rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5819/1:b..l
rcu: (detected by 0, t=10503 jiffies, g=38117, q=1312 ncpus=2)
task:syz-executor state:R running task stack:24136 pid:5819 tgid:5819 ppid:1 task_flags:0x40054c flags:0x00080002
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7238
irqentry_exit+0x17b/0x670 kernel/entry/common.c:239
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:pte_lockptr include/linux/mm.h:3474 [inline]
RIP: 0010:pte_offset_map_lock+0xdd/0x320 mm/pgtable-generic.c:401
Code: 0f 85 f7 00 00 00 e8 d2 27 a9 ff 48 c7 c0 28 0f 12 8e 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 0e 02 00 00 <4c> 03 3d d4 66 b2 0b 48 b8 00 00 00 00 00 fc ff df 49 8d 7f 28 48
RSP: 0018:ffffc90003fd7478 EFLAGS: 00000246
RAX: 1ffffffff1c241e5 RBX: 0000000064f90067 RCX: ffffffff825fa94e
RDX: dffffc0000000000 RSI: ffffffff825fa82e RDI: ffff888077980000
RBP: ffff888064f85fd0 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffff888064f90000
R13: 1ffff920007fae91 R14: ffffc90003fd7670 R15: 000000000193e400
zap_pte_range mm/memory.c:1915 [inline]
zap_pmd_range mm/memory.c:2021 [inline]
zap_pud_range mm/memory.c:2049 [inline]
zap_p4d_range mm/memory.c:2070 [inline]
unmap_page_range+0xb85/0x4840 mm/memory.c:2091
unmap_single_vma+0x153/0x240 mm/memory.c:2133
unmap_vmas+0x295/0x590 mm/memory.c:2171
exit_mmap+0x1ef/0xa30 mm/mmap.c:1302
__mmput+0x12a/0x410 kernel/fork.c:1175
mmput+0x67/0x80 kernel/fork.c:1198
exit_mm kernel/exit.c:581 [inline]
do_exit+0x819/0x2b60 kernel/exit.c:964
do_group_exit+0xd5/0x2a0 kernel/exit.c:1118
get_signal+0x1ec7/0x21e0 kernel/signal.c:3034
arch_do_signal_or_restart+0x91/0x7a0 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:64 [inline]
exit_to_user_mode_loop+0x86/0x4a0 kernel/entry/common.c:98
__exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
syscall_exit_to_user_mode include/linux/entry-common.h:325 [inline]
do_syscall_64+0x67c/0xf80 arch/x86/entry/syscall_64.c:100
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f013f75cfce
RSP: 002b:00007ffd278acb38 EFLAGS: 00000246 ORIG_RAX: 00000000000000e6
RAX: 0000000000000000 RBX: 0000555574bfb500 RCX: 00007f013f75cfce
RDX: 00007ffd278acb90 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 00007ffd278acbfc R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000109
R13: 0000000000000050 R14: 000000000008e0c6 R15: 00007ffd278acc50
rcu: rcu_preempt kthread starved for 344 jiffies! g38117 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:27832 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5298 [inline]
__schedule+0xfee/0x6120 kernel/sched/core.c:6911
__schedule_loop kernel/sched/core.c:6993 [inline]
schedule+0xdd/0x390 kernel/sched/core.c:7008
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+0x754/0xd80 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 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 85 Comm: kworker/u8:5 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline]
RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline]
RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline]
RIP: 0010:rcu_is_watching+0x55/0xc0 kernel/rcu/tree.c:752
Code: 8e 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 75 5c 48 03 1c ed e0 98 12 8e 48 b8 00 00 00 00 00 fc ff df <48> 89 da 48 c1 ea 03 0f b6 14 02 48 89 d8 83 e0 07 83 c0 03 38 d0
RSP: 0018:ffffc90000a08038 EFLAGS: 00000283
RAX: dffffc0000000000 RBX: ffff8880b8533ca8 RCX: 0000000000000007
RDX: 1ffffffff1c2531d RSI: ffffffff8c1b0aa0 RDI: ffffffff8e1298e8
RBP: 0000000000000001 R08: 000000005970cd9e R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000000000 R12: ffffffff81f35b50
R13: ffffc90000a080c0 R14: 0000000000000000 R15: ffff88801e78c980
FS: 0000000000000000(0000) GS:ffff888124442000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe39eeaf00 CR3: 00000000360a7000 CR4: 00000000003526f0
Call Trace:
rcu_read_lock include/linux/rcupdate.h:851 [inline]
class_rcu_constructor include/linux/rcupdate.h:1193 [inline]
unwind_next_frame+0x6fa/0x1ea0 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_save_track+0x14/0x30 mm/kasan/common.c:78
unpoison_slab_object mm/kasan/common.c:340 [inline]
__kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:366
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4538 [inline]
slab_alloc_node mm/slub.c:4866 [inline]
kmem_cache_alloc_node_noprof+0x25a/0x6f0 mm/slub.c:4918
__alloc_skb+0x140/0x710 net/core/skbuff.c:702
alloc_skb include/linux/skbuff.h:1383 [inline]
synproxy_send_client_synack_ipv6+0x19f/0x7a0 net/netfilter/nf_synproxy_core.c:874
nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:91 [inline]
nft_synproxy_do_eval+0x941/0xd50 net/netfilter/nft_synproxy.c:146
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x2e8/0x1930 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0xee/0x340 net/netfilter/nft_chain_filter.c:161
nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623
nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:273
NF_HOOK include/linux/netfilter.h:316 [inline]
ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:500
dst_input include/net/dst.h:480 [inline]
ip6_rcv_finish net/ipv6/ip6_input.c:79 [inline]
NF_HOOK include/linux/netfilter.h:318 [inline]
NF_HOOK include/linux/netfilter.h:312 [inline]
ipv6_rcv+0x263/0x3d0 net/ipv6/ip6_input.c:311
__netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6164
__netif_receive_skb+0x1f/0x120 net/core/dev.c:6277
process_backlog+0x37a/0x1580 net/core/dev.c:6628
__napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7692
napi_poll net/core/dev.c:7755 [inline]
net_rx_action+0xa40/0xf20 net/core/dev.c:7912
handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622
do_softirq kernel/softirq.c:523 [inline]
do_softirq+0xac/0xe0 kernel/softirq.c:510
__local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450
spin_unlock_bh include/linux/spinlock.h:395 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:891 [inline]
nsim_dev_trap_report_work+0x8c7/0xd10 drivers/net/netdevsim/dev.c:922
process_one_work+0xa23/0x19a0 kernel/workqueue.c:3276
process_scheduled_works kernel/workqueue.c:3359 [inline]
worker_thread+0x5ef/0xe50 kernel/workqueue.c:3440
kthread+0x370/0x450 kernel/kthread.c:436
ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158
ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245