rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=e4a4/1/0x4000000000000000 softirq=29142/29142 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6585/1:b..l rcu: (detected by 1, t=10502 jiffies, g=18881, q=368 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 6715 Comm: syz.3.19 Not tainted 6.15.0-rc6-syzkaller-g83a896549f92 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:23 [inline] RIP: 0010:raw_atomic_read include/linux/atomic/atomic-arch-fallback.h:457 [inline] RIP: 0010:rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] RIP: 0010:rcu_is_watching+0x5a/0xb0 kernel/rcu/tree.c:736 Code: f0 48 c1 e8 03 42 80 3c 38 00 74 08 4c 89 f7 e8 cc ab 78 00 48 c7 c3 58 9b 73 92 49 03 1e 48 89 d8 48 c1 e8 03 42 0f b6 04 38 <84> c0 75 34 8b 03 65 ff 0d 29 57 cb 10 74 11 83 e0 04 c1 e8 02 5b RSP: 0018:ffffc90000007be8 EFLAGS: 00000802 RAX: 0000000000000000 RBX: ffff8880b8832b58 RCX: f779c7b578063400 RDX: 0000000000010000 RSI: ffffffff8bc10820 RDI: ffffffff8bc107e0 RBP: 0000000000000001 R08: ffff888023a1715f R09: 1ffff11004742e2b R10: dffffc0000000000 R11: ffffed1004742e2c R12: ffff888023a17360 R13: ffffffff8970e128 R14: ffffffff8d95bc20 R15: dffffc0000000000 FS: 00007f1c3ffba6c0(0000) GS:ffff8881260f9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f1c3ff98f98 CR3: 000000005b6da000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5877 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] advance_sched+0xb23/0xc90 net/sched/sch_taprio.c:987 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x529/0xc60 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+0x108/0x410 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:lockdep_unregister_key+0x2ba/0x310 kernel/locking/lockdep.c:6613 Code: 00 65 48 8b 05 27 0c d4 10 48 3b 44 24 10 0f 84 30 fe ff ff e8 57 02 b1 09 e8 82 03 b1 09 41 f7 c7 00 02 00 00 74 be fb 84 db <75> bd eb ce 90 0f 0b 90 31 db eb 89 90 0f 0b 90 e9 36 ff ff ff 48 RSP: 0018:ffffc9000399f0e8 EFLAGS: 00000246 RAX: f779c7b578063400 RBX: 0000000000000000 RCX: f779c7b578063400 RDX: ffffffff93360708 RSI: ffffffff8d74c894 RDI: ffffffff8bc10840 RBP: ffff88807e4a1299 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff81ab2b48 R12: 0000000000000000 R13: 0000000000001000 R14: 0000000000000000 R15: 0000000000000a06 __qdisc_destroy+0x166/0x3f0 net/sched/sch_generic.c:1080 taprio_attach+0x25a/0x380 net/sched/sch_taprio.c:2147 qdisc_graft+0x1172/0x1590 net/sched/sch_api.c:1175 __tc_modify_qdisc net/sched/sch_api.c:1765 [inline] tc_modify_qdisc+0x1846/0x20b0 net/sched/sch_api.c:1821 rtnetlink_rcv_msg+0x779/0xb70 net/core/rtnetlink.c:6964 netlink_rcv_skb+0x21c/0x490 net/netlink/af_netlink.c:2534 netlink_unicast_kernel net/netlink/af_netlink.c:1313 [inline] netlink_unicast+0x758/0x8d0 net/netlink/af_netlink.c:1339 netlink_sendmsg+0x805/0xb30 net/netlink/af_netlink.c:1883 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x21c/0x270 net/socket.c:727 ____sys_sendmsg+0x505/0x830 net/socket.c:2566 ___sys_sendmsg+0x21f/0x2a0 net/socket.c:2620 __sys_sendmsg net/socket.c:2652 [inline] __do_sys_sendmsg net/socket.c:2657 [inline] __se_sys_sendmsg net/socket.c:2655 [inline] __x64_sys_sendmsg+0x19b/0x260 net/socket.c:2655 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: 0033:0x7f1c3f18d0a9 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:00007f1c3ffba038 