rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7990/1:b..l rcu: (detected by 0, t=10503 jiffies, g=205005, q=428 ncpus=2) task:syz-executor state:R running task stack:22824 pid:7990 tgid:7990 ppid:7969 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7502 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753 trace_notifier_run include/trace/events/notifier.h:59 [inline] notifier_call_chain+0x160/0x3d0 kernel/notifier.c:84 atomic_notifier_call_chain+0xda/0x180 kernel/notifier.c:223 ipv6_add_addr+0xe18/0x1110 net/ipv6/addrconf.c:1186 inet6_addr_add+0x43c/0xb50 net/ipv6/addrconf.c:3052 inet6_rtm_newaddr+0x9f3/0xdf0 net/ipv6/addrconf.c:5073 rtnetlink_rcv_msg+0x802/0xc00 net/core/rtnetlink.c:6997 netlink_rcv_skb+0x226/0x4a0 net/netlink/af_netlink.c:2555 netlink_unicast_kernel net/netlink/af_netlink.c:1318 [inline] netlink_unicast+0x7bb/0x940 net/netlink/af_netlink.c:1344 netlink_sendmsg+0x813/0xb40 net/netlink/af_netlink.c:1899 sock_sendmsg_nosec net/socket.c:775 [inline] __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x672/0x710 net/socket.c:2254 __do_sys_sendto net/socket.c:2261 [inline] __se_sys_sendto net/socket.c:2257 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2257 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbb9c35d68e RSP: 002b:00007fffaafa9628 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000555576848500 RCX: 00007fbb9c35d68e RDX: 0000000000000040 RSI: 00007fbb9d144670 RDI: 0000000000000003 RBP: 0000000000000001 R08: 00007fffaafa96a4 R09: 000000000000000c R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000003 R13: 0000000000000000 R14: 00007fbb9d144670 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10465 jiffies! g205005 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 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:28152 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5504 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7228 __schedule_loop kernel/sched/core.c:7307 [inline] schedule+0x164/0x360 kernel/sched/core.c:7322 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 8400 Comm: syz.6.8871 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026 RIP: 0010:rcu_read_lock include/linux/rcupdate.h:841 [inline] RIP: 0010:advance_sched+0xa1a/0xc80 net/sched/sch_taprio.c:992 Code: f6 31 d2 b9 02 00 00 00 45 31 c0 45 31 c9 53 e8 5c 34 ee f7 48 83 c4 08 e8 33 70 ef 01 89 c5 31 ff 89 c6 e8 18 6e 12 f8 85 ed <74> 10 e8 cf 5d f7 f7 84 c0 74 0e e8 c6 69 12 f8 eb 56 e8 bf 69 12 RSP: 0018:ffffc90000a08d10 EFLAGS: 00000046 RAX: ffffffff89b39a58 RBX: ffffffff89b39a28 RCX: 0000000000010000 RDX: ffff8880a7693e00 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed10125b1856 R12: ffff88805b187c00 R13: ffff888092d8c000 R14: dffffc0000000000 R15: ffff888092d8c340 FS: 00007f2c8429f6c0(0000) GS:ffff8881253aa000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 0000000099bc6000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:2032 [inline] __hrtimer_run_queues+0x3bc/0xa10 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x448/0x910 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x102/0x430 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0x47/0x80 kernel/locking/spinlock.c:198 Code: f7 e8 1d ba fc f5 f7 c3 00 02 00 00 74 05 e8 f0 75 28 f6 9c 58 a9 00 02 00 00 75 27 f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 b4 d5 ed f5 65 8b 05 5d a5 91 07 85 c0 74 18 5b 41 5e e9 2c 86 RSP: 0018:ffffc900046c7aa8 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000246 RCX: 0000000080000002 RDX: 0000000000000000 RSI: ffffffff8c28c780 RDI: 0000000000000001 RBP: ffffc900046c7bd0 R08: ffffffff902ff2f7 R09: 1ffffffff205fe5e R10: dffffc0000000000 R11: fffffbfff205fe5f R12: dffffc0000000000 R13: 0000000000000000 R14: ffffffff9a470958 R15: 1ffff920008d8f64 class_raw_spinlock_irqsave_destructor include/linux/spinlock.h:573 [inline] __do_adjtimex+0xb2c/0xe40 kernel/time/timekeeping.c:2984 do_adjtimex+0xd1/0x370 kernel/time/timekeeping.c:2995 do_clock_adjtime kernel/time/posix-timers.c:1169 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1181 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1172 [inline] __x64_sys_clock_adjtime+0x252/0x340 kernel/time/posix-timers.c:1172 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2c8339ce59 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2c8429f028 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f2c83616270 RCX: 00007f2c8339ce59 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f2c83432d6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2c83616308 R14: 00007f2c83616270 R15: 00007ffc41364308