rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=d58c/1/0x4000000000000000 softirq=72477/72478 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11941/1:b..l rcu: (detected by 0, t=10506 jiffies, g=52393, q=458 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6415 Comm: udevd Not tainted 6.16.0-rc7-syzkaller-00034-g25fae0b93d1d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:__raw_spin_lock include/linux/spinlock_api_smp.h:134 [inline] RIP: 0010:_raw_spin_lock+0x36/0x40 kernel/locking/spinlock.c:154 Code: 00 e8 1e bf 20 f6 48 8d 7b 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 74 24 08 e8 72 17 2e f6 48 83 c4 08 48 89 df 5b c5 bb 2e f6 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc90000a08c68 EFLAGS: 00000096 RAX: a934157c14898400 RBX: ffff88806d30c036 RCX: a934157c14898400 RDX: 0000000000000000 RSI: ffffffff8db84602 RDI: ffff8880561712e8 RBP: 0000000000000002 R08: 0000000000000000 R09: ffffffff898d5f54 R10: dffffc0000000000 R11: ffffffff898d5e90 R12: ffff888056171340 R13: ffff888056171000 R14: dffffc0000000000 R15: ffff88802a960ad8 FS: 00007fdabbbf3880(0000) GS:ffff888125d23000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc0785edee8 CR3: 00000000683c8000 CR4: 0000000000350ef0 Call Trace: spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:924 __run_hrtimer kernel/time/hrtimer.c:1761 [inline] __hrtimer_run_queues+0x52c/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:bytes_is_nonzero mm/kasan/generic.c:87 [inline] RIP: 0010:memory_is_nonzero mm/kasan/generic.c:104 [inline] RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline] RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline] RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline] RIP: 0010:kasan_check_range+0x9f/0x2c0 mm/kasan/generic.c:189 Code: 00 fc ff df 4d 8d 34 19 4d 89 f4 4d 29 dc 49 83 fc 10 7f 29 4d 85 e4 0f 84 41 01 00 00 4c 89 cb 48 f7 d3 4c 01 fb 41 80 3b 00 <0f> 85 de 01 00 00 49 ff c3 48 ff c3 75 ee e9 21 01 00 00 44 89 dd RSP: 0018:ffffc9001d387070 EFLAGS: 00000246 RAX: ffff88802a960001 RBX: ffffffffffffffff RCX: ffffffff8172d2c6 RDX: 0000000000000001 RSI: 0000000000000060 RDI: ffffc9001d387128 RBP: 0000000000000000 R08: ffffc9001d387187 R09: 1ffff92003a70e30 R10: dffffc0000000000 R11: fffff52003a70e30 R12: 000000000000000c R13: ffff88802a960000 R14: fffff52003a70e31 R15: 1ffff92003a70e25 __asan_memset+0x22/0x50 mm/kasan/shadow.c:84 __unwind_start+0x36/0x760 arch/x86/kernel/unwind_orc.c:686 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 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] free_unref_folios+0xc66/0x14d0 mm/page_alloc.c:2763 folios_put_refs+0x559/0x640 mm/swap.c:992 free_pages_and_swap_cache+0x4be/0x520 mm/swap_state.c:267 __tlb_batch_free_encoded_pages mm/mmu_gather.c:136 [inline] tlb_batch_pages_flush mm/mmu_gather.c:149 [inline] tlb_flush_mmu_free mm/mmu_gather.c:397 [inline] tlb_flush_mmu+0x3a0/0x680 mm/mmu_gather.c:404 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497 vms_clear_ptes+0x42c/0x540 mm/vma.c:1230 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1272 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1531 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1579 __vm_munmap+0x23b/0x3d0 mm/vma.c:3108 __do_sys_munmap mm/mmap.c:1084 [inline] __se_sys_munmap mm/mmap.c:1081 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fdabb51e097 Code: 73 01 c3 48 8b 0d 61 2d 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 31 2d 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffd4b1a4168 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 000055857745f8d0 RCX: 00007fdabb51e097 RDX: 000055857744c428 RSI: 0000000000000200 RDI: 00007fdabbbeb000 RBP: 0000000000000008 R08: 00005585774587a0 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000246 R12: 000055857744b0d0 R13: 00007fdabbd1a39c R14: 0000000000001000 R15: 0000000000000008 task:syz.5.1333 state:R running task stack:25096 pid:11941 tgid:11941 ppid:5852 task_flags:0x400040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7109 