873
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: 0033:0x7f04e57c68d2
Code: 89 e7 e8 71 8b f7 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 66 89 c5 85 c0 75 3b 64 48 8b 04 25 10 00 00
RSP: 002b:00007ffe086d6590 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007ffe086d6590 RCX: 00007f04e57c68d2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007ffe086d671c R08: 0000000000000000 R09: 0000000000000001
R10: 00005555727447d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000094224 R15: 00007ffe086d6770