rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (0 ticks this GP) idle=97f/1/0x4000000000000002 softirq=21801/21801 fqs=0 (detected by 1, t=10505 jiffies, g=25417, q=9006) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 10882 Comm: syz.0.2992 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:check_region_inline mm/kasan/generic.c:169 [inline] RIP: 0010:kasan_check_range+0xe/0x290 mm/kasan/generic.c:189 Code: 0f 0b b8 ea ff ff ff c3 0f 0b b8 ea ff ff ff c3 00 00 cc cc 00 00 cc cc 00 00 cc cc b0 01 48 85 f6 0f 84 ac 01 00 00 55 41 57 <41> 56 41 54 53 49 89 f8 49 01 f0 0f 82 0e 02 00 00 49 89 f8 49 c1 RSP: 0018:ffffc900000070a8 EFLAGS: 00000002 RAX: 0000000000000001 RBX: 0000000000000010 RCX: ffffffff813516bd RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc90000007250 RBP: 0000000000000000 R08: 0000000000000002 R09: ffffc90000007250 R10: dffffc0000000000 R11: fffff52000000e4c R12: 1ffffffff1ca391a R13: dffffc0000000000 R14: ffffc90000007250 R15: ffffc90000007235 FS: 00007f4b1c87d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4b1d0f10c0 CR3: 0000000072114000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: memset+0x1e/0x40 mm/kasan/shadow.c:44 unwind_next_frame+0xa3d/0x1d90 arch/x86/kernel/unwind_orc.c:547 perf_callchain_kernel+0x449/0x720 arch/x86/events/core.c:2783 get_perf_callchain+0x356/0x460 kernel/events/callchain.c:200 perf_callchain kernel/events/core.c:7606 [inline] perf_prepare_sample+0x352/0x1cd0 kernel/events/core.c:7633 __perf_event_output kernel/events/core.c:7802 [inline] perf_event_output_forward+0x185/0x2e0 kernel/events/core.c:7822 __perf_event_overflow+0x364/0x530 kernel/events/core.c:9515 perf_tp_event+0x383/0xbf0 kernel/events/core.c:10047 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 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 e2 f0 9c 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:ffffc90000007b00 EFLAGS: 00000206 RAX: 905d16ad2d1d2300 RBX: 1ffff92000000f64 RCX: 905d16ad2d1d2300 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f800 RBP: ffffc90000007bd8 R08: ffffffff901d30cf R09: 1ffffffff203a619 R10: dffffc0000000000 R11: fffffbfff203a61a R12: ffffffff8c322f00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4eb/0xb70 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:generic_exec_single+0x373/0x460 kernel/smp.c:532 Code: df eb 27 e8 7f 6c 0b 00 0f 0b e9 b6 fd ff ff e8 73 6c 0b 00 e8 fe 72 4e 08 48 85 db 0f 84 5c ff ff ff e8 60 6c 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 43 c7 44 3d RSP: 0018:ffffc9000332fa60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff8880748dd940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000332fb30 R08: ffffffff901d30cf R09: 1ffffffff203a619 R10: dffffc0000000000 R11: fffffbfff203a61a R12: ffffc9000332fb88 R13: 1ffff92000665f50 R14: 0000000000000000 R15: dffffc0000000000 smp_call_function_single+0x202/0x4c0 kernel/smp.c:755 cpu_function_call kernel/events/core.c:153 [inline] perf_install_in_context+0x528/0x920 kernel/events/core.c:2974 __do_sys_perf_event_open kernel/events/core.c:12793 [inline] __se_sys_perf_event_open+0x12b3/0x1bb0 kernel/events/core.c:12387 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4b1d21b799 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:00007f4b1c87d028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f4b1d494fa0 RCX: 00007f4b1d21b799 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00002000000003c0 RBP: 00007f4b1d2b1bd9 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b1d495038 R14: 00007f4b1d494fa0 R15: 00007ffe0857fa78 rcu: rcu_preempt kthread timer wakeup didn't happen for 10504 jiffies! g25417 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=9365 rcu: rcu_preempt kthread starved for 10505 jiffies! g25417 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:27384 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11ef/0x43c0 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2117 rcu_gp_fqs_loop+0x2be/0x11d0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x9b/0x370 