rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7615/1:b..l P5201/1:b..l
rcu: 	(detected by 0, t=10503 jiffies, g=27317, q=756595 ncpus=2)
task:klogd           state:R  running task     stack:22632 pid:5201  tgid:5201  ppid:1      task_flags:0x400100 flags:0x00000002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b88/0x5240 kernel/sched/core.c:6767
 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090
 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_acquire+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1
Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e
RSP: 0018:ffffc900030c7028 EFLAGS: 00000206
RAX: eb3ac36d315ab500 RBX: ffffffff8ed3dfe0 RCX: eb3ac36d315ab500
RDX: 0000000000000000 RSI: ffffffff8e4fd53d RDI: ffffffff8ca1b6a0
RBP: ffffffff9368a020 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:331 [inline]
 rcu_read_lock include/linux/rcupdate.h:841 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xd5/0x23b0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfc/0x1f0 mm/page_owner.c:156
 __reset_page_owner+0x76/0x1e0 mm/page_owner.c:308
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0xde8/0x10a0 mm/page_alloc.c:2680
 discard_slab mm/slub.c:2720 [inline]
 __put_partials+0x160/0x1c0 mm/slub.c:3189
 put_cpu_partial+0x17e/0x250 mm/slub.c:3264
 __slab_free+0x294/0x390 mm/slub.c:4516
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286
 __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:385
 kasan_kmalloc include/linux/kasan.h:260 [inline]
 __do_kmalloc_node mm/slub.c:4331 [inline]
 __kmalloc_node_track_caller_noprof+0x295/0x4d0 mm/slub.c:4350
 kmalloc_reserve+0x111/0x2a0 net/core/skbuff.c:599
 __alloc_skb+0x1f2/0x480 net/core/skbuff.c:668
 alloc_skb include/linux/skbuff.h:1340 [inline]
 alloc_skb_with_frags+0xc3/0x830 net/core/skbuff.c:6639
 sock_alloc_send_pskb+0x91c/0xa70 net/core/sock.c:2949
 unix_dgram_sendmsg+0x6d4/0x1ea0 net/unix/af_unix.c:2007
 sock_sendmsg_nosec net/socket.c:712 [inline]
 __sock_sendmsg+0x221/0x270 net/socket.c:727
 __sys_sendto+0x365/0x4c0 net/socket.c:2180
 __do_sys_sendto net/socket.c:2187 [inline]
 __se_sys_sendto net/socket.c:2183 [inline]
 __x64_sys_sendto+0xde/0x100 net/socket.c:2183
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f443f37c9b5
RSP: 002b:00007ffebd86d008 EFLAGS: 00000246 ORIG_RAX: 000000000000002c
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f443f37c9b5
RDX: 000000000000005f RSI: 00005599b74ad1d0 RDI: 0000000000000003
RBP: 00005599b74a6910 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000004000 R11: 0000000000000246 R12: 0000000000000013
R13: 00007f443f50a212 R14: 00007ffebd86d108 R15: 0000000000000000
 </TASK>
task:syz-executor    state:R  running task     stack:23624 pid:7615  tgid:7615  ppid:5829   task_flags:0x400000 flags:0x00004002
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b88/0x5240 kernel/sched/core.c:6767
 preempt_schedule_notrace+0x103/0x140 kernel/sched/core.c:7040
 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13
 rcu_is_watching+0x7e/0xb0 kernel/rcu/tree.c:737
 rcu_read_lock include/linux/rcupdate.h:842 [inline]
 class_rcu_constructor include/linux/rcupdate.h:1155 [inline]
 unwind_next_frame+0xe7/0x23b0 arch/x86/kernel/unwind_orc.c:479
 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25
 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122
 save_stack+0xfc/0x1f0 mm/page_owner.c:156
 __set_page_owner+0x93/0x530 mm/page_owner.c:329
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717
 prep_new_page mm/page_alloc.c:1725 [inline]
 get_page_from_freelist+0x352b/0x36c0 mm/page_alloc.c:3652
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301
 alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline]
 alloc_pages_noprof+0x121/0x190 mm/mempolicy.c:2392
 get_free_pages_noprof+0xc/0x30 mm/page_alloc.c:4993
 kasan_populate_vmalloc_pte+0x38/0xe0 mm/kasan/shadow.c:304
 apply_to_pte_range mm/memory.c:2941 [inline]
 apply_to_pmd_range mm/memory.c:2985 [inline]
 apply_to_pud_range mm/memory.c:3021 [inline]
 apply_to_p4d_range mm/memory.c:3057 [inline]
 __apply_to_page_range+0x808/0xde0 mm/memory.c:3093
 alloc_vmap_area+0x1d48/0x2410 mm/vmalloc.c:2035
 __get_vm_area_node+0x1c8/0x2d0 mm/vmalloc.c:3137
 __vmalloc_node_range_noprof+0x349/0x1390 mm/vmalloc.c:3804
 vmalloc_user_noprof+0x74/0x80 mm/vmalloc.c:3996
 kcov_ioctl+0x56/0x640 kernel/kcov.c:716
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:906 [inline]
 __se_sys_ioctl+0xf1/0x160 fs/ioctl.c:892
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f6371d8cd6b
