rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P18161/1:b..l P18157/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=79897, q=3061469 ncpus=2)
task:syz.1.3239      state:R  running task     stack:27624 pid:18157 tgid:18153 ppid:16989  task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7145
 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12
 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186
 spin_unlock include/linux/spinlock.h:391 [inline]
 wp_page_copy mm/memory.c:3653 [inline]
 do_wp_page+0x177b/0x4f00 mm/memory.c:4013
 handle_pte_fault mm/memory.c:6068 [inline]
 __handle_mm_fault+0x1b2d/0x2a50 mm/memory.c:6195
 handle_mm_fault+0x589/0xd10 mm/memory.c:6364
 do_user_addr_fault+0x7a6/0x1370 arch/x86/mm/fault.c:1387
 handle_page_fault arch/x86/mm/fault.c:1476 [inline]
 exc_page_fault+0x5c/0xb0 arch/x86/mm/fault.c:1532
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0010:__put_user_nocheck_4+0x3/0x10 arch/x86/lib/putuser.S:104
Code: d9 0f 01 cb 89 01 31 c9 0f 01 ca e9 07 69 03 00 0f 1f 80 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 01 cb <89> 01 31 c9 0f 01 ca c3 cc cc cc cc 90 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc900033979f8 EFLAGS: 00050246
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000200000061030
RDX: 0000000000080000 RSI: ffffffff89630863 RDI: 0000000000000005
RBP: ffffc90003397d98 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000
R13: 0000200000061000 R14: ffffc90003397ddc R15: 0000000000000002
 ____sys_recvmsg+0x2ee/0x6b0 net/socket.c:2847
 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2876
 do_recvmmsg+0x2fe/0x750 net/socket.c:2971
 __sys_recvmmsg net/socket.c:3045 [inline]
 __do_sys_recvmmsg net/socket.c:3068 [inline]
 __se_sys_recvmmsg net/socket.c:3061 [inline]
 __x64_sys_recvmmsg+0x22a/0x280 net/socket.c:3061
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f37fa18ebe9
RSP: 002b:00007f37faf58038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b
RAX: ffffffffffffffda RBX: 00007f37fa3b6090 RCX: 00007f37fa18ebe9
RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004
RBP: 00007f37fa211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f37fa3b6128 R14: 00007f37fa3b6090 R15: 00007ffdd5b3c348
 </TASK>
task:syz.1.3239      state:R  running task     stack:28376 pid:18161 tgid:18153 ppid:16989  task_flags:0x400040 flags:0x00004006
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7288
 irqentry_exit+0x36/0x90 kernel/entry/common.c:197
 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707
RIP: 0010:unwind_next_frame+0x154b/0x20a0 arch/x86/kernel/unwind_orc.c:648
Code: 89 e2 48 89 c5 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df 80 3c 02 00 0f 84 84 fa ff ff 4c 89 e7 e8 0a ef b6 00 e9 77 fa ff ff <48> ba 00 00 00 00 00 fc ff df 48 8d 79 02 48 89 f8 48 c1 e8 03 0f
RSP: 0018:ffffc900042d73e0 EFLAGS: 00000246
RAX: 0000000000000001 RBX: 0000000000000001 RCX: ffffffff915011d6
RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffffc900042d7498 R08: ffffffff915011da R09: 0000000000000000
R10: ffffc900042d7450 R11: 0000000000012be3 R12: ffffc900042d74a0
R13: ffffc900042d7450 R14: ffffc900042d7690 R15: ffffc900042d7484
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 save_stack+0x160/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x84/0x1a0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 discard_slab mm/slub.c:2753 [inline]
 __put_partials+0x165/0x1c0 mm/slub.c:3218
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x8a/0xb0 mm/kasan/common.c:396
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4365 [inline]
 __kmalloc_node_track_caller_noprof+0x221/0x510 mm/slub.c:4384
 __kmemdup_nul mm/util.c:64 [inline]
 kstrdup+0x53/0x100 mm/util.c:84
 kstrdup_const+0x63/0x80 mm/util.c:104
 __kernfs_new_node+0x9b/0x8e0 fs/kernfs/dir.c:633
 kernfs_new_node+0x13c/0x1e0 fs/kernfs/dir.c:713
 __kernfs_create_file+0x53/0x350 fs/kernfs/file.c:1039
 cgroup_add_file kernel/cgroup/cgroup.c:4297 [inline]
 cgroup_addrm_files+0x546/0xc20 kernel/cgroup/cgroup.c:4351
 css_populate_dir+0x169/0x580 kernel/cgroup/cgroup.c:1785
 cgroup_apply_control_enable+0x3f3/0xbb0 kernel/cgroup/cgroup.c:3297
 cgroup_mkdir+0x5e7/0x11f0 kernel/cgroup/cgroup.c:5893
 kernfs_iop_mkdir+0x111/0x190 fs/kernfs/dir.c:1268
 vfs_mkdir+0x590/0x8c0 fs/namei.c:4366
 do_mkdirat+0x304/0x3e0 fs/namei.c:4399
 __do_sys_mkdir fs/namei.c:4421 [inline]
 __se_sys_mkdir fs/namei.c:4419 [inline]
 __x64_sys_mkdir+0xef/0x140 fs/namei.c:4419
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4c0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f37fa18ebe9
