rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=2c6c/1/0x4000000000000000 softirq=29575/29576 fqs=86 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7795/1:b..l P7794/2:b..l rcu: (detected by 1, t=10502 jiffies, g=17557, q=205 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 7792 Comm: syz.1.575 Not tainted 6.15.0-rc7-syzkaller-00099-g94305e83eccb #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:lookup_object lib/debugobjects.c:423 [inline] RIP: 0010:lookup_object_or_alloc lib/debugobjects.c:662 [inline] RIP: 0010:debug_object_activate+0x1bc/0x4c0 lib/debugobjects.c:820 Code: 80 3c 30 00 0f 85 56 02 00 00 48 8b 1b 48 85 db 0f 84 4b 01 00 00 48 8d 7b 18 41 83 c4 01 48 89 f8 48 c1 e8 03 42 80 3c 30 00 <0f> 85 0a 02 00 00 4c 3b 6b 18 75 c2 48 85 db 0f 84 e4 01 00 00 48 RSP: 0018:ffffc90000007d20 EFLAGS: 00000046 RAX: 1ffff110060e0e9d RBX: ffff8880307074d0 RCX: ffffffff8198704c RDX: ffffffff8b8fde80 RSI: 0000000000000004 RDI: ffff8880307074e8 RBP: ffffc90000007e08 R08: 0000000000000001 R09: fffff52000000f92 R10: 0000000000000002 R11: ffffffff9ad6a6a0 R12: 0000000000000005 R13: ffff88802b240340 R14: dffffc0000000000 R15: 1ffff92000000fa8 FS: 000055555b5a9500(0000) GS:ffff8881249da000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2e319ff8 CR3: 000000005b3e8000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x23/0x3b0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x8ff/0xad0 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x108/0x3f0 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5250 Code: fb 09 00 00 44 8b 05 49 cb fb 0e 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 ff 77 39 00 fb 65 48 8b 1d 8e cd 1a 12 <48> 8d bb 18 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc900038df860 EFLAGS: 00000202 RAX: 0000000000000a89 RBX: ffff888026c1c880 RCX: ffffffff81c3097f RDX: 0000000000000000 RSI: ffffffff8dbe4425 RDI: ffffffff8bf4a2e0 RBP: ffffc900038df8a8 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90852e17 R11: 0000000000000000 R12: ffff8880b8439dc0 R13: ffff88805b164880 R14: 0000000000000001 R15: ffff8880b843abf0 context_switch kernel/sched/core.c:5385 [inline] __schedule+0x1177/0x5de0 kernel/sched/core.c:6767 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6947 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 futex_wait_queue+0xad/0x220 kernel/futex/waitwake.c:356 __futex_wait+0x290/0x3c0 kernel/futex/waitwake.c:668 futex_wait+0xe8/0x380 kernel/futex/waitwake.c:696 do_futex+0x229/0x350 kernel/futex/syscalls.c:102 __do_sys_futex kernel/futex/syscalls.c:179 [inline] __se_sys_futex kernel/futex/syscalls.c:160 [inline] __x64_sys_futex+0x1e0/0x4c0 kernel/futex/syscalls.c:160 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f659dd8e969 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007ffca3f58168 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000002f91f RCX: 00007f659dd8e969 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f659dfb608c RBP: 0000000000000032 R08: 00007f659ec8a000 R09: 0000000fa3f5845f R10: 00007ffca3f58260 R11: 0000000000000246 R12: 00007f659dfb608c R13: 00007ffca3f58260 R14: 000000000002f951 R15: 00007ffca3f58280 task:syz-executor state:R running task stack:28456 pid:7794 tgid:7794 ppid:5812 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:check_kcov_mode kernel/kcov.c:185 [inline] RIP: 0010:write_comp_data+0x3c/0x90 kernel/kcov.c:246 Code: 8b 05 a8 20 e9 11 a9 00 01 ff 00 74 1d f6 c4 01 74 67 a9 00 00 0f 00 75 60 a9 00 00 f0 00 75 59 8b 82 3c 16 00 00 85 c0 74 4f <8b> 82 18 16 00 00 83 f8 03 75 44 48 8b 82 20 16 00 00 8b 92 1c 16 RSP: 0000:ffffc900040f78c0 EFLAGS: 00000246 RAX: 0000000080000000 RBX: ffffc900040f7b48 RCX: ffffffff8b6b48d4 RDX: ffff888026cf4880 RSI: 0000000000000002 RDI: 0000000000000007 RBP: ffff888023d49082 R08: 0000000000000007 R09: 0000000000000002 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000060 R13: ffffc900040f7b60 R14: 0000000000000002 R15: ffffffff81f2cbc0 xa_is_node include/linux/xarray.h:1264 [inline] xas_start+0x104/0x790 lib/xarray.c:192 xas_load+0x22/0x5b0 lib/xarray.c:239 xas_find+0x573/0x890 lib/xarray.c:1406 xas_next_entry+0x267/0x3c0 include/linux/xarray.h:1727 next_uptodate_folio+0x29/0x4a0 mm/filemap.c:3553 filemap_map_pages+0x1bf/0x1680 mm/filemap.c:3705 do_fault_around mm/memory.c:5476 [inline] do_read_fault mm/memory.c:5509 [inline] do_fault mm/memory.c:5652 [inline] do_pte_missing+0xf1d/0x3fb0 mm/memory.c:4160 handle_pte_fault mm/memory.c:5997 [inline] __handle_mm_fault+0x103d/0x2a40 mm/memory.c:6140 handle_mm_fault+0x3fe/0xad0 mm/memory.c:6309 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1337 handle_page_fault arch/x86/mm/fault.c:1480 [inline] exc_page_fault+0x5c/0xc0 arch/x86/mm/fault.c:1538 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623 RIP: 0033:0x7fb797865b1a RSP: 002b:00007ffdf2b7c940 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000030 RCX: 0000000000000001 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 00007ffdf2b7c97c R08: 0000000000000000 R09: 00007fb7986ed6c0 R10: 000055555f0c6500 R11: 00007fb7986ed6c0 