rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (2 ticks this GP) idle=137c/1/0x4000000000000000 softirq=20777/20777 fqs=1 (detected by 0, t=10502 jiffies, g=29353, q=2 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6667 Comm: syz.0.829 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:valid_section include/linux/mmzone.h:1759 [inline] RIP: 0010:pfn_valid include/linux/mmzone.h:1858 [inline] RIP: 0010:__virt_addr_valid+0x234/0x540 arch/x86/mm/physaddr.c:65 Code: 01 48 c7 c7 20 b4 89 8a be 75 03 00 00 48 c7 c2 60 b4 89 8a e8 1d e1 2a 00 4d 85 ff 74 37 4c 89 f8 48 c1 e8 03 42 80 3c 20 00 <74> 08 4c 89 ff e8 f2 4f 99 00 4d 8b 2f 4c 89 ee 48 83 e6 02 31 ff RSP: 0018:ffffc900001e05c0 EFLAGS: 00000046 RAX: 1ffff11027fff25c RBX: 00000000b8f3b9f0 RCX: ffff888054961dc0 RDX: 0000000000000100 RSI: ffffffff8adf0d00 RDI: ffffffff8adf0cc0 RBP: 0000000000000001 R08: dffffc0000000000 R09: 1ffffffff215e848 R10: dffffc0000000000 R11: fffffbfff215e849 R12: dffffc0000000000 R13: dffffc0000000001 R14: ffffffff813a0eb8 R15: ffff88813fff92e0 FS: 00007fac322466c0(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000000000 CR3: 000000001e24a000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: kasan_addr_to_slab+0x9/0xc0 mm/kasan/common.c:36 __kasan_record_aux_stack+0xf/0xc0 mm/kasan/generic.c:471 irq_work_queue_on+0x10f/0x260 kernel/irq_work.c:140 rcu_read_unlock_special+0x3c9/0x510 kernel/rcu/tree_plugin.h:678 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] trace_call_bpf+0x5bb/0x6b0 kernel/trace/bpf_trace.c:137 perf_trace_run_bpf_submit+0x79/0x1c0 kernel/events/core.c:9997 perf_trace_preemptirq_template+0x268/0x320 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0xd3/0x140 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x24/0x40 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:rcu_read_unlock_special+0x7f/0x510 kernel/rcu/tree_plugin.h:685 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 92 31 95 7e 41 f7 c6 00 00 f0 00 74 40 <48> c7 44 24 40 0e 36 e0 45 4a c7 04 2b 00 00 00 00 42 c7 44 2b 08 RSP: 0018:ffffc900001e0ac0 EFLAGS: 00000206 RAX: 5fd60707c0cc8000 RBX: 1ffff9200003c160 RCX: 5fd60707c0cc8000 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0d20 RBP: ffffc900001e0bc0 R08: ffff8880b8f3580b R09: 1ffff110171e6b01 R10: dffffc0000000000 R11: ffffed10171e6b02 R12: 0000000000000246 R13: dffffc0000000000 R14: ffff8880b8f3b900 R15: 0000000000000002 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:426 rcu_read_unlock include/linux/rcupdate.h:823 [inline] ieee80211_rx_napi+0x221/0x3d0 net/mac80211/rx.c:5339 ieee80211_rx include/net/mac80211.h:4849 [inline] ieee80211_handle_queued_frames+0x105/0x1b0 net/mac80211/main.c:317 tasklet_action_common+0x2fe/0x4d0 kernel/softirq.c:827 handle_softirqs+0x2a1/0x930 kernel/softirq.c:596 __do_softirq kernel/softirq.c:630 [inline] invoke_softirq kernel/softirq.c:470 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:679 irq_exit_rcu+0x5/0x20 kernel/softirq.c:691 instr_sysvec_irq_work arch/x86/kernel/irq_work.c:17 [inline] sysvec_irq_work+0x9d/0xc0 arch/x86/kernel/irq_work.c:17 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:728 RIP: 0010:arch_atomic_read arch/x86/include/asm/atomic.h:29 [inline] RIP: 0010:atomic_read include/linux/atomic/atomic-instrumented.h:28 [inline] RIP: 0010:queued_spin_is_locked include/asm-generic/qspinlock.h:57 [inline] RIP: 0010:debug_spin_unlock kernel/locking/spinlock_debug.c:100 [inline] RIP: 0010:do_raw_spin_unlock+0x55/0x230 kernel/locking/spinlock_debug.c:140 Code: 7e 01 00 00 41 81 3e ad 4e ad de 0f 85 ed 00 00 00 48 89 df be 04 