rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (10401 ticks this GP) idle=af24/1/0x4000000000000000 softirq=14849/14849 fqs=13 rcu: (t=10500 jiffies g=14405 q=478 ncpus=2) rcu: rcu_preempt kthread starved for 10472 jiffies! g14405 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:26960 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5381 [inline] __schedule+0x1553/0x45a0 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+0x313/0x1590 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: 6683 Comm: syz.0.247 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:434 [inline] RIP: 0010:__pv_queued_spin_lock_slowpath+0x532/0x9d0 kernel/locking/qspinlock.c:511 Code: 00 41 c6 45 00 00 48 8b 44 24 10 42 0f b6 04 38 84 c0 0f 85 1b 01 00 00 48 8b 44 24 08 c6 00 01 41 bd 00 80 ff ff eb 07 f3 90 <41> ff c5 74 47 43 0f b6 04 3e 84 c0 75 2b 80 3b 00 75 eb 48 89 df RSP: 0018:ffffc90003947960 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffffc90000a36e88 RCX: ffff88801b3f3c00 RDX: 0000000000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8e60 RBP: ffffc90003947a50 R08: ffffffff911c55ff R09: 1ffffffff2238abf R10: dffffc0000000000 R11: fffffbfff2238ac0 R12: 1ffff110171c0001 R13: 00000000ffffd82a R14: 1ffff92000146dd1 R15: dffffc0000000000 FS: 000055557e8cc500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffff80000000 CR3: 000000002fce7000 CR4: 00000000003506f0 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/0x2c0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:351 [inline] futex_unqueue+0x4e/0xf0 kernel/futex/core.c:597 futex_wait+0x1f4/0x5e0 kernel/futex/waitwake.c:660 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+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2f7e19c819 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:00007ffdfe6aacf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000001f54e RCX: 00007f2f7e19c819 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f2f7e415fac RBP: 0000000000000032 R08: 0000000000745d1e R09: 0000000000000000 R10: 00007ffdfe6aae00 R11: 0000000000000246 R12: 00007ffdfe6aae20 R13: 00007f2f7e415fac R14: 000000000001f580 R15: 00007ffdfe6aae00 CPU: 1 PID: 6684 Comm: syz.0.247 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026 RIP: 0010:rcu_read_unlock_special+0x83/0x4d0 kernel/rcu/tree_plugin.h:763 Code: eb 03 48 b8 f1 f1 f1 f1 f8 f2 f2 f2 4a 89 04 2b 42 c7 44 2b 08 f8 f3 f3 f3 65 44 8b 35 6e 02 92 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 20 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001f0400 EFLAGS: 00000206 RAX: 04624b66299aba00 RBX: 1ffff9200003e084 RCX: 04624b66299aba00 RDX: dffffc0000000000 RSI: ffffffff8acac9e0 RDI: ffffffff8b1c8e60 RBP: ffffc900001f04c8 R08: ffffffff911c5607 R09: 1ffffffff2238ac0 R10: dffffc0000000000 R11: fffffbfff2238ac1 R12: ffffffff8d137300 R13: dffffc0000000000 R14: ffff8880b8f3cf50 R15: 1ffff110171e79ea FS: 00007f2f7f0616c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000002fce7000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: __rcu_read_unlock+0x7c/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:818 [inline] is_bpf_text_address+0x27e/0x2a0 kernel/bpf/core.c:743 kernel_text_address+0xa0/0xd0 kernel/extable.c:125 __kernel_text_address+0xd/0x30 kernel/extable.c:79 unwind_get_return_address+0x5d/0xc0 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0x11d/0x190 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:46 [inline] kasan_set_track+0x4e/0x70 mm/kasan/common.c:53 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6e/0x4b0 mm/slab.h:767 slab_alloc_node mm/slub.c:3495 [inline] kmem_cache_alloc_node+0x14c/0x320 mm/slub.c:3540 __alloc_skb+0x103/0x2c0 net/core/skbuff.c:643 alloc_skb include/linux/skbuff.h:1316 [inline] ndisc_alloc_skb+0xa6/0x450 net/ipv6/ndisc.c:423 ndisc_send_rs+0x2a6/0x610 net/ipv6/ndisc.c:707 addrconf_rs_timer+0x2d5/0x630 net/ipv6/addrconf.c:4024 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x542/0x800 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x280/0x820 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:kasan_check_range+0x1c2/0x290 mm/kasan/generic.c:-1 Code: 5c 24 07 4d 85 e4 49 0f 49 dc 48 83 e3 f8 49 29 dc 74 0e 41 80 3b 00 75 6b 49 ff c3 49 ff cc 75 f2 5b 41 5c 41 5d 41 5e 41 5f <5d> c3 45 84 ff 0f 85 91 00 00 00 41 f7 c7 00 ff 00 00 0f 85 89 00 RSP: 0018:ffffc900036b7bd8 EFLAGS: 00000256 RAX: 1ffff92000728f01 RBX: ffffc900036b7cc0 RCX: ffffffff817bc3f3 RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffff88801b3f3c28 RBP: ffffc900036b7d30 R08: ffff88801b3f3c2b R09: 1ffff1100367e785 R10: dffffc0000000000 R11: ffffed100367e786 R12: ffff88801b3f3c28 R13: dffffc0000000000 R14: ffffc90003947c50 R15: ffff88801b3f3c00 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_fetch_add_relaxed include/linux/atomic/atomic-instrumented.h:252 [inline] __refcount_add include/linux/refcount.h:193 [inline] __refcount_inc include/linux/refcount.h:250 [inline] refcount_inc include/linux/refcount.h:267 [inline] get_task_struct include/linux/sched/task.h:117 [inline] futex_wake_mark+0xb3/0x150 kernel/futex/waitwake.c:122 futex_wake+0x32f/0x4f0 kernel/futex/waitwake.c:177 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+0x55/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f2f7e19c819 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:00007f2f7f0610e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007f2f7e415fa8 RCX: 00007f2f7e19c819 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f2f7e415fac RBP: 00007f2f7e415fa0 R08: 0000000000745d1e R09: 0000000000000000 R10: 0000000000000004 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f2f7e416038 R14: 00007ffdfe6aaab0 R15: 00007ffdfe6aab98