R12: 0000000000000070 R13: 00000000000927c0 R14: 000000000002f7ee R15: 00007ffdf2b7c9d0 task:syz.1.575 state:R running task stack:29048 pid:7795 tgid:7792 ppid:6202 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7090 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_call_function_single+0x1a/0x20 arch/x86/include/asm/idtentry.h:709 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870 Code: 39 0c 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 52 07 ed 0e 0f 82 74 02 00 00 8b 35 ea 36 ed 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 39 0c 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90004107880 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3bfc00 RCX: 00000000ef9d33e4 RDX: 0000000000000000 RSI: ffffffff8dbbee13 RDI: ffffffff8bf4a2e0 RBP: 0000000000000002 R08: 0ac0d5affe09d4ff R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_noprof+0x1cb/0x3b0 mm/slub.c:4203 getname_flags.part.0+0x4c/0x550 fs/namei.c:146 getname_flags+0x93/0xf0 include/linux/audit.h:322 getname include/linux/fs.h:2852 [inline] do_sys_openat2+0xb8/0x1d0 fs/open.c:1423 do_sys_open fs/open.c:1444 [inline] __do_sys_openat fs/open.c:1460 [inline] __se_sys_openat fs/open.c:1455 [inline] __x64_sys_openat+0x174/0x210 fs/open.c:1455 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f659dd8d2d0 RSP: 002b:00007f659ec67f10 EFLAGS: 00000293 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f659dd8d2d0 RDX: 0000000000000002 RSI: 00007f659ec67fa0 RDI: 00000000ffffff9c RBP: 00007f659ec67fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f659dfb6080 R15: 00007ffca3f58008 rcu: rcu_preempt kthread starved for 10330 jiffies! g17557 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:28704 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x116f/0x5de0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:6860 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xb00 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x270/0x380 kernel/rcu/tree.c:2248 kthread+0x3c2/0x780 kernel/kthread.c:464 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Not tainted 6.15.0-rc7-syzkaller-00099-g94305e83eccb #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:lock_acquire+0x62/0x350 kernel/locking/lockdep.c:5870 Code: 39 0c 12 83 f8 07 0f 87 bc 02 00 00 89 c0 48 0f a3 05 52 07 ed 0e 0f 82 74 02 00 00 8b 35 ea 36 ed 0e 85 f6 0f 85 8d 00 00 00 <48> 8b 44 24 30 65 48 2b 05 29 39 0c 12 0f 85 c7 02 00 00 48 83 c4 RSP: 0018:ffffc90000a08530 EFLAGS: 00000206 RAX: 0000000000000046 RBX: ffffffff8e3bfc00 RCX: 000000009a8d1b5c RDX: 0000000000000000 RSI: ffffffff8dbbee13 RDI: ffffffff8bf4a2e0 RBP: 0000000000000002 R08: 84dce478024d994f R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124ada000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff6ac156166 CR3: 000000001ea97000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xd1/0x20a0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47 kasan_save_track+0x14/0x30 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4147 [inline] slab_alloc_node mm/slub.c:4196 [inline] kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4248 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:658 skb_copy+0x1c9/0x3a0 net/core/skbuff.c:2131 mac80211_hwsim_tx_frame_no_nl.isra.0+0xb6b/0x1310 drivers/net/wireless/virtual/mac80211_hwsim.c:1866 mac80211_hwsim_tx_frame+0x1f1/0x2a0 drivers/net/wireless/virtual/mac80211_hwsim.c:2217 __mac80211_hwsim_beacon_tx drivers/net/wireless/virtual/mac80211_hwsim.c:2234 [inline] mac80211_hwsim_beacon_tx+0x595/0xa40 drivers/net/wireless/virtual/mac80211_hwsim.c:2317 __iterate_interfaces+0x2e2/0x650 net/mac80211/util.c:761 ieee80211_iterate_active_interfaces_atomic+0x71/0x1b0 net/mac80211/util.c:797 mac80211_hwsim_beacon+0x105/0x200 drivers/net/wireless/virtual/mac80211_hwsim.c:2347 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1825 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1842 handle_softirqs+0x216/0x8e0 kernel/softirq.c:579 __do_softirq kernel/softirq.c:613 [inline] invoke_softirq kernel/softirq.c:453 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:680 irq_exit_rcu+0x9/0x30 kernel/softirq.c:696 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:81 Code: f5 61 02 e9 53 fc 02 00 0f 1f 00 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 33 c0 1c 00 fb f4 cc cc cc cc 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197df8 EFLAGS: 000002c6 RAX: 0000000000913bad RBX: 0000000000000001 RCX: ffffffff8b6d3419 RDX: 0000000000000000 RSI: ffffffff8dbe4425 RDI: ffffffff8bf4a2e0 RBP: ffffed1003b5d488 R08: 0000000000000001 R09: ffffed10170a65bd R10: ffff8880b8532deb R11: 0000000000000000 R12: 0000000000000001 R13: ffff88801daea440 R14: ffffffff90852e10 R15: 0000000000000000 arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x6d/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x391/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:423 start_secondary+0x21d/0x2b0 arch/x86/kernel/smpboot.c:315 common_startup_64+0x13e/0x148 sched: DL replenish lagged too much hrtimer: interrupt took 1977182404 ns