rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P23407/1:b..l
rcu: (detected by 1, t=10502 jiffies, g=290113, q=1201956 ncpus=2)
task:syz-executor state:R running task stack:22320 pid:23407 tgid:23407 ppid:23400 task_flags:0x400140 flags:0x00080000
Call Trace:
context_switch kernel/sched/core.c:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
preempt_schedule_irq+0x4b/0x90 kernel/sched/core.c:7606
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:trace_lock_acquire include/trace/events/lock.h:23 [inline]
RIP: 0010:lock_acquire+0x51/0x350 kernel/locking/lockdep.c:5905
Code: 8b 05 2b 3a f2 11 48 89 44 24 50 0f 1f 44 00 00 65 8b 05 2a 3a f2 11 83 f8 08 0f 83 9b 01 00 00 89 c0 48 0f a3 05 57 1c d7 0e <73> 0d e8 f8 34 09 00 84 c0 0f 84 e2 01 00 00 83 3d 49 4d d7 0e 00
RSP: 0018:ffffc90004267050 EFLAGS: 00000297
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 0000000000000002
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffff8ed5c8a0
RBP: 1ffff9200084ce44 R08: 0000000000000000 R09: 0000000000000000
R10: ffffc90004267238 R11: fffff5200084ce49 R12: ffffffff8ed5c8a0
R13: 0000000000000002 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
__unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
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_frozen_pages+0xc93/0xd90 mm/page_alloc.c:2962
__slab_free+0x274/0x2c0 mm/slub.c:5823
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_kmalloc+0x22/0xb0 mm/kasan/common.c:417
kasan_kmalloc include/linux/kasan.h:263 [inline]
__do_kmalloc_node mm/slub.c:5414 [inline]
__kmalloc_noprof+0x36b/0x720 mm/slub.c:5439
_kmalloc_noprof include/linux/slab.h:995 [inline]
_kzalloc_noprof include/linux/slab.h:1312 [inline]
tomoyo_encode2 security/tomoyo/realpath.c:45 [inline]
tomoyo_encode+0x2ad/0x570 security/tomoyo/realpath.c:80
tomoyo_realpath_from_path+0x5fa/0x640 security/tomoyo/realpath.c:283
tomoyo_get_realpath security/tomoyo/file.c:151 [inline]
tomoyo_check_open_permission+0x229/0x470 security/tomoyo/file.c:776
security_file_open+0xa9/0x240 security/security.c:2739
do_dentry_open+0x4a0/0x1380 fs/open.c:973
vfs_open+0x3b/0x340 fs/open.c:1101
do_open fs/namei.c:4837 [inline]
path_openat+0x1443/0x1d60 fs/namei.c:5000
do_file_open+0x23e/0x4a0 fs/namei.c:5029
do_sys_openat2+0x115/0x200 fs/open.c:1417
do_sys_open fs/open.c:1423 [inline]
__do_sys_openat fs/open.c:1439 [inline]
__se_sys_openat fs/open.c:1434 [inline]
__x64_sys_openat+0x138/0x170 fs/open.c:1434
do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb7a4d9d47c
RSP: 002b:00007fb7a514ec50 EFLAGS: 00000206 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007fb7a4e344bb RCX: 00007fb7a4d9d47c
RDX: 0000000000090800 RSI: 00007fb7a514fe00 RDI: 00000000ffffff9c
RBP: 00007fb7a514fdec R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 00007fb7a514fe00
R13: 00007fb7a4e344bb R14: 0000000000170920 R15: 00007fb7a514fe40
rcu: rcu_preempt kthread starved for 6169 jiffies! g290113 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:5533 [inline]
__schedule+0x17db/0x58f0 kernel/sched/core.c:7284
__schedule_loop kernel/sched/core.c:7361 [inline]
schedule+0x164/0x2b0 kernel/sched/core.c:7376
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:
