rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=fe84/1/0x4000000000000000 softirq=418966/418967 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P11248/1:b..l P19248/1:b..l P19250/1:b..l rcu: (detected by 1, t=10505 jiffies, g=332225, q=194 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 19251 Comm: syz.6.11466 Not tainted 6.17.0-rc1-syzkaller-00199-gdfd4b508c8c6 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:srso_alias_safe_ret+0x0/0x7 arch/x86/lib/retpoline.S:172 Code: cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc cc <48> 8d 64 24 08 c3 cc e8 f4 ff ff ff 0f 0b cc cc cc cc cc cc cc cc RSP: 0018:ffffc90000007b90 EFLAGS: 00000086 RAX: 0000000000000000 RBX: 0000000000000000 RCX: 5425711197656d00 RDX: 0000000000000000 RSI: ffffffff8be334e0 RDI: ffffffff8be334a0 RBP: ffffffff899a81b4 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffffff899a80f0 R12: 0000000000000000 R13: ffff888023c0e300 R14: 0000000000000000 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fea75ae56c0 CR3: 00000000a53bb000 CR4: 0000000000350ef0 Call Trace: srso_alias_return_thunk+0x5/0xfbef5 arch/x86/lib/retpoline.S:182 rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:751 trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0x5f/0x360 kernel/locking/lockdep.c:5831 __raw_spin_lock include/linux/spinlock_api_smp.h:133 [inline] _raw_spin_lock+0x2e/0x40 kernel/locking/spinlock.c:154 spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:929 __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: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 64 49 fe 0b 48 89 de 5b e9 73 98 58 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 50 a0 92 65 8b 15 88 a4 e0 10 81 e2 00 01 ff 00 RSP: 0018:ffffc9000c38f508 EFLAGS: 00000246 RAX: ffffffff8211c0c6 RBX: ffffea000176aec0 RCX: 0000000000000000 RDX: 0000000000000001 RSI: ffffea000176aec0 RDI: ffffea000176aec0 RBP: 0000000000000001 R08: ffffea000176aec7 R09: 1ffffd40002ed5d8 R10: dffffc0000000000 R11: fffff940002ed5d9 R12: ffffea000176aec0 R13: dffffc0000000000 R14: 800000005dabb000 R15: ffffea000176aec0 __folio_rmap_sanity_checks+0x26/0x7d0 include/linux/rmap.h:409 __folio_remove_rmap mm/rmap.c:1694 [inline] folio_remove_rmap_ptes+0x3b/0xaf0 mm/rmap.c:1804 zap_present_folio_ptes mm/memory.c:1523 [inline] zap_present_ptes mm/memory.c:1581 [inline] do_zap_pte_range mm/memory.c:1682 [inline] zap_pte_range mm/memory.c:1726 [inline] zap_pmd_range mm/memory.c:1818 [inline] zap_pud_range mm/memory.c:1847 [inline] zap_p4d_range mm/memory.c:1868 [inline] unmap_page_range+0x1f7f/0x4370 mm/memory.c:1889 unmap_single_vma mm/memory.c:1932 [inline] unmap_vmas+0x399/0x580 mm/memory.c:1976 exit_mmap+0x248/0xb50 mm/mmap.c:1280 __mmput+0x118/0x420 kernel/fork.c:1130 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:949 do_group_exit+0x21c/0x2d0 kernel/exit.c:1102 __do_sys_exit_group kernel/exit.c:1113 [inline] __se_sys_exit_group kernel/exit.c:1111 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1111 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f975c78ebe9 Code: Unable to access opcode bytes at 0x7f975c78ebbf. RSP: 002b:00007ffc3d6f3c68 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f975c78ebe9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffc3d6f3ccc R08: 000000033d6f3d5f R09: 00000000000927c0 R10: 0000000000000001 R11: 0000000000000246 R12: 0000000000000191 R13: 00000000000927c0 R14: 000000000031cfa3 R15: 00007ffc3d6f3d20 task:syz.3.11463 state:R running task stack:25256 pid:19250 tgid:19249 ppid:8061 task_flags:0x400040 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7288 irqentry_exit+0x6f/0x90 kernel/entry/common.c:197 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:trace_lock_release include/trace/events/lock.h:69 [inline] RIP: 0010:lock_release+0x4d/0x3e0 kernel/locking/lockdep.c:5879 Code: 24 28 0f 1f 44 00 00 65 8b 05 13 e4 02 11 83 f8 08 0f 83 9a 02 00 00 89 c0 48 0f a3 05 fc 14 06 0e 73 16 e8 45 f1 08 00 84 c0 <75> 0d f6 05 1e fb ef 0d 01 0f 84 ad 02 00 00 83 3d 1d 46 06 0e 00 RSP: 0018:ffffc9000bb76f70 EFLAGS: 00000202 RAX: 0000000000000001 RBX: ffffffff90325e01 RCX: abd78149dc48fd00 RDX: ffffc9000bb77101 RSI: ffffffff8be334e0 RDI: ffffffff8be334a0 RBP: dffffc0000000000 R08: ffffc9000bb77190 R09: ffffc9000bb77158 R10: dffffc0000000000 R11: fffff5200176ee2d R12: ffffc9000bb771a0 R13: ffffffff8172c195 R14: ffffffff8e139ee0 R15: ffffffff8172c195 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 __unwind_start+0x5b9/0x760 arch/x86/kernel/unwind_orc.c:758 