00 00 00 e8 d7 d6 6d 00 48 89 d8 48 c1 e8 03 42 0f b6 04 20 <84> c0 0f 85 6e 01 00 00 83 3b 00 0f 84 e4 00 00 00 4c 8d 73 10 4d RSP: 0018:ffffc9000c3d7bd8 EFLAGS: 00000a06 RAX: 0000000000000000 RBX: ffffc90000a13708 RCX: ffffffff81658a19 RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffc90000a13708 RBP: ffffc9000c3d7d30 R08: ffffc90000a1370b R09: 1ffff920001426e1 R10: dffffc0000000000 R11: fffff520001426e2 R12: dffffc0000000000 R13: ffffc90000a13748 R14: ffffc90000a1370c R15: ffffc9000d627c50 __raw_spin_unlock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_unlock+0x1a/0x40 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] futex_wake+0x419/0x4f0 kernel/futex/waitwake.c:183 do_futex+0x2e2/0x320 kernel/futex/syscalls.c:139 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fac3139aeb9 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:00007fac322460e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00007fac31615fa8 RCX: 00007fac3139aeb9 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fac31615fac RBP: 00007fac31615fa0 R08: 00117855a8c2b8f6 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007fac31616038 R14: 00007ffe76b15f70 R15: 00007ffe76b16058 rcu: rcu_preempt kthread starved for 10500 jiffies! g29353 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:26864 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 6664 Comm: syz.0.829 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] RIP: 0010:arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] RIP: 0010:kvm_wait+0x159/0x1b0 arch/x86/kernel/kvm.c:1064 Code: 89 df 48 89 f8 48 c1 e8 03 42 0f b6 04 30 84 c0 75 4b 0f b6 1f e8 77 39 50 00 44 38 e3 75 10 66 90 0f 00 2d 59 ce 50 09 fb f4 16 ff ff ff fb e9 10 ff ff ff e8 37 f2 f3 08 89 f9 80 e1 07 38 RSP: 0018:ffffc9000d6277c0 EFLAGS: 00000246 RAX: 9292581b77153c00 RBX: 0000000000000003 RCX: 9292581b77153c00 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: ffffffff8adf0d20 RBP: ffffc9000d627870 R08: ffffffff90af4317 R09: 1ffffffff215e862 R10: dffffc0000000000 R11: fffffbfff215e863 R12: 0000000000000003 R13: ffff8880b8e3b954 R14: dffffc0000000000 R15: 1ffff92001ac4ef8 FS: 0000555562921500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2bb53e CR3: 000000001e24a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: pv_wait arch/x86/include/asm/paravirt.h:603 [inline] pv_wait_head_or_lock kernel/locking/qspinlock_paravirt.h:470 [inline] __pv_queued_spin_lock_slowpath+0x616/0x9c0 kernel/locking/qspinlock.c:511 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:591 [inline] queued_spin_lock_slowpath+0x43/0x50 arch/x86/include/asm/qspinlock.h:51 queued_spin_lock include/asm-generic/qspinlock.h:114 [inline] do_raw_spin_lock+0x265/0x2f0 kernel/locking/spinlock_debug.c:115 spin_lock include/linux/spinlock.h:351 [inline] futex_q_lock+0x1a6/0x240 kernel/futex/core.c:542 futex_wait_setup+0xe9/0x270 kernel/futex/waitwake.c:607 futex_wait+0x1bb/0x5e0 kernel/futex/waitwake.c:651 do_futex+0x310/0x320 kernel/futex/syscalls.c:134 __do_sys_futex kernel/futex/syscalls.c:211 [inline] __se_sys_futex+0x381/0x410 kernel/futex/syscalls.c:192 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fac3139aeb9 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:00007ffe76b161b8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000003222d RCX: 00007fac3139aeb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007fac31615fac RBP: 0000000000000032 R08: 0012a982a9218082 R09: 0000000000000000 R10: 00007ffe76b162c0 R11: 0000000000000246 R12: 00007ffe76b162e0 R13: 00007fac31615fac R14: 000000000003225f R15: 00007ffe76b162c0