rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1):
P12/1:b..l
rcu: (detected by 0, t=10506 jiffies, g=19777, q=1414 ncpus=2)
task:kworker/u8:0 state:R
running task
stack:24064 pid:12 tgid:12 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
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+0x205/0x970 kernel/entry/common.c:164
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417
Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 db 3d e9 f5 cc
RSP: 0018:ffffc90000117958 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff82b93013
RDX: ffff88801e2a4a80 RSI: ffffffff82b930c9 RDI: ffff88801e2a4a80
RBP: ffff88801c6a7800 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000001
R13: ffffffff8d0920c0 R14: 0000000000000000 R15: ffff88802669ce40
rcu_read_unlock include/linux/rcupdate.h:867 [inline]
class_rcu_destructor include/linux/rcupdate.h:1181 [inline]
kernfs_root+0x189/0x2a0 fs/kernfs/kernfs-internal.h:74
kernfs_remove_by_name_ns+0x30/0x120 fs/kernfs/dir.c:1791
kernfs_remove_by_name include/linux/kernfs.h:639 [inline]
remove_files+0x96/0x1c0 fs/sysfs/group.c:28
sysfs_remove_group+0x8b/0x1b0 fs/sysfs/group.c:328
br_dev_delete+0x11e/0x1a0 net/bridge/br_if.c:396
br_net_exit_rtnl+0xdb/0x140 net/bridge/br.c:414
ops_exit_rtnl_list net/core/net_namespace.c:181 [inline]
ops_undo_list+0x896/0xab0 net/core/net_namespace.c:248
cleanup_net+0x499/0x920 net/core/net_namespace.c:702
process_one_work+0xa0e/0x1980 kernel/workqueue.c:3314
process_scheduled_works kernel/workqueue.c:3397 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3478
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: rcu_preempt kthread starved for 3761 jiffies! g19777 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:28216 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:
CPU: 0 UID: 0 PID: 6574 Comm: syz.0.27 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
RIP: 0010:write_comp_data+0x40/0x90 kernel/kcov.c:246
Code: 01 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 c3 cc cc cc cc 8b 87 ec 16 00 00 85 c0 74 f1 8b 87 c8 16 00 00 <83> f8 03 75 e6 48 8b 87 d0 16 00 00 8b bf cc 16 00 00 48 8b 30 48
RSP: 0018:ffffc90004627648 EFLAGS: 00000246
RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffffffff81fc0d0d
RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88801ebf8000
RBP: ffff8880b8540f80 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000000 R12: 0000000000000003
R13: ffffed10170a81f1 R14: 0000000000000001 R15: ffff8880b843c600
FS: 0000000000000000(0000) GS:ffff888124386000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffc6cb9d58 CR3: 000000002ea0f000 CR4: 00000000003526f0
Call Trace:
csd_lock_wait kernel/smp.c:342 [inline]
smp_call_function_many_cond+0x5ad/0x1700 kernel/smp.c:892
on_each_cpu_cond_mask+0x40/0x90 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+0x45f/0x16f0 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_tlbonly include/asm-generic/tlb.h:499 [inline]
tlb_flush_mmu mm/mmu_gather.c:423 [inline]
tlb_finish_mmu+0x3fe/0x810 mm/mmu_gather.c:549
exit_mmap+0x454/0xa10 mm/mmap.c:1313
__mmput+0x12a/0x410 kernel/fork.c:1178
mmput+0x67/0x80 kernel/fork.c:1201
exit_mm kernel/exit.c:582 [inline]
do_exit+0x8b2/0x2af0 kernel/exit.c:964
do_group_exit+0xd5/0x2a0 kernel/exit.c:1119
get_signal+0x20ff/0x2210 kernel/signal.c:3037
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+0x98/0x670 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+0x666/0x870 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fe28e59caeb
Code: Unable to access opcode bytes at 0x7fe28e59cac1.
RSP: 002b:00007fe28f4f7f60 EFLAGS: 00000246
ORIG_RAX: 0000000000000010
RAX: fffffffffffffffc RBX: 00000000ffffff75 RCX: 00007fe28e59caeb
RDX: 00007fe28f4f7fe0 RSI: 0000000040085507 RDI: 0000000000000003
RBP: 0000000000000003 R08: 00007fe28e940320 R09: 0000000000000000
R10: 0000000000000003 R11: 0000000000000246 R12: 00002000000002c0
R13: 0000000000000000 R14: 00007fe28e815fa0 R15: 00007fff186de9c8