rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13327/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=392481, q=786052 ncpus=2)
task:syz.1.13834 state:R running task stack:28320 pid:13327 tgid:13323 ppid:2078 task_flags:0x40054c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7513
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x8b0 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+0x20/0x40 kernel/rcu/update.c:321
Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 31 c0 83 3d e3 c7 88 04 00 74 1d 83 3d ba f9 88 04 00 74 14 65 48 8b 0d d8 c4 90 07 <31> c0 83 b9 8c 0b 00 00 00 0f 94 c0 c3 cc cc cc cc cc cc cc cc cc
RSP: 0018:ffffc9000dff74f0 EFLAGS: 00000202
RAX: 0000000000000000 RBX: ffffffff81000130 RCX: ffff88802e970000
RDX: 00000000d9196744 RSI: ffffffff8e215f65 RDI: ffffffff8c28b760
RBP: dffffc0000000000 R08: ffffffff8176e256 R09: ffffffff8e95cce0
R10: ffffc9000dff7618 R11: ffffffff81b0e210 R12: ffffc9000dff7600
R13: 1ffff92001bfeeb9 R14: ffffc9000dff75c8 R15: ffffffff8176e256
rcu_read_lock include/linux/rcupdate.h:839 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xcc/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
save_stack+0x122/0x230 mm/page_owner.c:165
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:320
reset_page_owner include/linux/page_owner.h:25 [inline]
__free_pages_prepare mm/page_alloc.c:1397 [inline]
__free_frozen_pages+0xc1c/0xd30 mm/page_alloc.c:2938
__slab_free+0x274/0x2c0 mm/slub.c:5613
qlink_free mm/kasan/quarantine.c:163 [inline]
qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179
kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
__kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4906
taskstats_tgid_alloc kernel/taskstats.c:576 [inline]
taskstats_exit+0x14a/0xa70 kernel/taskstats.c:615
do_exit+0x682/0x22c0 kernel/exit.c:946
do_group_exit+0x21b/0x2d0 kernel/exit.c:1119
get_signal+0x1284/0x1330 kernel/signal.c:3037
arch_do_signal_or_restart+0xbc/0x840 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0xa9/0x680 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+0x353/0x580 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fa68c59ce59
RSP: 002b:00007fa68d43e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000116
RAX: fffffffffffffe00 RBX: 00007fa68c815fa0 RCX: 00007fa68c59ce59
RDX: 0000000000000001 RSI: 0000200000000500 RDI: 0000000000000006
RBP: 00007fa68c632d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fa68c816038 R14: 00007fa68c815fa0 R15: 00007fa68c93fa48
rcu: rcu_preempt kthread starved for 838 jiffies! g392481 f0x2 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:27640 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5388 [inline]
__schedule+0x1821/0x5740 kernel/sched/core.c:7189
__schedule_loop kernel/sched/core.c:7268 [inline]
schedule+0x164/0x360 kernel/sched/core.c:7283
schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x312/0x11d0 kernel/rcu/tree.c:2095
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2297
kthread+0x389/0x470 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 30852 Comm: kworker/u8:0 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Workqueue: krds_cp_wq#7/5 rds_connect_worker
RIP: 0010:check_preemption_disabled+0x1d/0xe0 lib/smp_processor_id.c:53
Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 55 41 57 41 56 53 65 8b 05 b7 ad 90 07 65 8b 0d ac ad 90 07 f7 c1 ff ff ff 7f 74 0c 5b <41> 5e 41 5f 5d e9 c9 d7 02 00 cc 9c 59 f7 c1 00 02 00 00 74 ea 65
RSP: 0018:ffffc90000007558 EFLAGS: 00000206
RAX: 0000000000000000 RBX: ffffffff81b1adca RCX: 0000000080000103
RDX: 00000000a7918ab0 RSI: ffffffff8c28b740 RDI: ffffffff8c28b700
RBP: dffffc0000000000 R08: ffffffff8176e256 R09: ffffffff8e95cce0
R10: ffffc900000076b8 R11: ffffffff81b0e210 R12: ffffc900000076a0
R13: 1ffff92000000ecd R14: ffffc90000007668 R15: ffffffff8176e256
FS: 0000000000000000(0000) GS:ffff88812529e000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000555592c154e8 CR3: 000000007e23e000 CR4: 00000000003526f0
DR0: 0000000000000004 DR1: 0000000000000000 DR2: 0000000000000000
DR3: ffffffffefffff14 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:752
rcu_read_lock include/linux/rcupdate.h:839 [inline]
class_rcu_constructor include/linux/rcupdate.h:1181 [inline]
unwind_next_frame+0xd5/0x2550 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 mm/kasan/common.c:57 [inline]
kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4570 [inline]
slab_alloc_node mm/slub.c:4899 [inline]
kmem_cache_alloc_noprof+0x2bc/0x650 mm/slub.c:4906
kmem_alloc_batch lib/debugobjects.c:371 [inline]
fill_pool+0x156/0x580 lib/debugobjects.c:420
debug_objects_fill_pool lib/debugobjects.c:752 [inline]
debug_object_assert_init+0x367/0x3b0 lib/debugobjects.c:1030
debug_timer_assert_init kernel/time/timer.c:803 [inline]
debug_assert_init kernel/time/timer.c:848 [inline]
__mod_timer+0x4a/0xf30 kernel/time/timer.c:1025
pie_timer+0x20a/0x360 net/sched/sch_pie.c:438
call_timer_fn+0x192/0x5e0 kernel/time/timer.c:1748
expire_timers kernel/time/timer.c:1799 [inline]
__run_timers kernel/time/timer.c:2374 [inline]
__run_timer_base+0x652/0x8b0 kernel/time/timer.c:2386
run_timer_base kernel/time/timer.c:2395 [inline]
run_timer_softirq+0xb7/0x170 kernel/time/timer.c:2405
handle_softirqs+0x22a/0x840 kernel/softirq.c:622
do_softirq+0x76/0xd0 kernel/softirq.c:523
__local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450
lock_sock include/net/sock.h:1713 [inline]
__inet6_bind+0x30c/0xf60 net/ipv6/af_inet6.c:292
kernel_bind+0x13e/0x1c0 net/socket.c:3660
rds_tcp_conn_path_connect+0x53e/0x930 net/rds/tcp_connect.c:175
rds_connect_worker+0x1d8/0x290 net/rds/threads.c:176
process_one_work kernel/workqueue.c:3314 [inline]
process_scheduled_works+0xb5d/0x1860 kernel/workqueue.c:3397
worker_thread+0xa53/0xfc0 kernel/workqueue.c:3478
kthread+0x389/0x470 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