rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P6083/1:b..l
rcu: 	(detected by 0, t=10502 jiffies, g=94641, q=958 ncpus=1)
task:syz-executor    state:R  running task     stack:23544 pid:6083  tgid:6083  ppid:6068   task_flags:0x400140 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7284
 preempt_schedule_irq+0x4e/0x90 kernel/sched/core.c:7606
 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline]
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline]
 irqentry_exit+0x205/0xa10 kernel/entry/common.c:167
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_release+0x19e/0x310 kernel/locking/lockdep.c:5968
Code: ff 65 0f c1 05 db bd a5 12 83 f8 01 0f 85 27 01 00 00 9c 58 f6 c4 02 0f 85 12 01 00 00 41 f7 c6 00 02 00 00 0f 85 c8 00 00 00 <48> 8b 44 24 10 65 48 2b 05 dd 76 a5 12 0f 85 4d 01 00 00 48 83 c4
RSP: 0018:ffffc9000549ef78 EFLAGS: 00000206
RAX: 0000000000000046 RBX: ffffffff8edec4e0 RCX: ffffc9000549ef84
RDX: 0000000000000000 RSI: ffffffff8e366d33 RDI: ffffffff8c623580
RBP: ffffffff81b9a54e R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 0000000000018a1f R12: ffff88802fb78000
R13: ffffc9000549f030 R14: 0000000000000202 R15: 0000000000000005
 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+0x3c3/0x2090 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
 save_stack+0x162/0x1e0 mm/page_owner.c:183
 __reset_page_owner+0x84/0x190 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+0x79f/0x10f0 mm/page_alloc.c:2962
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 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+0x269/0x6a0 mm/slub.c:5010
 ptlock_alloc+0x1f/0x70 mm/memory.c:7721
 ptlock_init include/linux/mm.h:3884 [inline]
 pagetable_pte_ctor include/linux/mm.h:3933 [inline]
 __pte_alloc_one_noprof include/asm-generic/pgalloc.h:79 [inline]
 pte_alloc_one+0x82/0x3d0 arch/x86/mm/pgtable.c:18
 __pte_alloc+0x6d/0x380 mm/memory.c:453
 copy_pte_range mm/memory.c:1335 [inline]
 copy_pmd_range mm/memory.c:1490 [inline]
 copy_pud_range mm/memory.c:1527 [inline]
 copy_p4d_range mm/memory.c:1551 [inline]
 copy_page_range+0x3b36/0x57c0 mm/memory.c:1637
 dup_mmap+0x1230/0x2370 mm/mmap.c:1819
 dup_mm kernel/fork.c:1543 [inline]
 copy_mm kernel/fork.c:1595 [inline]
 copy_process+0x4811/0x8370 kernel/fork.c:2310
 kernel_clone+0x176/0x9d0 kernel/fork.c:2769
 __do_sys_clone+0xd9/0x120 kernel/fork.c:2911
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x123/0x790 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f98cd1c6bd2
RSP: 002b:00007fffb7686d00 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fffb7686d00 RCX: 00007f98cd1c6bd2
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00007fffb7686e8c R08: 0000000000000000 R09: 0000000000000001
R10: 00005555873b47d0 R11: 0000000000000246 R12: 0000000000000001
R13: 00000000000927c0 R14: 0000000000055524 R15: 00007fffb7686ee0
 </TASK>
rcu: rcu_preempt kthread starved for 3290 jiffies! g94641 f0x0 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:27560 pid:17    tgid:17    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5533 [inline]
 __schedule+0x1259/0x6920 kernel/sched/core.c:7284
 __schedule_loop kernel/sched/core.c:7361 [inline]
 schedule+0xdd/0x2c0 kernel/sched/core.c:7376
 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1a9/0x8f0 kernel/rcu/tree.c:2122
