rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9699/1:b..l
rcu: (detected by 1, t=10503 jiffies, g=53245, q=795 ncpus=2)
task:syz.0.1233 state:R running task stack:25616 pid:9699 tgid:9666 ppid:5633 task_flags:0x40054c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17d4/0x5820 kernel/sched/core.c:7270
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7592
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
irqentry_exit+0x14f/0x910 kernel/entry/common.c:167
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:118 [inline]
RIP: 0010:lock_acquire+0x8b/0x350 kernel/locking/lockdep.c:5862
Code: 0f 84 cb 01 00 00 83 3d 22 28 d7 0e 00 0f 84 d3 00 00 00 48 8b b4 24 90 00 00 00 4c 89 ef e8 0c 21 94 00 83 3d 05 28 d7 0e 00 <0f> 84 ce 00 00 00 65 8b 05 30 cf f0 11 85 c0 0f 85 bf 00 00 00 65
RSP: 0018:ffffc90005886d40 EFLAGS: 00000202
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 8000000000000001
RDX: 0000000000000000 RSI: ffffffff8177f12c RDI: 1ffffffff1dab8d4
RBP: ffffffff8177f10f R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90005886ed8 R11: ffffffff81b26d80 R12: 0000000000000002
R13: ffffffff8ed5c6a0 R14: 0000000000000000 R15: 0000000000000000
rcu_lock_acquire include/linux/rcupdate.h:309 [inline]
rcu_read_lock include/linux/rcupdate.h:849 [inline]
class_rcu_constructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0xac/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:183
__reset_page_owner+0x71/0x1f0 mm/page_owner.c:338
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1418 [inline]
free_unref_folios+0xdc2/0x14e0 mm/page_alloc.c:3022
folios_put_refs+0x9e9/0xb30 mm/folio.c:1055
folio_batch_release include/linux/folio_batch.h:101 [inline]
shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1160
shmem_truncate_range mm/shmem.c:1288 [inline]
shmem_evict_inode+0x247/0xae0 mm/shmem.c:1419
evict+0x624/0xb50 fs/inode.c:822
dentry_kill+0x1b9/0x880 fs/dcache.c:826
finish_dput+0x1a/0x260 fs/dcache.c:1001
__fput+0x675/0xa50 fs/file_table.c:520
task_work_run+0x1d9/0x270 kernel/task_work.c:233
exit_task_work include/linux/task_work.h:40 [inline]
do_exit+0x73a/0x2360 kernel/exit.c:1008
do_group_exit+0x22d/0x2f0 kernel/exit.c:1151
get_signal+0x121b/0x12c0 kernel/signal.c:3039
arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337
__exit_to_user_mode_loop kernel/entry/common.c:66 [inline]
exit_to_user_mode_loop+0x10e/0x770 kernel/entry/common.c:101
__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:336 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f80a839e0d9
RSP: 002b:00007f80a92780e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
RAX: fffffffffffffe00 RBX: 00007f80a8626098 RCX: 00007f80a839e0d9
RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f80a8626098
RBP: 00007f80a8626090 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f80a8626128 R14: 00007f80a874f960 R15: 00007f80a874fa48
rcu: rcu_preempt kthread starved for 863 jiffies! g53245 f0x0 RCU_GP_WAIT_FQS(5) ->state=R ->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:26848 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5520 [inline]
__schedule+0x17d4/0x5820 kernel/sched/core.c:7270
__schedule_loop kernel/sched/core.c:7347 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7362
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2330
kthread+0x38b/0x480 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:
CPU: 1 UID: 0 PID: 9718 Comm: kworker/u8:14 Tainted: G L syzkaller #0 PREEMPT(full)
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:kasan_check_range+0x1c8/0x2c0 mm/kasan/generic.c:200
Code: 49 01 dc 4d 01 f3 49 8d 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 0e 41 80 3b 00 75 7c 49 ff c3 49 ff cc 75 f2 5b <41> 5c 41 5d 41 5e 41 5f 5d e9 4a 81 ad 09 cc 45 84 ff 0f 85 a1 00
RSP: 0018:ffffc90000a17e50 EFLAGS: 00000256
RAX: ffffc90000a18901 RBX: 0000000000000010 RCX: ffffffff8177fd84
RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90000a17f98
RBP: 0000000000000000 R08: ffffc90000a17fa7 R09: 1ffff92000142ff4
R10: dffffc0000000000 R11: fffff52000142ff5 R12: 0000000000000002
R13: ffffffff91a188de R14: fffff52000142ff5 R15: 1ffff92000142ff3
FS: 0000000000000000(0000) GS:ffff888124de6000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055558ddb2a78 CR3: 000000007f2d2000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 000000000000000c DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__asan_memset+0x22/0x50 mm/kasan/shadow.c:84
unwind_next_frame+0xd04/0x2550 arch/x86/kernel/unwind_orc.c:621
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
kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
poison_slab_object mm/kasan/common.c:253 [inline]
__kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
kasan_slab_free include/linux/kasan.h:235 [inline]
slab_free_hook mm/slub.c:2748 [inline]
slab_free mm/slub.c:6499 [inline]
kfree+0x1c5/0x650 mm/slub.c:6792
skb_kfree_head net/core/skbuff.c:1083 [inline]
skb_free_head net/core/skbuff.c:1095 [inline]
skb_release_data+0x85e/0xab0 net/core/skbuff.c:1122
skb_release_all net/core/skbuff.c:1197 [inline]
__kfree_skb+0x5d/0x210 net/core/skbuff.c:1211
nft_synproxy_eval_v6+0x36a/0x4e0 net/netfilter/nft_synproxy.c:-1
nft_synproxy_do_eval+0x3d1/0x550 net/netfilter/nft_synproxy.c:145
expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285
nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162
nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619
nf_hook include/linux/netfilter.h:280 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323
ip6_input+0x16a/0x270 net/ipv6/ip6_input.c:545
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6264 [inline]
__netif_receive_skb net/core/dev.c:6377 [inline]
process_backlog+0x795/0x18b0 net/core/dev.c:6728
__napi_poll+0xaa/0x330 net/core/dev.c:7787
napi_poll net/core/dev.c:7850 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8007
handle_softirqs+0x226/0x860 kernel/softirq.c:645
do_softirq+0x77/0xd0 kernel/softirq.c:546
__local_bh_enable_ip+0x100/0x140 kernel/softirq.c:473
local_bh_enable include/linux/bottom_half.h:33 [inline]
__alloc_skb+0x1b1/0x7a0 net/core/skbuff.c:699
alloc_skb include/linux/skbuff.h:1384 [inline]
nsim_dev_trap_skb_build drivers/net/netdevsim/dev.c:744 [inline]
nsim_dev_trap_report drivers/net/netdevsim/dev.c:801 [inline]
nsim_dev_trap_report_work+0x25f/0xb40 drivers/net/netdevsim/dev.c:847
process_one_work kernel/workqueue.c:3387 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3470
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3551
kthread+0x38b/0x480 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