rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=3a3c/1/0x4000000000000000 softirq=69359/69360 fqs=0 rcu: (detected by 0, t=10505 jiffies, g=71221, q=382 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 16112 Comm: syz.9.3116 Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:472 [inline] RIP: 0010:lock_acquire+0x124/0x360 kernel/locking/lockdep.c:5868 Code: 02 00 00 41 0f 94 c1 4c 89 ef 89 de 8b 54 24 04 44 89 e1 45 89 f0 6a 00 6a 00 6a 00 55 ff 74 24 30 e8 e0 02 00 00 48 83 c4 28 <48> c7 c7 29 40 93 8d e8 00 b6 b7 09 b8 ff ff ff ff 65 0f c1 05 43 RSP: 0018:ffffc90000a08bd0 EFLAGS: 00000092 RAX: 0000000000000001 RBX: 0000000000000000 RCX: dcaee4296fd44c00 RDX: 0000000000000001 RSI: ffff8880120c65b8 RDI: ffff8880120c5a00 RBP: ffffffff8976fee8 R08: 0000000000000000 R09: 0000000000080000 R10: 0000000000000000 R11: ffffffff8976fee8 R12: 0000000000000002 R13: ffffffff8df3b860 R14: 0000000000000000 R15: 0000000000000046 FS: 00007fb2d01d36c0(0000) GS:ffff8881261cc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c440776 CR3: 0000000055925000 CR4: 0000000000350ef0 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] advance_sched+0xa14/0xc90 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 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:obj_cgroup_charge+0x3b1/0x6f0 mm/memcontrol.c:2974 Code: e8 d4 c4 9d ff 48 c7 44 24 60 00 00 00 00 9c 8f 44 24 60 f6 44 24 61 02 0f 85 c7 00 00 00 41 f7 c7 00 02 00 00 74 01 fb 31 c0 <45> 84 e4 75 54 48 8b 4c 24 10 48 89 c8 48 c1 e8 0c 31 d2 f7 c1 ff RSP: 0018:ffffc9000c5b6a20 EFLAGS: 00000246 RAX: 0000000000000000 RBX: dffffc0000000000 RCX: dcaee4296fd44c00 RDX: 0000000000000002 RSI: ffffffff8d748fd9 RDI: ffffffff8bc1cde0 RBP: ffffc9000c5b6b10 R08: ffffffff8f7ec977 R09: 1ffffffff1efd92e R10: dffffc0000000000 R11: fffffbfff1efd92f R12: 0000000000000801 R13: ffff8880b89349e8 R14: 1ffff920018b6d4c R15: 0000000000000212 __memcg_slab_post_alloc_hook+0x1b7/0x820 mm/memcontrol.c:3067 memcg_slab_post_alloc_hook mm/slub.c:2197 [inline] slab_post_alloc_hook mm/slub.c:4171 [inline] slab_alloc_node mm/slub.c:4210 [inline] kmem_cache_alloc_noprof+0x2bf/0x3c0 mm/slub.c:4217 dst_alloc+0x105/0x170 net/core/dst.c:89 ip6_dst_alloc net/ipv6/route.c:342 [inline] ip6_rt_pcpu_alloc net/ipv6/route.c:1418 [inline] rt6_make_pcpu_route net/ipv6/route.c:1467 [inline] ip6_pol_route+0xa21/0x1180 net/ipv6/route.c:2302 pol_lookup_func include/net/ip6_fib.h:616 [inline] fib6_rule_lookup+0x348/0x6f0 net/ipv6/fib6_rules.c:125 ip6_route_output_flags_noref net/ipv6/route.c:2674 [inline] ip6_route_output_flags+0x364/0x5d0 net/ipv6/route.c:2686 ip6_route_output include/net/ip6_route.h:93 [inline] ip6_tnl_xmit+0x584/0x2b00 net/ipv6/ip6_tunnel.c:1165 __gre6_xmit+0xa47/0xd40 net/ipv6/ip6_gre.c:816 ip6gre_xmit_other net/ipv6/ip6_gre.c:902 [inline] ip6gre_tunnel_xmit+0xb1f/0x10e0 net/ipv6/ip6_gre.c:929 __netdev_start_xmit include/linux/netdevice.h:5203 [inline] netdev_start_xmit include/linux/netdevice.h:5212 [inline] xmit_one net/core/dev.c:3776 [inline] dev_hard_start_xmit+0x302/0x880 net/core/dev.c:3792 sch_direct_xmit+0x241/0x4b0 net/sched/sch_generic.c:343 __dev_xmit_skb net/core/dev.c:4018 [inline] __dev_queue_xmit+0x17b6/0x3a70 net/core/dev.c:4595 packet_snd net/packet/af_packet.c:3131 [inline] packet_sendmsg+0x41be/0x5400 net/packet/af_packet.c:3163 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:727 __sys_sendto+0x3bd/0x520 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+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb2d278e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007fb2d01d3038 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fb2d29b6240 RCX: 00007fb2d278e969 RDX: 000000000000000e RSI: 00002000000000c0 RDI: 0000000000000003 RBP: 00007fb2d2810ab1 R08: 0000200000000140 R09: 0000000000000014 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fb2d29b6240 R15: 00007ffd5c8a0068 rcu: rcu_preempt kthread starved for 10505 jiffies! g71221 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 53 Comm: kworker/u8:3 Not tainted 6.15.0-rc3-syzkaller-00342-g5bc1018675ec #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xe6e/0x11c0 kernel/smp.c:885 Code: 89 ee 83 e6 01 31 ff e8 20 6d 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 cb 68 0b 00 eb 37 f3 90 43 0f b6 04 2c <84> c0 75 10 41 f7 07 01 00 00 00 74 1e e8 b0 68 0b 00 eb e5 44 89 RSP: 0018:ffffc90000bf7700 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b883ad40 RCX: ffff8881412d3c00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000bf7860 R08: ffffffff8f7ec977 R09: 1ffffffff1efd92e R10: dffffc0000000000 R11: fffffbfff1efd92f R12: 1ffff11017127e99 R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b893f4c8 FS: 0000000000000000(0000) GS:ffff8881260cc000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2f817ff8 CR3: 000000000dd36000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2455 [inline] text_poke_bp_batch+0x319/0x940 arch/x86/kernel/alternative.c:2665 text_poke_flush arch/x86/kernel/alternative.c:2856 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xade/0x17a0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x4e/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245