rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10483 ticks this GP) idle=065c/1/0x4000000000000000 softirq=39188/39188 fqs=7 rcu: (t=10500 jiffies g=46349 q=303 ncpus=2) rcu: rcu_preempt kthread starved for 10482 jiffies! g46349 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:27048 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6700 schedule+0xbd/0x170 kernel/sched/core.c:6774 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 11713 Comm: syz.2.1669 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x52e/0x9c0 kernel/locking/qspinlock.c:511 Code: 8b 44 24 18 c6 00 00 48 8b 44 24 10 42 0f b6 04 28 84 c0 0f 85 1b 01 00 00 48 8d 43 01 c6 00 01 41 bc 00 80 ff ff eb 07 f3 90 <41> ff c4 74 47 43 0f b6 04 2e 84 c0 75 2b 80 3b 00 75 eb 48 89 df RSP: 0018:ffffc900053278a0 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffffc90000a40888 RCX: ffff88802a538000 RDX: 0000000000000000 RSI: ffffffff8acacb60 RDI: ffffffff8b1cfa20 RBP: ffffc90005327990 R08: ffffffff911e75ff R09: 1ffffffff223cebf R10: dffffc0000000000 R11: fffffbfff223cec0 R12: 00000000ffffe4b9 R13: dffffc0000000000 R14: 1ffff92000148111 R15: ffff8880b8e30001 FS: 0000555593425500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f5667e27dac CR3: 0000000069423000 CR4: 00000000003506f0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:586 [inline] queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:51 [inline] queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x23e/0x2b0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:351 [inline] futex_q_lock+0x1aa/0x250 kernel/futex/core.c:542 futex_wait_setup+0xed/0x270 kernel/futex/waitwake.c:607 futex_wait+0x1bc/0x5c0 kernel/futex/waitwake.c:651 do_futex+0x2ff/0x3e0 kernel/futex/syscalls.c:134 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x3a9/0x440 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f02b959de59 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:00007ffec734b648 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000006550a RCX: 00007f02b959de59 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f02b9825fac RBP: 0000000000000032 R08: 0000000000745d1e R09: 0000000000000000 R10: 00007ffec734b750 R11: 0000000000000246 R12: 00007ffec734b770 R13: 00007f02b9825fac R14: 000000000006553c R15: 00007ffec734b750 CPU: 1 PID: 11714 Comm: syz.2.1669 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/25/2026 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 9b ed c6 f6 65 8b 05 6c 3c 6e 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc900001f0020 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: 8750f5f4ab64d000 RDX: dffffc0000000000 RSI: ffffffff8acacb60 RDI: 0000000000000001 RBP: ffffc900001f00b0 R08: ffffffff911e75ef R09: 1ffffffff223cebd R10: dffffc0000000000 R11: fffffbfff223cebe R12: dffffc0000000000 R13: ffff88805f4d1ea8 R14: ffffffff9754c4b8 R15: 1ffff9200003e004 FS: 00007f02ba4816c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 0000000069423000 CR4: 00000000003506e0 DR0: 0000200000000300 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: debug_object_activate+0x307/0x500 lib/debugobjects.c:765 debug_rcu_head_queue kernel/rcu/rcu.h:227 [inline] __call_rcu_common kernel/rcu/tree.c:2706 [inline] call_rcu+0xa6/0x900 kernel/rcu/tree.c:2837 refdst_drop include/net/dst.h:270 [inline] skb_dst_drop include/net/dst.h:282 [inline] skb_release_head_state+0x71/0x240 net/core/skbuff.c:1037 skb_release_all net/core/skbuff.c:1052 [inline] __kfree_skb net/core/skbuff.c:1068 [inline] kfree_skb_reason+0xd7/0x170 net/core/skbuff.c:1104 kfree_skb include/linux/skbuff.h:1264 [inline] vti6_tnl_xmit+0x13e7/0x19c0 net/ipv6/ip6_vti.c:596 __netdev_start_xmit include/linux/netdevice.h:4943 [inline] netdev_start_xmit include/linux/netdevice.h:4957 [inline] xmit_one net/core/dev.c:3644 [inline] dev_hard_start_xmit+0x269/0x790 net/core/dev.c:3660 __dev_queue_xmit+0x198c/0x3630 net/core/dev.c:4454 neigh_output include/net/neighbour.h:543 [inline] ip6_finish_output2+0xe2e/0x1620 net/ipv6/ip6_output.c:141 dst_output include/net/dst.h:467 [inline] NF_HOOK include/linux/netfilter.h:304 [inline] ndisc_send_skb+0xbb9/0x1480 net/ipv6/ndisc.c:513 addrconf_rs_timer+0x36b/0x640 net/ipv6/addrconf.c:4029 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x570/0x810 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:check_region_inline mm/kasan/generic.c:-1 [inline] RIP: 0010:kasan_check_range+0x10/0x290 mm/kasan/generic.c:187 Code: c0 c3 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 cc cc cc cc cc cc cc cc 66 0f 1f 00 b0 01 48 85 f6 0f 84 b4 01 00 00 55 <41> 57 41 56 41 55 41 54 53 4c 8d 04 37 49 39 f8 0f 82 13 02 00 00 RSP: 0018:ffffc900051b7bc8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffc90000a40888 RCX: ffffffff8169598d RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffc90000a40888 RBP: ffffc900051b7d30 R08: ffffffff8e8c6b2f R09: 1ffffffff1d18d65 R10: dffffc0000000000 R11: fffffbfff1d18d66 R12: dffffc0000000000 R13: ffffc90000a408c8 R14: ffffc90000a4088c R15: ffffc90005327c50 instrument_atomic_read include/linux/instrumented.h:68 [inline] atomic_read include/linux/atomic/atomic-instrumented.h:32 [inline] queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline] do_raw_spin_unlock+0x4d/0x230 kernel/locking/spinlock_debug.c:140 __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_unlock+0x1e/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] futex_wake+0x41d/0x4f0 kernel/futex/waitwake.c:183 do_futex+0x35d/0x3e0 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x3a9/0x440 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f02b959de59 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:00007f02ba4810e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f02b9825fa8 RCX: 00007f02b959de59 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f02b9825fac RBP: 00007f02b9825fa0 R08: 0000000000745d1e R09: 0000000000000000 R10: 0000000000000009 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f02b9826038 R14: 00007ffec734b400 R15: 00007ffec734b4e8