rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5635/1:b..l..
rcu: (detected by 1, t=10503 jiffies, g=27221, q=1080166 ncpus=2)
task:syz-executor state:R running task stack:20904 pid:5635 tgid:5635 ppid:1 task_flags:0x40054c flags:0x00080003
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7662
irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:543 [inline]
irqentry_exit+0x14f/0x9b0 kernel/entry/common.c:154
asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:page_ext_invalid mm/page_ext.c:244 [inline]
RIP: 0010:lookup_page_ext mm/page_ext.c:260 [inline]
RIP: 0010:page_ext_get+0x1c8/0x2e0 mm/page_ext.c:523
Code: 74 08 4c 89 ff e8 38 0e f4 ff 4d 8b 3f e8 e0 32 60 ff 89 c5 31 ff 89 c6 e8 f5 f2 7c ff 85 ed 0f 84 f4 00 00 00 e8 d8 ed 7c ff <4d> 85 ff 40 0f 95 c5 4c 89 fe 48 83 e6 01 41 0f 94 c4 31 ff e8 8f
RSP: 0018:ffffc90003a87770 EFLAGS: 00000293
RAX: ffffffff824c5678 RBX: ffffffff824c54d2 RCX: ffff88807eb81f40
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000
RBP: 0000000000000001 R08: ffffffff824c54d2 R09: 0000000000000000
R10: dffffc0000000000 R11: fffff940002f2b77 R12: 0000000000000160
R13: dffffc0000000000 R14: 000000000005e56e R15: ffff88801d880000
__reset_page_owner+0x29/0x2a0 mm/page_owner.c:324
reset_page_owner include/linux/page_owner.h:26 [inline]
__free_pages_prepare mm/page_alloc.c:1403 [inline]
free_pages_prepare+0x9eb/0xaf0 mm/page_alloc.c:1448
__free_contig_range_common+0x174/0x340 mm/page_alloc.c:7065
__free_contig_range mm/page_alloc.c:7110 [inline]
free_pages_bulk+0x48/0x120 mm/page_alloc.c:5333
vm_area_free_pages mm/vmalloc.c:3517 [inline]
vfree+0x22c/0x490 mm/vmalloc.c:3566
kcov_put kernel/kcov.c:469 [inline]
kcov_close+0x28/0x50 kernel/kcov.c:574
__fput+0x408/0xa40 fs/file_table.c:513
fput_close_sync+0x11f/0x240 fs/file_table.c:619
filp_close_sync+0x6e/0xa0 fs/open.c:1897
close_files fs/file.c:572 [inline]
put_files_struct+0x230/0x3c0 fs/file.c:584
do_exit+0x6f0/0x2360 kernel/exit.c:977
do_group_exit+0x22d/0x2f0 kernel/exit.c:1123
get_signal+0x136a/0x1430 kernel/signal.c:3113
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:343 [inline]
do_syscall_64+0x328/0x520 arch/x86/entry/syscall_64.c:89
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f2d4799e15a
RSP: 002b:00007ffea62ba118 EFLAGS: 00000286 ORIG_RAX: 0000000000000106
RAX: 0000000000000000 RBX: 00007f2d47a36fb3 RCX: 00007f2d4799e15a
RDX: 00007ffea62ba140 RSI: 00007ffea62ba1d0 RDI: 00000000ffffff9c
RBP: 00007ffea62ba1d0 R08: 00007ffea62bb1d0 R09: 00000000ffffffff
R10: 0000000000000100 R11: 0000000000000286 R12: 00007ffea62bb260
R13: 00007f2d47a36fb3 R14: 000000000002a4ec R15: 00007ffea62bb2a0
rcu: rcu_preempt kthread starved for 662 jiffies! g27221 f0x2 RCU_GP_WAIT_FQS(5) ->state=R ->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:27496 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5583 [inline]
__schedule+0x17dd/0x5830 kernel/sched/core.c:7382
__schedule_loop kernel/sched/core.c:7459 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7474
schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99
rcu_gp_fqs_loop+0x30c/0x1230 kernel/rcu/tree.c:2122
rcu_gp_kthread+0x9c/0x340 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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 6482 Comm: kworker/u8:19 Not tainted syzkaller #0 PREEMPT(full)
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/07/2026