 rcu_gp_kthread+0x17a/0x220 kernel/rcu/tree.c:2330
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 3222 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 08/26/2026
Workqueue: bat_events batadv_dat_purge
RIP: 0010:arch_stack_walk+0x7f/0xf0 arch/x86/kernel/stacktrace.c:27
Code: 2e 2e 41 ff d4 84 c0 74 50 49 8b 8e 98 00 00 00 4c 89 f2 4c 89 fe 48 89 df e8 ed 18 09 00 8b 95 70 ff ff ff 85 d2 75 21 eb 2f <4c> 89 ef 2e e8 cc 69 4f 1e 84 c0 74 22 48 89 df e8 2c f8 08 00 8b
RSP: 0018:ffffc900000071d8 EFLAGS: 00000282
RAX: ffffffff8a790c76 RBX: ffffc900000071d8 RCX: ffffc9000000712c
RDX: 1ffff92000000e44 RSI: ffffffff8a790c76 RDI: ffffffff8a790c76
RBP: ffffc90000007268 R08: 0000000000000001 R09: 0000000000000007
R10: 0000000000000200 R11: 000000000008ea39 R12: ffffffff81f5ef20
R13: ffffc90000007298 R14: 0000000000000000 R15: ffff888024704b00
FS:  0000000000000000(0000) GS:ffff888123b53000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ff8deded158 CR3: 000000005b947000 CR4: 00000000003526f0
Call Trace:
 <IRQ>
 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
 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5f/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:6508 [inline]
 kmem_cache_free+0x127/0x6c0 mm/slub.c:6635
 kfree_skbmem+0x19a/0x210 net/core/skbuff.c:1145
 __kfree_skb net/core/skbuff.c:1212 [inline]
 consume_skb net/core/skbuff.c:1448 [inline]
 consume_skb+0xd1/0x110 net/core/skbuff.c:1442
 nft_synproxy_eval_v6 net/netfilter/nft_synproxy.c:91 [inline]
 nft_synproxy_do_eval+0x919/0xce0 net/netfilter/nft_synproxy.c:145
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x2e5/0x19d0 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0xf3/0x400 net/netfilter/nft_chain_filter.c:162
 nf_hook_entry_hookfn include/linux/netfilter.h:165 [inline]
 nf_hook_slow+0xbf/0x220 net/netfilter/core.c:619
 nf_hook.constprop.0+0x2a6/0x750 include/linux/netfilter.h:280
 NF_HOOK include/linux/netfilter.h:323 [inline]
 ip6_input+0xe0/0x2f0 net/ipv6/ip6_input.c:545
 dst_input include/net/dst.h:480 [inline]
 ip6_rcv_finish net/ipv6/ip6_input.c:119 [inline]
 NF_HOOK include/linux/netfilter.h:325 [inline]
 NF_HOOK include/linux/netfilter.h:319 [inline]
 ipv6_rcv+0x263/0x3d0 net/ipv6/ip6_input.c:351
 __netif_receive_skb_one_core+0x12d/0x1e0 net/core/dev.c:6264
 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6377
 process_backlog+0x487/0x1600 net/core/dev.c:6728
 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7787
 napi_poll net/core/dev.c:7850 [inline]
 net_rx_action+0xa40/0xf20 net/core/dev.c:8007
 handle_softirqs+0x1e6/0x9d0 kernel/softirq.c:645
 do_softirq kernel/softirq.c:546 [inline]
 do_softirq+0xaf/0xf0 kernel/softirq.c:533
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0xff/0x120 kernel/softirq.c:473
 spin_unlock_bh include/linux/spinlock.h:407 [inline]
 __batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:252
 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:233 [inline]
 batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:271
 process_one_work+0xac7/0x1b10 kernel/workqueue.c:3396
 process_scheduled_works kernel/workqueue.c:3479 [inline]
 rescuer_thread+0x918/0x14e0 kernel/workqueue.c:3703
 kthread+0x373/0x450 kernel/kthread.c:436
 ret_from_fork+0x730/0xd60 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>