rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2/1:b..l rcu: (detected by 0, t=10502 jiffies, g=67113, q=722 ncpus=2) task:kthreadd state:R running task stack:23944 pid:2 tgid:2 ppid:0 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 kernel/sched/core.c:6756 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7078 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+0x264/0x550 kernel/locking/lockdep.c:5853 Code: 2b 00 74 08 4c 89 f7 e8 1a 2b 8b 00 f6 44 24 61 02 0f 85 85 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc900000774e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200000eea8 RCX: ffff888140ada8d8 RDX: dffffc0000000000 RSI: ffffffff8c0aaa40 RDI: ffffffff8c5fb020 RBP: ffffc90000077638 R08: ffffffff942a4887 R09: 1ffffffff2854910 R10: dffffc0000000000 R11: fffffbfff2854911 R12: 1ffff9200000eea4 R13: dffffc0000000000 R14: ffffc90000077540 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __page_table_check_zero+0xb1/0x350 mm/page_table_check.c:148 page_table_check_free include/linux/page_table_check.h:41 [inline] free_pages_prepare mm/page_alloc.c:1128 [inline] free_unref_page+0xd53/0x1010 mm/page_alloc.c:2659 discard_slab mm/slub.c:2688 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3157 put_cpu_partial+0x17c/0x250 mm/slub.c:3232 __slab_free+0x290/0x380 mm/slub.c:4483 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] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4329 kmalloc_noprof include/linux/slab.h:901 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] set_kthread_struct+0xb6/0x200 kernel/kthread.c:118 copy_process+0x11ed/0x3d50 kernel/fork.c:2322 kernel_clone+0x226/0x8e0 kernel/fork.c:2806 kernel_thread+0x1bc/0x240 kernel/fork.c:2868 create_kthread kernel/kthread.c:412 [inline] kthreadd+0x60d/0x810 kernel/kthread.c:767 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: rcu_preempt kthread starved for 10305 jiffies! g67113 f0x0 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:25880 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5369 [inline] __schedule+0x1850/0x4c30 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+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/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: CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.13.0-rc4-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 RIP: 0010:__find_rr_leaf+0x1b9/0x8e0 net/ipv6/route.c:809 Code: 04 00 00 44 8b 33 44 89 f6 81 e6 00 00 40 00 31 ff e8 cb e2 30 f7 44 89 f0 25 00 00 40 00 48 89 5c 24 68 75 07 e8 77 de 30 f7 64 49 8d 5c 24 30 48 89 d8 48 c1 e8 03 42 80 3c 38 00 74 08 48 RSP: 0018:ffffc90000156180 EFLAGS: 00000246 RAX: ffffffff8a6e95b9 RBX: ffff888141ff2064 RCX: ffff88801ced5a00 RDX: 0000000000000100 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900001562f8 R08: ffffffff8a6e95a5 R09: ffffc90000156430 R10: ffffc90000156420 R11: fffff5200002ac52 R12: ffff888141ff2000 R13: 1ffff110283fe40c R14: 0000000000000001 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: fffffffffffffffd CR3: 000000007e136000 CR4: 0000000000350ef0 Call Trace: find_rr_leaf net/ipv6/route.c:856 [inline] rt6_select net/ipv6/route.c:900 [inline] fib6_table_lookup+0x413/0xbb0 net/ipv6/route.c:2195 ip6_pol_route+0x273/0x15d0 net/ipv6/route.c:2231 pol_lookup_func include/net/ip6_fib.h:616 [inline] fib6_rule_lookup+0x58c/0x790 net/ipv6/fib6_rules.c:117 ip6_route_input_lookup net/ipv6/route.c:2300 [inline] ip6_route_input+0x859/0xd90 net/ipv6/route.c:2596 ip6_rcv_finish+0x144/0x180 net/ipv6/ip6_input.c:77 ip_sabotage_in+0x205/0x290 net/bridge/br_netfilter_hooks.c:1021 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 __netif_receive_skb_one_core net/core/dev.c:5672 [inline] __netif_receive_skb+0x1ea/0x650 net/core/dev.c:5785 netif_receive_skb_internal net/core/dev.c:5871 [inline] netif_receive_skb+0x1e8/0x890 net/core/dev.c:5930 NF_HOOK+0xa0/0x400 include/linux/netfilter.h:314 br_handle_frame_finish+0x18ed/0x1fe0 br_nf_hook_thresh+0x474/0x590 br_nf_pre_routing_finish_ipv6+0xaa0/0xdd0 NF_HOOK include/linux/netfilter.h:314 [inline] br_nf_pre_routing_ipv6+0x379/0x770 net/bridge/br_netfilter_ipv6.c:184 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_bridge_pre net/bridge/br_input.c:277 [inline] br_handle_frame+0x9ff/0x1530 net/bridge/br_input.c:424 __netif_receive_skb_core+0x14ed/0x4690 net/core/dev.c:5566 __netif_receive_skb_one_core net/core/dev.c:5670 [inline] __netif_receive_skb+0x12f/0x650 net/core/dev.c:5785 process_backlog+0x662/0x15b0 net/core/dev.c:6117 __napi_poll+0xcd/0x490 net/core/dev.c:6883 napi_poll net/core/dev.c:6952 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7074 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:561 run_ksoftirqd+0xca/0x130 kernel/softirq.c:950 smpboot_thread_fn+0x546/0xa30 kernel/smpboot.c:164 kthread+0x2f2/0x390 kernel/kthread.c:389 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244