rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P31610/1:b..l rcu: (detected by 0, t=10502 jiffies, g=155357, q=529 ncpus=2) task:syz.3.5866 state:R running task stack:27320 pid:31610 tgid:31610 ppid:27822 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7047 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7071 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1884 [inline] zap_pmd_range mm/memory.c:1946 [inline] zap_pud_range mm/memory.c:1975 [inline] zap_p4d_range mm/memory.c:1996 [inline] unmap_page_range+0x38be/0x4170 mm/memory.c:2017 unmap_single_vma mm/memory.c:2059 [inline] unmap_vmas+0x399/0x580 mm/memory.c:2101 exit_mmap+0x239/0xb10 mm/mmap.c:1277 __mmput+0x118/0x430 kernel/fork.c:1173 exit_mm+0x1da/0x2c0 kernel/exit.c:581 do_exit+0x658/0x2310 kernel/exit.c:959 do_group_exit+0x21c/0x2d0 kernel/exit.c:1112 __do_sys_exit_group kernel/exit.c:1123 [inline] __se_sys_exit_group kernel/exit.c:1121 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1121 x64_sys_call+0x2210/0x2210 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa58b58f749 RSP: 002b:00007ffc6a58cb08 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fa58b58f749 RDX: 00007fa58a7f9000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc6a58cb6c R08: 000000000000008c R09: 00000000000927c0 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000060 R13: 00000000000927c0 R14: 00000000000d7c20 R15: 00007ffc6a58cbc0 rcu: rcu_preempt kthread starved for 10452 jiffies! g155357 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:27136 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5256 [inline] __schedule+0x14bc/0x5000 kernel/sched/core.c:6863 __schedule_loop kernel/sched/core.c:6945 [inline] schedule+0x165/0x360 kernel/sched/core.c:6960 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 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: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:lockdep_recursion_finish kernel/locking/lockdep.c:470 [inline] RIP: 0010:lock_acquire+0x134/0x340 kernel/locking/lockdep.c:5870 Code: 00 6a 00 55 ff 74 24 30 e8 c9 02 00 00 48 83 c4 28 48 c7 c7 f0 f1 c8 8d e8 19 f0 c6 09 b8 ff ff ff ff 65 0f c1 05 3c 26 25 11 <83> f8 01 0f 85 c9 00 00 00 48 c7 44 24 30 00 00 00 00 9c 8f 44 24 RSP: 0018:ffffc90000a07a98 EFLAGS: 00000057 RAX: 0000000000000001 RBX: 0000000000000000 RCX: b3697857356f4200 RDX: 000000007a7315a3 RSI: ffffffff8dc8f1f0 RDI: ffffffff8be251e0 RBP: ffffffff81747f85 R08: ffffffff81747f85 R09: ffffffff8e341a60 R10: ffffc90000a07cb8 R11: fffff52000140f99 R12: 0000000000000002 R13: ffffffff8e341a60 R14: 0000000000000000 R15: 0000000000000246 FS: 0000000000000000(0000) GS:ffff888125ae6000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ffc9b2a4370 CR3: 000000005e24e000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000002000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:867 [inline] class_rcu_constructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0xc2/0x23d0 arch/x86/kernel/unwind_orc.c:495 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:773 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe4/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:57 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:78 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1c0/0x660 mm/slub.c:6878 ieee80211_inform_bss+0xc4e/0x1130 net/mac80211/scan.c:164 rdev_inform_bss net/wireless/rdev-ops.h:418 [inline] cfg80211_inform_single_bss_data+0xd14/0x1ad0 net/wireless/scan.c:2373 cfg80211_inform_bss_data+0x203/0x3b40 net/wireless/scan.c:3228 cfg80211_inform_bss_frame_data+0x3c7/0x710 net/wireless/scan.c:3319 ieee80211_bss_info_update+0x749/0x9e0 net/mac80211/scan.c:230 ieee80211_scan_rx+0x593/0xa20 net/mac80211/scan.c:359 __ieee80211_rx_handle_packet net/mac80211/rx.c:5282 [inline] ieee80211_rx_list+0x2485/0x2f90 net/mac80211/rx.c:5539 ieee80211_rx_napi+0x1a8/0x3d0 net/mac80211/rx.c:5562 ieee80211_rx include/net/mac80211.h:5216 [inline] ieee80211_handle_queued_frames+0xe8/0x1e0 net/mac80211/main.c:452 tasklet_action_common+0x358/0x550 kernel/softirq.c:929 handle_softirqs+0x27d/0x850 kernel/softirq.c:626 __do_softirq kernel/softirq.c:660 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xca/0x1f0 kernel/softirq.c:727 irq_exit_rcu+0x9/0x30 kernel/softirq.c:743 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 13 c0 22 00 f3 0f 1e fa fb f4 c8 ed 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000197de0 EFLAGS: 000002c6 RAX: b3697857356f4200 RBX: ffffffff8197d83a RCX: b3697857356f4200 RDX: 0000000000000001 RSI: ffffffff8daa54ce RDI: ffffffff8be251e0 RBP: ffffc90000197f10 R08: ffff8880b87336db R09: 1ffff110170e66db R10: dffffc0000000000 R11: ffffed10170e66dc R12: ffffffff8fc3cc70 R13: 1ffff11003b50b70 R14: 0000000000000001 R15: 0000000000000001 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x73/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1ea/0x520 kernel/sched/idle.c:332 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:430 start_secondary+0x101/0x110 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x147