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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: 10882 Comm: syz.0.2992 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 RIP: 0010:tracing_generic_entry_update include/linux/trace_events.h:160 [inline] RIP: 0010:perf_trace_buf_update+0xac/0x230 kernel/trace/trace_event_perf.c:433 Code: be 00 02 00 00 45 31 ff 48 23 74 24 40 43 c6 44 25 04 f8 41 0f 94 c7 31 ff e8 c0 26 f8 ff 44 89 ff e8 98 8d fb ff 4c 8d 7b 03 <4c> 89 f9 48 c1 e9 03 42 0f b6 0c 21 84 c9 0f 85 af 00 00 00 41 88 RSP: 0018:ffffc90000007580 EFLAGS: 00000002 RAX: 0000000000350002 RBX: ffffe8ffffc9b000 RCX: 0000000000350000 RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000000 RBP: ffffc90000007630 R08: ffff8880748dd947 R09: 1ffff1100e91bb28 R10: dffffc0000000000 R11: ffffed100e91bb29 R12: dffffc0000000000 R13: 1ffff92000000eb4 R14: 0000000000000116 R15: ffffe8ffffc9b003 FS: 00007f4b1c87d6c0(0000) GS:ffff8880b9000000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4b1d0f10c0 CR3: 0000000072114000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: perf_tp_event+0x1a2/0xbf0 kernel/events/core.c:10043 perf_trace_run_bpf_submit+0xf3/0x1c0 kernel/events/core.c:10021 perf_trace_preemptirq_template+0x2aa/0x360 include/trace/events/preemptirq.h:14 trace_irq_enable_rcuidle+0x108/0x180 include/trace/events/preemptirq.h:40 trace_hardirqs_on+0x57/0x80 kernel/trace/trace_preemptirq.c:44 asm_sysvec_irq_work+0x16/0x20 arch/x86/include/asm/idtentry.h:713 RIP: 0010:rcu_read_unlock_special+0x7f/0x4a0 kernel/rcu/tree_plugin.h:674 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 e2 f0 9c 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:ffffc90000007b00 EFLAGS: 00000206 RAX: 905d16ad2d1d2300 RBX: 1ffff92000000f64 RCX: 905d16ad2d1d2300 RDX: dffffc0000000000 RSI: ffffffff8a2b2780 RDI: ffffffff8a79f800 RBP: ffffc90000007bd8 R08: ffffffff901d30cf R09: 1ffffffff203a619 R10: dffffc0000000000 R11: fffffbfff203a61a R12: ffffffff8c322f00 R13: dffffc0000000000 R14: 0000000000000246 R15: 0000000000000001 __rcu_read_unlock+0x78/0xd0 kernel/rcu/tree_plugin.h:422 rcu_read_unlock include/linux/rcupdate.h:772 [inline] ieee80211_iterate_active_interfaces_atomic+0x132/0x140 net/mac80211/util.c:831 mac80211_hwsim_beacon+0x9b/0x180 drivers/net/wireless/mac80211_hwsim.c:1865 __run_hrtimer kernel/time/hrtimer.c:1685 [inline] __hrtimer_run_queues+0x4eb/0xb70 kernel/time/hrtimer.c:1749 hrtimer_run_softirq+0x176/0x240 kernel/time/hrtimer.c:1766 handle_softirqs+0x339/0x830 kernel/softirq.c:576 __do_softirq kernel/softirq.c:610 [inline] invoke_softirq kernel/softirq.c:450 [inline] __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline] sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:generic_exec_single+0x373/0x460 kernel/smp.c:532 Code: df eb 27 e8 7f 6c 0b 00 0f 0b e9 b6 fd ff ff e8 73 6c 0b 00 e8 fe 72 4e 08 48 85 db 0f 84 5c ff ff ff e8 60 6c 0b 00 fb 31 c0 <48> c7 44 24 20 0e 36 e0 45 4b c7 44 3d 00 00 00 00 00 43 c7 44 3d RSP: 0018:ffffc9000332fa60 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000200 RCX: ffff8880748dd940 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000332fb30 R08: ffffffff901d30cf R09: 1ffffffff203a619 R10: dffffc0000000000 R11: fffffbfff203a61a R12: ffffc9000332fb88 R13: 1ffff92000665f50 R14: 0000000000000000 R15: dffffc0000000000 smp_call_function_single+0x202/0x4c0 kernel/smp.c:755 cpu_function_call kernel/events/core.c:153 [inline] perf_install_in_context+0x528/0x920 kernel/events/core.c:2974 __do_sys_perf_event_open kernel/events/core.c:12793 [inline] __se_sys_perf_event_open+0x12b3/0x1bb0 kernel/events/core.c:12387 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f4b1d21b799 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:00007f4b1c87d028 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 00007f4b1d494fa0 RCX: 00007f4b1d21b799 RDX: 0000000000000000 RSI: ffffffffffffffff RDI: 00002000000003c0 RBP: 00007f4b1d2b1bd9 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4b1d495038 R14: 00007f4b1d494fa0 R15: 00007ffe0857fa78