Sending NMI from CPU 1 to CPUs 0:
NMI backtrace for cpu 0
CPU: 0 UID: 0 PID: 3227 Comm: kworker/R-bat_e 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: bat_events batadv_dat_purge
RIP: 0010:on_stack arch/x86/include/asm/stacktrace.h:58 [inline]
RIP: 0010:stack_access_ok arch/x86/kernel/unwind_orc.c:409 [inline]
RIP: 0010:deref_stack_reg arch/x86/kernel/unwind_orc.c:419 [inline]
RIP: 0010:unwind_next_frame+0xb9f/0x2550 arch/x86/kernel/unwind_orc.c:614
Code: 6e 10 48 b8 00 00 00 00 00 fc ff df 48 8b 4c 24 10 0f b6 04 01 84 c0 0f 85 3b 14 00 00 41 83 3e 00 0f 95 c0 49 39 d7 0f 96 c1 <20> c1 49 39 d5 0f 97 c0 20 c8 3c 01 75 18 48 8d 42 08 4c 39 f8 0f
RSP: 0018:ffffc900000069a8 EFLAGS: 00000293
RAX: 0000000000000001 RBX: 1ffff92000000d56 RCX: 1ffff92000000d01
RDX: ffffc90000006b38 RSI: 0000000000000002 RDI: ffffc90000006ab8
RBP: 1ffffffff22228f9 R08: ffffc90000006b40 R09: 0000000000000000
R10: ffffc90000006af8 R11: fffff52000000d61 R12: 1ffff92000000d57
R13: ffffc90000008000 R14: ffffc90000006aa8 R15: ffffc90000000000
FS: 0000000000000000(0000) GS:ffff888124cc8000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f593b94eccc CR3: 0000000062f7a000 CR4: 00000000003526f0
DR0: ffffffffffffffff DR1: 00000000000001f8 DR2: 0000000000000002
DR3: ffffffffefffff15 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
__unwind_start+0x514/0x660 arch/x86/kernel/unwind_orc.c:787
unwind_start arch/x86/include/asm/unwind.h:64 [inline]
arch_stack_walk+0xe3/0x150 arch/x86/kernel/stacktrace.c:24
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:351 [inline]
__kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:377
kasan_slab_alloc include/linux/kasan.h:253 [inline]
slab_post_alloc_hook mm/slub.c:4683 [inline]
slab_alloc_node mm/slub.c:4996 [inline]
kmem_cache_alloc_noprof+0x2b9/0x600 mm/slub.c:5010
dst_alloc+0x105/0x170 net/core/dst.c:90
rt_dst_alloc net/ipv4/route.c:1681 [inline]
__mkroute_output net/ipv4/route.c:2684 [inline]
ip_route_output_key_hash_rcu+0x14ac/0x2720 net/ipv4/route.c:2904
ip_route_output_key_hash+0x18d/0x2a0 net/ipv4/route.c:2734
__ip_route_output_key include/net/route.h:169 [inline]
ip_route_output_flow+0x2a/0x150 net/ipv4/route.c:2961
ip_route_output_key include/net/route.h:179 [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_ipv4+0x195/0x290 net/netfilter/nft_chain_filter.c:24
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
NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:325
__netif_receive_skb_one_core net/core/dev.c:6265 [inline]
__netif_receive_skb net/core/dev.c:6378 [inline]
process_backlog+0xa6b/0x18b0 net/core/dev.c:6729
__napi_poll+0xaa/0x330 net/core/dev.c:7798
napi_poll net/core/dev.c:7861 [inline]
net_rx_action+0x61d/0xf50 net/core/dev.c:8018
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
spin_unlock_bh include/linux/spinlock.h:407 [inline]
__batadv_dat_purge net/batman-adv/distributed-arp-table.c:252 [inline]
batadv_dat_purge+0x2d7/0x3c0 net/batman-adv/distributed-arp-table.c:271
process_one_work kernel/workqueue.c:3396 [inline]
process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3479
rescuer_thread+0x7c5/0x10e0 kernel/workqueue.c:3703
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