RSP: 002b:00007ffc18325380 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007f6371d8cd6b
RDX: 0000000000100000 RSI: ffffffff80086301 RDI: 00000000000000d7
RBP: 00007f6371fa5f40 R08: 00000000000000da R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001
R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000
 </TASK>
rcu: rcu_preempt kthread starved for 9705 jiffies! g27317 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:26976 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00004000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5382 [inline]
 __schedule+0x1b88/0x5240 kernel/sched/core.c:6767
 __schedule_loop kernel/sched/core.c:6845 [inline]
 schedule+0x163/0x360 kernel/sched/core.c:6860
 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046
 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 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 6.15.0-rc1-syzkaller-00025-gbec7dcbc242c #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xd9/0x140 kernel/locking/spinlock.c:194
Code: 9c 8f 44 24 20 42 80 3c 2b 00 74 08 4c 89 f7 e8 3d 3b fa f5 f6 44 24 21 02 75 55 41 f7 c7 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> a2 48 5d f5 65 8b 05 cb 5d 35 07 85 c0 74 46 48 c7 04 24 0e 36
RSP: 0018:ffffc90000006d80 EFLAGS: 00000206
RAX: 8d59e97badad6c00 RBX: 1ffff92000000db4 RCX: ffffffff81cb469c
RDX: 0000000000000000 RSI: ffffffff8e69c6c2 RDI: 0000000000000001
RBP: ffffc90000006e10 R08: ffffffff905fe077 R09: 1ffffffff20bfc0e
R10: dffffc0000000000 R11: fffffbfff20bfc0f R12: 1ffff92000000db0
R13: dffffc0000000000 R14: ffffc90000006da0 R15: 0000000000000246
FS:  0000000000000000(0000) GS:ffff888124f96000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000244000 CR3: 000000007ef74000 CR4: 00000000003526f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 debug_object_active_state+0x240/0x370 lib/debugobjects.c:1055
 debug_rcu_head_queue kernel/rcu/rcu.h:225 [inline]
 __call_rcu_common kernel/rcu/tree.c:3067 [inline]
 call_rcu+0xb7/0xad0 kernel/rcu/tree.c:3202
 refdst_drop include/net/dst.h:263 [inline]
 skb_dst_drop include/net/dst.h:275 [inline]
 skb_release_head_state+0x73/0x250 net/core/skbuff.c:1146
 skb_release_all net/core/skbuff.c:1160 [inline]
 __kfree_skb net/core/skbuff.c:1176 [inline]
 consume_skb+0x60/0xf0 net/core/skbuff.c:1408
 nft_synproxy_eval_v4+0x3d4/0x610 net/netfilter/nft_synproxy.c:60
 nft_synproxy_do_eval+0x36a/0xa90 net/netfilter/nft_synproxy.c:141
 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline]
 nft_do_chain+0x4b2/0x1db0 net/netfilter/nf_tables_core.c:285
 nft_do_chain_inet+0x41f/0x6b0 net/netfilter/nft_chain_filter.c:161
 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline]
 nf_hook_slow+0xc8/0x220 net/netfilter/core.c:626
 nf_hook include/linux/netfilter.h:269 [inline]
 NF_HOOK+0x29b/0x450 include/linux/netfilter.h:312
 NF_HOOK+0x3a0/0x450 include/linux/netfilter.h:314
 __netif_receive_skb_one_core net/core/dev.c:5894 [inline]
 __netif_receive_skb+0x2c9/0x670 net/core/dev.c:6007
 process_backlog+0x664/0x15c0 net/core/dev.c:6359
 __napi_poll+0xcb/0x480 net/core/dev.c:7331
 napi_poll net/core/dev.c:7395 [inline]
 net_rx_action+0x89d/0x1240 net/core/dev.c:7517
 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579
 __do_softirq kernel/softirq.c:613 [inline]
 invoke_softirq kernel/softirq.c:453 [inline]
 __irq_exit_rcu+0xfb/0x220 kernel/softirq.c:680
 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline]
 sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81
Code: 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 13 a1 17 00 f3 0f 1e fa fb f4 <c3> cc cc cc cc 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90
RSP: 0018:ffffffff8ea07d60 EFLAGS: 000002c6
RAX: 8d59e97badad6c00 RBX: ffffffff8197af7e RCX: ffffffff8c30995c
RDX: 0000000000000001 RSI: ffffffff8e69c6c2 RDI: ffffffff8ca1b6a0
RBP: ffffffff8ea07eb8 R08: ffff8880b8632b5b R09: 1ffff110170c656b
R10: dffffc0000000000 R11: ffffed10170c656c R12: 1ffffffff1d40fc6
R13: 1ffffffff1d52cb0 R14: 0000000000000000 R15: dffffc0000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline]
 default_idle+0x13/0x20 arch/x86/kernel/process.c:748
 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117
 cpuidle_idle_call kernel/sched/idle.c:185 [inline]
 do_idle+0x22e/0x5d0 kernel/sched/idle.c:325
 cpu_startup_entry+0x42/0x60 kernel/sched/idle.c:423
 rest_init+0x2dc/0x300 init/main.c:743
 start_kernel+0x484/0x510 init/main.c:1099
 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513
 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494
 common_startup_64+0x13e/0x147
 </TASK>