rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9846/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=54649, q=199 ncpus=2)
task:syz.1.1224 state:R running task stack:26056 pid:9846 tgid:9844 ppid:5609 task_flags:0x480140 flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x205/0x7e0 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:debug_lockdep_rcu_enabled+0x0/0x40 kernel/rcu/update.c:319
Code: 00 00 8b 44 24 04 eb b2 89 44 24 04 e8 a9 fa ff ff 8b 44 24 04 eb aa 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 8b 05 22 ed 4c 05 85 c0 74 20 8b 05 c0 1f 4d 05 85 c0
RSP: 0018:ffffc900034df4d0 EFLAGS: 00000287
RAX: ffffc900034e0001 RBX: ffffc900034dfd90 RCX: ffffffff9207dd01
RDX: ffffc900034dfd98 RSI: ffffc900034dfd60 RDI: ffffc900034df558
RBP: 0000000000000001 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000085e7a R12: ffffc900034df598
R13: ffffc900034df548 R14: ffffc900034dfd90 R15: ffffc900034df57c
rcu_read_unlock include/linux/rcupdate.h:867 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0x3a8/0x2090 arch/x86/kernel/unwind_orc.c:495
arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x30/0x50 mm/kasan/common.c:57
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
__call_rcu_common.constprop.0+0xa5/0x9b0 kernel/rcu/tree.c:3131
kernfs_put.part.0+0x22f/0x720 fs/kernfs/dir.c:618
kernfs_put+0x53/0x60 fs/kernfs/dir.c:629
sysfs_remove_group+0xc6/0x1b0 fs/sysfs/group.c:332
dpm_sysfs_remove+0x9d/0xb0 drivers/base/power/sysfs.c:834
device_del+0x180/0x9b0 drivers/base/core.c:3870
unregister_netdevice_many_notify+0x179e/0x24f0 net/core/dev.c:12456
ops_exit_rtnl_list net/core/net_namespace.c:187 [inline]
ops_undo_list+0x8ff/0xab0 net/core/net_namespace.c:248
setup_net+0x1fa/0x3a0 net/core/net_namespace.c:462
copy_net_ns+0x46f/0x7c0 net/core/net_namespace.c:579
create_new_namespaces+0x3ea/0xac0 kernel/nsproxy.c:132
unshare_nsproxy_namespaces+0xf2/0x220 kernel/nsproxy.c:234
ksys_unshare+0x438/0xab0 kernel/fork.c:3243
__do_sys_unshare kernel/fork.c:3317 [inline]
__se_sys_unshare kernel/fork.c:3315 [inline]
__x64_sys_unshare+0x31/0x40 kernel/fork.c:3315
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0x10b/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f5673f9ce59
RSP: 002b:00007f5674f29028 EFLAGS: 00000246 ORIG_RAX: 0000000000000110
RAX: ffffffffffffffda RBX: 00007f5674215fa0 RCX: 00007f5673f9ce59
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000064000600
RBP: 00007f5674032d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f5674216038 R14: 00007f5674215fa0 R15: 00007ffebbcd9d18
rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g54649 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: Possible timer handling issue on cpu=0 timer-softirq=17007
rcu: rcu_preempt kthread starved for 10502 jiffies! g54649 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28904 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1295/0x67a0 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7283
schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x72b/0xd50 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 9913 Comm: syz.2.1245 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:__raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
RIP: 0010:_raw_spin_lock_irqsave+0x33/0x60 kernel/locking/spinlock.c:166
Code: 9c 5d fa f7 c5 00 02 00 00 75 39 bf 01 00 00 00 e8 62 40 47 f6 ff 74 24 10 48 8d 7b 18 45 31 c9 31 c9 41 b8 01 00 00 00 31 d2 <31> f6 e8 a6 bf 56 f6 48 89 df e8 ee 10 57 f6 58 48 89 e8 5b 5d c3
RSP: 0018:ffffc90000007d80 EFLAGS: 00000046
RAX: 0000000000010003 RBX: ffffffff9b3a22f8 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8bb2dde0 RDI: ffffffff9b3a2310
RBP: 0000000000000006 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffffffff9b3a22f0
R13: dffffc0000000000 R14: ffff8880350ff300 R15: 1ffff92000000fb6
FS: 000055558b128500(0000) GS:ffff88812436d000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000110c273b73 CR3: 000000007c11f000 CR4: 00000000003526f0
Call Trace:
debug_object_deactivate+0x135/0x3b0 lib/debugobjects.c:890
debug_hrtimer_deactivate kernel/time/hrtimer.c:490 [inline]
__run_hrtimer kernel/time/hrtimer.c:1898 [inline]
__hrtimer_run_queues+0x2f0/0xa00 kernel/time/hrtimer.c:1994
hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2113
local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
__sysvec_apic_timer_interrupt+0x10b/0x460 arch/x86/kernel/apic/apic.c:1067
instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline]
sysvec_apic_timer_interrupt+0x9e/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_irq include/linux/spinlock_api_smp.h:188 [inline]
RIP: 0010:_raw_spin_unlock_irq+0x29/0x50 kernel/locking/spinlock.c:206
Code: 90 f3 0f 1e fa 53 48 8b 74 24 08 48 89 fb 48 83 c7 18 e8 aa c2 56 f6 48 89 df e8 82 12 57 f6 e8 8d 20 83 f6 fb bf 01 00 00 00 12 dc 46 f6 65 8b 05 8b 5f 7d 08 85 c0 74 06 5b c3 cc cc cc cc
RSP: 0018:ffffc9000343fc88 EFLAGS: 00000202
RAX: 0000000000005501 RBX: ffff88801ff43780 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8df223d3 RDI: 0000000000000001
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000021
R13: ffff88801ff43b80 R14: ffff88801ff43780 R15: ffff88801ff43c18
spin_unlock_irq include/linux/spinlock.h:402 [inline]
get_signal+0x19d0/0x2210 kernel/signal.c:3040
arch_do_signal_or_restart+0x91/0x7e0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x8b/0x4f0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline]
do_syscall_64+0x706/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f55def9ce59
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:00007fff8a558948 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffdfc RBX: 000000000004d33b RCX: 00007f55def9ce59
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f55df215fac
RBP: 0000000000000032 R08: 0000000000000001 R09: 0000000000000000
R10: 00007fff8a558a50 R11: 0000000000000246 R12: 00007fff8a558a70
R13: 00007f55df215fac R14: 000000000004d36d R15: 00007fff8a558a50