rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6400/1:b..l P18812/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=100809, q=499 ncpus=2)
task:syz.0.3370 state:R running task stack:26824 pid:18812 tgid:18807 ppid:17785 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x62/0x330 kernel/locking/lockdep.c:5872
Code: 36 18 12 83 f8 07 0f 87 a2 02 00 00 89 c0 48 0f a3 05 82 7f ee 0e 0f 82 74 02 00 00 8b 35 1a b0 ee 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 99 36 18 12 0f 85 ad 02 00 00 48 83 c4
RSP: 0018:ffffc900043bf6f0 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8e3c9620 RCX: 00000000dc432d69
RDX: 0000000000000000 RSI: ffffffff8daa55bb RDI: ffffffff8bf2a580
RBP: 0000000000000002 R08: 000000008aee58e5 R09: 0000000058aee58e
R10: 0000000000000002 R11: ffff888031de8b30 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
rcu_read_lock include/linux/rcupdate.h:867 [inline]
class_rcu_constructor include/linux/rcupdate.h:1195 [inline]
unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_save_track+0x14/0x30 mm/kasan/common.c:77
unpoison_slab_object mm/kasan/common.c:339 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:365
kasan_slab_alloc include/linux/kasan.h:252 [inline]
slab_post_alloc_hook mm/slub.c:4948 [inline]
kmem_cache_alloc_bulk_noprof+0x372/0x800 mm/slub.c:7514
__io_alloc_req_refill+0x9d/0x5e0 io_uring/io_uring.c:1025
io_alloc_req io_uring/io_uring.h:562 [inline]
io_submit_sqes+0xf94/0x28e0 io_uring/io_uring.c:2423
__do_sys_io_uring_enter+0xd6b/0x1630 io_uring/io_uring.c:3277
do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
do_syscall_64+0xcd/0xf80 arch/x86/entry/syscall_64.c:94
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fd5aa18f749
RSP: 002b:00007fd5a83d5038 EFLAGS: 00000246 ORIG_RAX: 00000000000001aa
RAX: ffffffffffffffda RBX: 00007fd5aa3e6180 RCX: 00007fd5aa18f749
RDX: 000000000000f400 RSI: 0000000000003516 RDI: 0000000000000006
RBP: 00007fd5aa213f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fd5aa3e6218 R14: 00007fd5aa3e6180 R15: 00007ffda0ab7a18
task:kworker/u8:21 state:R running task stack:23896 pid:6400 tgid:6400 ppid:2 task_flags:0x4208060 flags:0x00080000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7190
irqentry_exit+0x1d8/0x8c0 kernel/entry/common.c:216
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:68
Code: c7 c7 b8 80 8a 8b e8 5c 06 bc 00 e9 e8 fb ff ff 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 08 d8 0d 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc9000c8273f8 EFLAGS: 00000202
RAX: ffffffff826ba0eb RBX: 0000000000000001 RCX: ffffc9000c828000
RDX: ffffc9000c827801 RSI: ffffc9000c8278d0 RDI: ffffc9000c8278d0
RBP: ffffc9000c8274b8 R08: ffffffff9134f276 R09: 000000005ba6cd3b
R10: 0000000000000002 R11: 0000000000016b9f R12: ffffc9000c8274c0
R13: ffffc9000c827470 R14: ffffc9000c8278d8 R15: ffffc9000c8274a4
deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
unwind_next_frame+0xb8f/0x20a0 arch/x86/kernel/unwind_orc.c:585
arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
kasan_record_aux_stack+0xa7/0xc0 mm/kasan/generic.c:556
__call_rcu_common.constprop.0+0xa5/0xa10 kernel/rcu/tree.c:3119
kernfs_put.part.0+0x162/0x600 fs/kernfs/dir.c:591
kernfs_put fs/kernfs/dir.c:1727 [inline]
kernfs_remove_by_name_ns+0xdf/0x100 fs/kernfs/dir.c:1721
kernfs_remove_by_name include/linux/kernfs.h:633 [inline]
remove_files+0x96/0x1c0 fs/sysfs/group.c:28
sysfs_remove_group+0x8b/0x1b0 fs/sysfs/group.c:328
sysfs_remove_groups fs/sysfs/group.c:352 [inline]
sysfs_remove_groups+0x60/0xa0 fs/sysfs/group.c:344
destroy_gid_attrs drivers/infiniband/core/sysfs.c:1182 [inline]
ib_free_port_attrs+0x278/0x490 drivers/infiniband/core/sysfs.c:1407
remove_one_compat_dev drivers/infiniband/core/device.c:1038 [inline]
rdma_dev_exit_net+0x2b5/0x590 drivers/infiniband/core/device.c:1176
ops_exit_list net/core/net_namespace.c:199 [inline]
ops_undo_list+0x2ee/0xab0 net/core/net_namespace.c:252
cleanup_net+0x41b/0x830 net/core/net_namespace.c:696
process_one_work+0x9ba/0x1b20 kernel/workqueue.c:3257
process_scheduled_works kernel/workqueue.c:3340 [inline]
worker_thread+0x6c8/0xf10 kernel/workqueue.c:3421
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: rcu_preempt kthread starved for 10582 jiffies! g100809 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:28208 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5256 [inline]
__schedule+0x1139/0x6150 kernel/sched/core.c:6863
__schedule_loop kernel/sched/core.c:6945 [inline]
schedule+0xe7/0x3a0 kernel/sched/core.c:6960
schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083
rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285
kthread+0x3c5/0x780 kernel/kthread.c:463
ret_from_fork+0x983/0xb10 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 46 60 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 f9 12 00 fb f4 cc 35 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0000:ffffffff8e007df8 EFLAGS: 000002c6
RAX: 0000000005625af1 RBX: 0000000000000000 RCX: ffffffff8b7766d9
RDX: 0000000000000000 RSI: ffffffff8dacb65b RDI: ffffffff8bf2a580
RBP: fffffbfff1c12f68 R08: 0000000000000001 R09: ffffed101708673d
R10: ffff8880b84339eb R11: ffffffff8e098670 R12: 0000000000000000
R13: ffffffff8e097b40 R14: ffffffff908878d0 R15: 0000000000000000
FS: 0000000000000000(0000) GS:ffff8881248fd000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000001b2f013ff8 CR3: 000000004d187000 CR4: 00000000003526f0
Call Trace:
arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
default_idle+0x13/0x20 arch/x86/kernel/process.c:767
default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122
cpuidle_idle_call kernel/sched/idle.c:191 [inline]
do_idle+0x38d/0x510 kernel/sched/idle.c:332
cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:430
rest_init+0x16b/0x2b0 init/main.c:757
start_kernel+0x3ef/0x4d0 init/main.c:1206
x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:310
x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:291
common_startup_64+0x13e/0x148