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f1c3f3a5fa0 RCX: 00007f1c3f18d0a9 RDX: 0000000000000000 RSI: 00004000000007c0 RDI: 0000000000000004 RBP: 00007f1c3f20e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f1c3f3a5fa0 R15: 00007ffc1ba52048 task:syz-executor state:R running task stack:22008 pid:6585 tgid:6585 ppid:6583 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 kernel/sched/core.c:6767 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:orc_ip arch/x86/kernel/unwind_orc.c:80 [inline] RIP: 0010:__orc_find arch/x86/kernel/unwind_orc.c:102 [inline] RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:227 [inline] RIP: 0010:unwind_next_frame+0x130e/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: c1 e8 3f 48 01 c8 48 83 e0 fe 4c 8d 3c 45 00 00 00 00 49 01 ef 4c 89 f8 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df 0f b6 04 08 <84> c0 75 27 49 63 07 4c 01 f8 49 8d 4f 04 4c 39 e0 48 0f 46 e9 49 RSP: 0018:ffffc900041ff0f8 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffffffff8fecb6c8 RCX: dffffc0000000000 RDX: ffffffff8fecb6c8 RSI: ffffffff90950232 RDI: ffffffff8bc107e0 RBP: ffffffff8fecb6c8 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8171ca05 R12: ffffffff897ec8ab R13: ffffffff8fecb6c8 R14: ffffc900041ff1c8 R15: ffffffff8fecb6c8 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kvmalloc_node_noprof+0x314/0x5e0 mm/slub.c:5012 allocate_hook_entries_size net/netfilter/core.c:61 [inline] nf_hook_entries_grow+0x27c/0x6d0 net/netfilter/core.c:140 __nf_register_net_hook+0x2c9/0x930 net/netfilter/core.c:435 nf_register_net_hook+0xb2/0x190 net/netfilter/core.c:578 nf_register_net_hooks+0x44/0x1b0 net/netfilter/core.c:594 ip6t_register_table+0x534/0x7d0 net/ipv6/netfilter/ip6_tables.c:1787 ip6table_mangle_table_init+0x41/0x70 net/ipv6/netfilter/ip6table_mangle.c:85 xt_find_table_lock+0x309/0x3e0 net/netfilter/x_tables.c:1260 xt_request_find_table_lock+0x26/0x100 net/netfilter/x_tables.c:1285 get_info net/ipv6/netfilter/ip6_tables.c:979 [inline] do_ip6t_get_ctl+0x730/0x1180 net/ipv6/netfilter/ip6_tables.c:1668 nf_getsockopt+0x26e/0x290 net/netfilter/nf_sockopt.c:116 ipv6_getsockopt+0x1ed/0x290 net/ipv6/ipv6_sockglue.c:1493 do_sock_getsockopt+0x360/0x650 net/socket.c:2357 __sys_getsockopt net/socket.c:2386 [inline] __do_sys_getsockopt net/socket.c:2393 [inline] __se_sys_getsockopt net/socket.c:2390 [inline] __x64_sys_getsockopt+0x1a5/0x250 net/socket.c:2390 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: 0033:0x7fb14ad8edea RSP: 002b:00007fff253eebb8 EFLAGS: 00000242 ORIG_RAX: 0000000000000037 RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 00007fb14ad8edea RDX: 0000000000000040 RSI: 0000000000000029 RDI: 0000000000000003 RBP: 0000000000000029 R08: 00007fff253eebdc R09: 00007fff253eebe0 R10: 00007fb14af78a08 R11: 0000000000000242 R12: 00007fb14ae280ce R13: 00007fb14af79e40 R14: 00007fb14af78a08 R15: 00007fb14af78a00 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g18881 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=5951 rcu: rcu_preempt kthread starved for 10502 jiffies! g18881 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27032 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x168f/0x4c70 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+0x70e/0x8a0 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