Workqueue: events_unbound nsim_dev_trap_report_work
RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline]
RIP: 0010:lock_release+0x268/0x3c0 kernel/locking/lockdep.c:5966
Code: 89 c5 7f d0 4c 89 ff 4c 89 f6 48 8b 54 24 18 e8 6e 31 00 00 48 8b 5c 24 08 48 c7 c7 24 ab a7 8e e8 ad b7 74 0a b8 ff ff ff ff <65> 0f c1 05 38 6a 46 13 83 f8 01 75 2e 9c 58 a9 00 02 00 00 75 42
RSP: 0018:ffffc900000067d8 EFLAGS: 00000002
RAX: 00000000ffffffff RBX: 0000000000000206 RCX: 0000000000000102
RDX: ffffc90000006901 RSI: ffffffff8ea7ab24 RDI: ffffffff8c8ff980
RBP: ffff888075d5ea88 R08: ffffc900000070b0 R09: 0000000000000000
R10: ffffc90000006938 R11: fffff52000000d29 R12: 0000000000000007
R13: 0000000000000007 R14: ffffffff9015a420 R15: ffff888075d5ddc0
FS: 0000000000000000(0000) GS:ffff888123376000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff30ae62b0c CR3: 000000007f20a000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000002157
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
rcu_lock_release include/linux/rcupdate.h:319 [inline]
rcu_read_unlock include/linux/rcupdate.h:880 [inline]
class_rcu_destructor include/linux/rcupdate.h:1216 [inline]
unwind_next_frame+0x1baa/0x2550 arch/x86/kernel/unwind_orc.c:709
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
poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
__kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
kasan_kmalloc include/linux/kasan.h:263 [inline]
__kmalloc_cache_noprof+0x31c/0x600 mm/slub.c:5680
_kmalloc_noprof include/linux/slab.h:991 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
ref_tracker_alloc+0x221/0x530 lib/ref_tracker.c:270
__netdev_tracker_alloc include/linux/netdevice.h:4554 [inline]
netdev_hold include/linux/netdevice.h:4583 [inline]
dst_init+0xbe/0x470 net/core/dst.c:52
dst_alloc+0x12a/0x170 net/core/dst.c:94
rt_dst_alloc net/ipv4/route.c:1690 [inline]
__mkroute_output net/ipv4/route.c:2693 [inline]
ip_route_output_key_hash_rcu+0x14ac/0x2720 net/ipv4/route.c:2913
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2743
__ip_route_output_key include/net/route.h:175 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2970
ip_route_output_key include/net/route.h:185 [inline]
ip_route_me_harder+0x762/0xfe0 net/ipv4/netfilter.c:54
synproxy_send_tcp+0x332/0x670 net/netfilter/nf_synproxy_core.c:434
synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487
nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59
nft_synproxy_do_eval+0x389/0x5d0 net/netfilter/nft_synproxy.c:142
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:633
nf_hook include/linux/netfilter.h:280 [inline]
NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:323
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6433 [inline]
__netif_receive_skb net/core/dev.c:6546 [inline]
process_backlog+0xa6b/0x18b0 net/core/dev.c:6897
__napi_poll+0xaa/0x330 net/core/dev.c:7966
napi_poll net/core/dev.c:8029 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8186
handle_softirqs+0x265/0x8d0 kernel/softirq.c:669
do_softirq+0x77/0xd0 kernel/softirq.c:569
__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:700
alloc_skb include/linux/skbuff.h:1390 [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/0xb30 drivers/net/netdevsim/dev.c:847
process_one_work kernel/workqueue.c:3495 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
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