rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=684c/1/0x4000000000000000 softirq=16320/16322 fqs=1 rcu: (detected by 1, t=10502 jiffies, g=12589, q=303 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 4293 Comm: kworker/u8:12 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Workqueue: events_unbound cfg80211_wiphy_work RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 04 e6 d8 0b 48 89 de 5b e9 03 25 5b 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 c0 79 92 65 8b 15 08 60 b8 10 81 e2 00 01 ff 00 RSP: 0018:ffffc90000007d38 EFLAGS: 00000097 RAX: ffffffff81aeccd7 RBX: ffff8880b8828388 RCX: 0000000000010000 RDX: ffff888032751e80 RSI: 0000000000000000 RDI: 0000000000000007 RBP: ffffc90000007e90 R08: ffff888142e9d19f R09: 1ffff110285d3a33 R10: dffffc0000000000 R11: ffffed10285d3a34 R12: ffff888142e9d300 R13: 0000000000000000 R14: 0000000000000001 R15: ffff888032752998 FS: 0000000000000000(0000) GS:ffff888126084000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000c004142bd0 CR3: 0000000011574000 CR4: 00000000003526f0 Call Trace: cpu_max_bits_warn include/linux/cpumask.h:136 [inline] cpumask_check include/linux/cpumask.h:143 [inline] cpumask_test_cpu include/linux/cpumask.h:647 [inline] cpu_online include/linux/cpumask.h:1229 [inline] trace_hrtimer_expire_exit include/trace/events/timer.h:306 [inline] __run_hrtimer kernel/time/hrtimer.c:1780 [inline] __hrtimer_run_queues+0x567/0xc30 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1045 [inline] __sysvec_apic_timer_interrupt+0x102/0x3e0 arch/x86/kernel/apic/apic.c:1062 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:217 [inline] RIP: 0010:unwind_next_frame+0x214/0x2390 arch/x86/kernel/unwind_orc.c:494 Code: ef 08 8b 15 9e 42 26 0c 8d 42 ff 44 39 f8 0f 86 65 18 00 00 44 89 f8 4c 8d 2c 85 08 64 bf 90 4c 89 e8 48 c1 e8 03 0f b6 04 28 <84> c0 48 89 eb 0f 85 1c 1c 00 00 45 8b 6d 00 44 89 f8 ff c0 48 8d RSP: 0018:ffffc9000d417498 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 240e15731a6baa00 RDX: 00000000000a529b RSI: ffffffff8bc00c40 RDI: ffffffff8bc00c00 RBP: dffffc0000000000 R08: ffffffff8173ff45 R09: ffffffff8df41e20 R10: ffffc9000d4175b8 R11: ffffffff81ad5380 R12: ffffffff818da200 R13: ffffffff90c19a90 R14: ffffc9000d417568 R15: 0000000000008da2 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6663 [inline] kmem_cache_free+0x197/0x620 mm/slub.c:6774 kfree_skb_reason include/linux/skbuff.h:1322 [inline] kfree_skb include/linux/skbuff.h:1331 [inline] ieee80211_iface_work+0xb2a/0x12d0 net/mac80211/iface.c:1792 cfg80211_wiphy_work+0x2ab/0x450 net/wireless/core.c:438 process_one_work kernel/workqueue.c:3257 [inline] process_scheduled_works+0xad1/0x1770 kernel/workqueue.c:3340 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3421 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: rcu_preempt kthread starved for 10457 jiffies! g12589 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:27224 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: CPU: 1 UID: 0 PID: 5966 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xccf/0x12b0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 6a 95 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 15 91 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 f9 90 RSP: 0018:ffffc90003c3f320 EFLAGS: 00000293 RAX: ffffffff81b5cf17 RBX: 1ffff1101710856d RCX: ffff888030db9e80 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90003c3f4a0 R08: ffffffff8f815077 R09: 1ffffffff1f02a0e R10: dffffc0000000000 R11: fffffbfff1f02a0f R12: ffff8880b8842b68 R13: dffffc0000000000 R14: ffff8880b893bb00 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888126184000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f93fbd156e8 CR3: 000000000dd3a000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1382 [inline] flush_tlb_mm_range+0x6b1/0x1280 arch/x86/mm/tlb.c:1472 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 free_ldt_pgtables+0x17b/0x320 arch/x86/kernel/ldt.c:411 arch_exit_mmap arch/x86/include/asm/mmu_context.h:234 [inline] exit_mmap+0x174/0xb10 mm/mmap.c:1263 __mmput+0x118/0x430 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:583 do_exit+0x658/0x2310 kernel/exit.c:961 do_group_exit+0x21c/0x2d0 kernel/exit.c:1114 get_signal+0x1285/0x1340 kernel/signal.c:3034 arch_do_signal_or_restart+0x9a/0x7a0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x87/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x2e3/0xf80 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fabbcdc2005 Code: Unable to access opcode bytes at 0x7fabbcdc1fdb. RSP: 002b:00007fabbd10fd40 EFLAGS: 00000293 ORIG_RAX: 00000000000000e6 RAX: 0000000000000000 RBX: 0000000000000002 RCX: 00007fabbcdc2005 RDX: 00007fabbd10fd80 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007fabbd10fdec R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000062 R14: 00000000000212e6 R15: 00007fabbd10fe40