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 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2435 shmem_alloc_folio mm/shmem.c:1908 [inline] shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1947 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2597 shmem_get_folio mm/shmem.c:2703 [inline] shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3353 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 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: 0033:0x7f98c7d8d69f RSP: 002b:00007f98c5feddf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f98c7d8d69f RDX: 0000000001000000 RSI: 00007f98bda00000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000037f5e R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f98c5fedef0 R14: 00007f98c5fedeb0 R15: 00007f98bda00000 task:syz.1.11462 state:R running task stack:25256 pid:19248 tgid:19247 ppid:19006 task_flags:0x400040 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7238 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:871 [inline] class_rcu_destructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __set_page_owner+0x8d/0x4a0 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851 prep_new_page mm/page_alloc.c:1859 [inline] get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3858 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416 folio_alloc_mpol_noprof+0x39/0x70 mm/mempolicy.c:2435 shmem_alloc_folio mm/shmem.c:1908 [inline] shmem_alloc_and_add_folio+0x447/0xf60 mm/shmem.c:1947 shmem_get_folio_gfp+0x59d/0x1660 mm/shmem.c:2597 shmem_get_folio mm/shmem.c:2703 [inline] shmem_write_begin+0xf7/0x2b0 mm/shmem.c:3353 generic_perform_write+0x2c5/0x900 mm/filemap.c:4175 shmem_file_write_iter+0xf8/0x120 mm/shmem.c:3528 new_sync_write fs/read_write.c:593 [inline] vfs_write+0x5c9/0xb30 fs/read_write.c:686 ksys_write+0x145/0x250 fs/read_write.c:738 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: 0033:0x7fdcd018d69f RSP: 002b:00007fdcd10c5df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007fdcd018d69f RDX: 0000000001000000 RSI: 00007fdcc5e00000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000005a9d R10: 0000000000000002 R11: 0000000000000293 R12: 0000000000000003 R13: 00007fdcd10c5ef0 R14: 00007fdcd10c5eb0 R15: 00007fdcc5e00000 task:syz-executor state:R running task stack:17248 pid:11248 tgid:11248 ppid:11229 task_flags:0x400140 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7145 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7169 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] copy_pte_range mm/memory.c:1201 [inline] copy_pmd_range+0x68c6/0x71d0 mm/memory.c:1261 copy_pud_range mm/memory.c:1298 [inline] copy_p4d_range mm/memory.c:1322 [inline] copy_page_range+0xc14/0x1270 mm/memory.c:1410 dup_mmap+0xf57/0x1ac0 mm/mmap.c:1834 dup_mm kernel/fork.c:1485 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1537 copy_process+0x1706/0x3c00 kernel/fork.c:2175 kernel_clone+0x21e/0x840 kernel/fork.c:2605 __do_sys_clone kernel/fork.c:2748 [inline] __se_sys_clone kernel/fork.c:2732 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2732 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: 0033:0x7fea74d85453 RSP: 002b:00007ffd0a38d558 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fea74d85453 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 0000555563ea67d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000031cff3 R15: 00007ffd0a38d6f0 rcu: rcu_preempt kthread starved for 10505 jiffies! g332225 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:26888 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+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: 1 UID: 0 PID: 18698 Comm: kworker/u8:16 Not tainted 6.17.0-rc1-syzkaller-00199-gdfd4b508c8c6 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877 Code: 89 ee 83 e6 01 31 ff e8 b6 62 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 5e 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 45 5e 0b 00 eb e4 44 RSP: 0018:ffffc9000c6b7660 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170c8341 RCX: ffff8880384f0000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000c6b77e0 R08: ffffffff8fa38137 R09: 1ffffffff1f47026 R10: dffffc0000000000 R11: fffffbfff1f47027 R12: ffff8880b8641a08 R13: dffffc0000000000 R14: ffff8880b873b1c0 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125d1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000003200 CR3: 000000000df36000 CR4: 0000000000350ef0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 ip6_tunnel: ip6tnl1 xmit: Local address not yet configured!