rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=37313, q=1536714 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 8947 (4295000099-4294991152), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 8948 jiffies! g37313 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:26064 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x17fb/0x4be0 kernel/sched/core.c:6756 __schedule_loop kernel/sched/core.c:6833 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6848 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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: 16 Comm: ksoftirqd/0 Not tainted 6.13.0-rc7-syzkaller-00043-g619f0b6fad52 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 RIP: 0010:__preempt_count_sub arch/x86/include/asm/preempt.h:84 [inline] RIP: 0010:preempt_count_sub+0x5d/0x170 kernel/sched/core.c:5886 Code: 22 65 8b 05 0d 51 96 7e 89 c1 81 e1 ff ff ff 7f 39 d9 7c 27 81 fb fe 00 00 00 77 07 0f b6 c0 85 c0 74 5f 65 8b 05 eb 50 96 7e db 65 01 1d e2 50 96 7e 5b 41 5e c3 cc cc cc cc 90 e8 fc 6a 49 RSP: 0018:ffffc900000075d8 EFLAGS: 00000002 RAX: 0000000000010102 RBX: 0000000000000001 RCX: 0000000000010102 RDX: dffffc0000000000 RSI: ffffc90000150000 RDI: 0000000000000001 RBP: ffffc900000076c0 R08: ffffc90000156ea0 R09: 0000000000000000 R10: ffffc90000007710 R11: fffff52000000ee4 R12: dffffc0000000000 R13: ffffc900000076c0 R14: dffffc0000000000 R15: ffffc90000156eb0 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fbf87148ef8 CR3: 0000000032fda000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0x18e6/0x22d0 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x260/0x680 lib/debugobjects.c:403 debug_objects_fill_pool lib/debugobjects.c:725 [inline] debug_object_activate+0x493/0x580 lib/debugobjects.c:814 debug_hrtimer_activate kernel/time/hrtimer.c:428 [inline] debug_activate kernel/time/hrtimer.c:469 [inline] enqueue_hrtimer+0x30/0x3c0 kernel/time/hrtimer.c:1076 __run_hrtimer kernel/time/hrtimer.c:1756 [inline] __hrtimer_run_queues+0x6cb/0xd30 kernel/time/hrtimer.c:1803 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1865 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x99/0x22d0 Code: eb 48 c1 eb 03 42 0f b6 04 23 84 c0 0f 85 e1 19 00 00 41 8b 45 00 85 c0 0f 84 d7 18 00 00 89 84 24 84 00 00 00 48 89 6c 24 78 <48> 89 8c 24 90 00 00 00 48 89 5c 24 20 bf 01 00 00 00 e8 30 d8 21 RSP: 0018:ffffc90000156670 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 1ffff9200002ace8 RCX: ffffc90000157f58 RDX: dffffc0000000000 RSI: ffffffff8109e67a RDI: ffffc90000156740 RBP: ffffc90000156778 R08: 0000000000000018 R09: ffffc90000156830 R10: ffffc90000156790 R11: ffffffff818b3aa0 R12: dffffc0000000000 R13: ffffc90000156740 R14: ffffffff8109e67a R15: 0000000000000000 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4119 [inline] slab_alloc_node mm/slub.c:4168 [inline] kmem_cache_alloc_noprof+0x1d9/0x380 mm/slub.c:4175 kmem_alloc_batch lib/debugobjects.c:371 [inline] fill_pool+0x260/0x680 lib/debugobjects.c:403 debug_objects_fill_pool lib/debugobjects.c:725 [inline] debug_object_activate+0x493/0x580 lib/debugobjects.c:814 debug_rcu_head_queue kernel/rcu/rcu.h:224 [inline] __call_rcu_common kernel/rcu/tree.c:3071 [inline] call_rcu+0x97/0xa70 kernel/rcu/tree.c:3190 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:1174 skb_release_all net/core/skbuff.c:1188 [inline] __kfree_skb net/core/skbuff.c:1204 [inline] consume_skb+0x60/0xf0 net/core/skbuff.c:1436 nft_synproxy_eval_v4+0x3d2/0x610 net/netfilter/nft_synproxy.c:60 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5704 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5817 process_backlog+0x662/0x15b0 net/core/dev.c:6149 __napi_poll+0xcb/0x490 net/core/dev.c:6902 napi_poll net/core/dev.c:6971 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7093 handle_softirqs+0x2d4/0x9b0 kernel/softirq.c:561 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244