RSP: 002b:00007f37faf37038 EFLAGS: 00000246 ORIG_RAX: 0000000000000053
RAX: ffffffffffffffda RBX: 00007f37fa3b6180 RCX: 00007f37fa18ebe9
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f37fa211e19 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f37fa3b6218 R14: 00007f37fa3b6180 R15: 00007ffdd5b3c348
 </TASK>
rcu: rcu_preempt kthread starved for 4281 jiffies! g79897 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:26688 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5357 [inline]
 __schedule+0x1190/0x5de0 kernel/sched/core.c:6961
 __schedule_loop kernel/sched/core.c:7043 [inline]
 schedule+0xe7/0x3a0 kernel/sched/core.c:7058
 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2285
 kthread+0x3c2/0x780 kernel/kthread.c:463
 ret_from_fork+0x5d7/0x6f0 arch/x86/kernel/process.c:148
 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: 0 Comm: swapper/0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
RIP: 0010:__read_once_word_nocheck+0x3/0x10 include/asm-generic/rwonce.h:68
Code: e8 82 7e ac 03 e9 c8 fa ff ff 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 48 8b 07 <e9> 48 b6 2b 0a 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffc90000007120 EFLAGS: 00000202
RAX: 0000000000000003 RBX: 0000000000000002 RCX: ffffc90000008000
RDX: ffffc90000007f01 RSI: ffffc90000007ef8 RDI: ffffc90000007ef8
RBP: ffffc90000007ef8 R08: 0000000000000001 R09: 0000000000000000
R10: ffffc90000007198 R11: 00000000000870c8 R12: ffffc900000071e8
R13: ffffc90000007198 R14: ffffc90000007f28 R15: ffffc900000071cc
FS:  0000000000000000(0000) GS:ffff8881246bc000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffe20755ddc CR3: 0000000062935000 CR4: 00000000003526f0
DR0: 0000000000000046 DR1: 0000000000000000 DR2: 00000000000000d0
DR3: 0000000000000820 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 deref_stack_reg arch/x86/kernel/unwind_orc.c:406 [inline]
 unwind_next_frame+0x15d5/0x20a0 arch/x86/kernel/unwind_orc.c:648
 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2417 [inline]
 slab_free mm/slub.c:4680 [inline]
 kmem_cache_free+0x2d1/0x4d0 mm/slub.c:4782
 kfree_skbmem+0x1a4/0x1f0 net/core/skbuff.c:1109
 __kfree_skb net/core/skbuff.c:1166 [inline]
 consume_skb net/core/skbuff.c:1397 [inline]
 consume_skb+0xcc/0x100 net/core/skbuff.c:1391
 nft_synproxy_eval_v4 net/netfilter/nft_synproxy.c:60 [inline]
 nft_synproxy_do_eval+0xa6b/0xd80 net/netfilter/nft_synproxy.c:141
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x2e6/0x1920 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0x18a/0x340 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline]
 nf_hook_slow+0xbe/0x200 net/netfilter/core.c:623
 nf_hook.constprop.0+0x422/0x750 include/linux/netfilter.h:273
 NF_HOOK include/linux/netfilter.h:316 [inline]
 ip_local_deliver+0x169/0x1f0 net/ipv4/ip_input.c:260
 dst_input include/net/dst.h:471 [inline]
 ip_rcv_finish net/ipv4/ip_input.c:454 [inline]
 NF_HOOK include/linux/netfilter.h:318 [inline]
 NF_HOOK include/linux/netfilter.h:312 [inline]
 ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:574
 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:5979
 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6092
 process_backlog+0x442/0x15e0 net/core/dev.c:6444
 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7494
 napi_poll net/core/dev.c:7557 [inline]
 net_rx_action+0xa9f/0xfe0 net/core/dev.c:7684
 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline]
 sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1050
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82
Code: 5c 62 02 c3 cc cc cc cc 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d d3 72 16 00 fb f4 <e9> 4c 09 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90
RSP: 0018:ffffffff8e207e08 EFLAGS: 000002c2
RAX: 00000000030a86a4 RBX: 0000000000000000 RCX: ffffffff8b939c29
RDX: ffffed1017086656 RSI: ffffffff8c162880 RDI: ffffffff81913321
RBP: fffffbfff1c52ef8 R08: 0000000000000000 R09: ffffed1017086655
R10: ffff8880b84332ab R11: 0000000000000001 R12: 0000000000000000
R13: ffffffff8e2977c0 R14: ffffffff90ab4090 R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:757
 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:122
 cpuidle_idle_call kernel/sched/idle.c:190 [inline]
 do_idle+0x391/0x510 kernel/sched/idle.c:330
 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:428
 rest_init+0x16b/0x2b0 init/main.c:744
 start_kernel+0x3ee/0x4d0 init/main.c:1097
 x86_64_start_reservations+0x18/0x30 arch/x86/kernel/head64.c:307
 x86_64_start_kernel+0x130/0x190 arch/x86/kernel/head64.c:288
 common_startup_64+0x13e/0x148
 </TASK>