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_reschedule_ipi+0x1a/0x20 arch/x86/include/asm/idtentry.h:707 RIP: 0010:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5875 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 6b 94 01 11 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000ba2f278 EFLAGS: 00000206 RAX: 8ef31c7f8a3b9700 RBX: 0000000000000000 RCX: 8ef31c7f8a3b9700 RDX: 0000000000000000 RSI: ffffffff8db84602 RDI: ffffffff8be28d40 RBP: ffffffff8172aae5 R08: 0000000000000000 R09: ffffffff8172aae5 R10: dffffc0000000000 R11: ffffffff81acfe40 R12: 0000000000000002 R13: ffffffff8e13f0e0 R14: 0000000000000000 R15: 0000000000000246 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+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 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:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204 vm_area_dup+0x2b/0x680 mm/vma_init.c:122 __split_vma+0x1a9/0xa00 mm/vma.c:512 split_vma mm/vma.c:595 [inline] vma_modify+0x12c3/0x1970 mm/vma.c:1618 vma_modify_flags+0x1e8/0x230 mm/vma.c:1644 mprotect_fixup+0x400/0x9b0 mm/mprotect.c:658 do_mprotect_pkey+0x8cd/0xce0 mm/mprotect.c:832 __do_sys_mprotect mm/mprotect.c:853 [inline] __se_sys_mprotect mm/mprotect.c:850 [inline] __x64_sys_mprotect+0x80/0x90 mm/mprotect.c:850 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f393a98ea67 RSP: 002b:00007ffe33ffb078 EFLAGS: 00000206 ORIG_RAX: 000000000000000a RAX: ffffffffffffffda RBX: 00007f393b80b6c0 RCX: 00007f393a98ea67 RDX: 0000000000000003 RSI: 0000000000020000 RDI: 00007f393b7ec000 RBP: 0000000000000000 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000021000 R11: 0000000000000206 R12: 00007ffe33ffb1d0 R13: ffffffffffffffc0 R14: 0000000000001000 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10506 jiffies! g52393 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 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5397 [inline] __schedule+0x16fd/0x4cf0 kernel/sched/core.c:6786 __schedule_loop kernel/sched/core.c:6864 [inline] schedule+0x165/0x360 kernel/sched/core.c:6879 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 11947 Comm: syz.2.1336 Not tainted 6.16.0-rc7-syzkaller-00034-g25fae0b93d1d #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0xf69/0x12d0 kernel/smp.c:885 Code: 00 45 8b 2f 44 89 ee 83 e6 01 31 ff e8 90 6e 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 3b 6a 0b 00 eb 37 f3 90 <43> 0f b6 04 2c 84 c0 75 10 41 f7 07 01 00 00 00 74 1e e8 20 6a 0b RSP: 0018:ffffc900036ff580 EFLAGS: 00000246 RAX: ffffffff81b4bcb0 RBX: ffff8880b863b1c0 RCX: 0000000000080000 RDX: ffffc900047b2000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc900036ff6e0 R08: ffffffff8fa1dcf7 R09: 1ffffffff1f43b9e R10: dffffc0000000000 R11: fffffbfff1f43b9f R12: 1ffff110170e7f5d R13: dffffc0000000000 R14: 0000000000000001 R15: ffff8880b873fae8 FS: 00007fa0ff2b26c0(0000) GS:ffff888125c23000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa0f3c3f000 CR3: 0000000051f2d000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline] flush_tlb_mm_range+0x6b1/0x12c0 arch/x86/mm/tlb.c:1451 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 vms_clear_ptes+0x42c/0x540 mm/vma.c:1230 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1272 do_vmi_align_munmap+0x358/0x420 mm/vma.c:1531 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1579 __vm_munmap+0x23b/0x3d0 mm/vma.c:3108 __do_sys_munmap mm/mmap.c:1084 [inline] __se_sys_munmap mm/mmap.c:1081 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fa0fe38ea37 Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 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:00007fa0ff2b1e18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007fa0fe38ea37 RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007fa0f3c00000 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000050e R10: 0000200000002082 R11: 0000000000000246 R12: 0000000000000006 R13: 00007fa0ff2b1ef0 R14: 00007fa0ff2b1eb0 R15: 00007fa0f3c00000