rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=72bc/1/0x4000000000000000 softirq=22292/22301 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6520/1:b..l rcu: (detected by 0, t=10502 jiffies, g=15373, q=845 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6516 Comm: modprobe Not tainted 6.14.0-syzkaller-13408-g9f867ba24d36 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:__lock_acquire+0x9f/0xd80 kernel/locking/lockdep.c:5136 Code: 44 89 c3 45 89 cd e8 a0 f0 ff ff 45 89 e9 45 31 ed 41 89 d8 48 85 c0 0f 84 85 0a 00 00 8b bd e8 0a 00 00 83 3d e1 a4 d1 18 00 <75> 09 83 ff 30 0f 83 f4 00 00 00 8b 94 24 98 00 00 00 8b 9c 24 88 RSP: 0018:ffffc90000a08b50 EFLAGS: 00000046 RAX: ffffffff940dfc38 RBX: ffffffff8ed3dfe0 RCX: 0000000000000001 RDX: ffffffff9428f6c0 RSI: 0000000000000000 RDI: 0000000000000001 RBP: ffff888026678000 R08: 0000000000000000 R09: 0000000000000001 R10: dffffc0000000000 R11: ffffed100f74905e R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: ffffffff8ed3dfe0 FS: 0000000000000000(0000) GS:ffff8881250c9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f2e4e242440 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_acquire+0x116/0x2f0 kernel/locking/lockdep.c:5866 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] advance_sched+0xa1e/0xca0 net/sched/sch_taprio.c:985 __run_hrtimer kernel/time/hrtimer.c:1791 [inline] __hrtimer_run_queues+0x5a6/0xd40 kernel/time/hrtimer.c:1855 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1917 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_release+0x244/0x3e0 arch/x86/include/asm/irqflags.h:-1 Code: 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 0f 85 c3 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 03 <48> 3b 44 24 28 0f 85 82 01 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc900038df0a0 EFLAGS: 00000206 RAX: 8a77c1ccf452cd00 RBX: ffffffff93657020 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8e4ea0a8 RDI: ffffffff8ca0e220 RBP: ffff888026678b18 R08: ffffc900038df948 R09: 0000000000000000 R10: ffffc900038df230 R11: fffff5200071be48 R12: 0000000000000001 R13: ffff888026678000 R14: 0000000000000206 R15: ffffffff8ed3dfe0 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+0x1a9f/0x23b0 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x1e0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1262 [inline] free_unref_folios+0xdfd/0x17e0 mm/page_alloc.c:2737 folios_put_refs+0x70a/0x800 mm/swap.c:992 free_pages_and_swap_cache+0x2ea/0x6a0 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+0x3a9/0x690 mm/mmu_gather.c:404 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:496 exit_mmap+0x5b1/0xde0 mm/mmap.c:1297 __mmput+0x115/0x410 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 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+0x26c3/0x26d0 arch/x86/include/generated/asm/syscalls_64.h:232 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2e4e300a90 Code: Unable to access opcode bytes at 0x7f2e4e300a66. RSP: 002b:00007ffe62114ab8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 00007f2e4e3f1860 RCX: 00007f2e4e300a90 RDX: 00000000000000e7 RSI: 000000000000003c RDI: 0000000000000001 RBP: 00007f2e4e3f1860 R08: 00007ffe62114930 R09: 00007ffe62114a10 R10: 00007ffe62114970 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007f2e4e3f5658 R15: 0000000000000001 task:dhcpcd-run-hook state:R running task stack:25896 pid:6520 tgid:6520 ppid:6519 task_flags:0x400040 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 preempt_schedule_irq+0xfe/0x1c0 kernel/sched/core.c:7090 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:kasan_check_range+0x1ba/0x2a0 mm/kasan/generic.c:189 Code: fb 48 8d 5d 07 48 85 ed 48 0f 49 dd 48 83 e3 f8 48 29 dd 74 12 41 80 3b 00 0f 85 b3 00 00 00 49 ff c3 48 ff cd 75 ee 5b 41 5c <41> 5e 41 5f 5d c3 cc cc cc cc 40 84 ed 75 61 f7 c5 00 ff 00 00 75 RSP: 0018:ffffc900038aef68 EFLAGS: 00000256 RAX: ffffc900038af501 RBX: 0000000000000010 RCX: ffffffff816df656 RDX: 0000000000000001 RSI: 0000000000000010 RDI: ffffc900038af0d0 RBP: 0000000000000000 R08: ffffc900038af0df R09: 1ffff92000715e1b R10: dffffc0000000000 R11: fffff52000715e1c R12: ffffc900038af080 R13: ffffc900038b0000 R14: dffffc0000000001 R15: fffff52000715e1c __asan_memset+0x23/0x50 mm/kasan/shadow.c:84 unwind_next_frame+0xb46/0x23b0 arch/x86/kernel/unwind_orc.c:592 arch_stack_walk+0x11e/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:576 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2389 [inline] slab_free mm/slub.c:4646 [inline] kmem_cache_free+0x197/0x410 mm/slub.c:4748 anon_vma_chain_free mm/rmap.c:147 [inline] unlink_anon_vmas+0x297/0x5f0 mm/rmap.c:421 free_pgtables+0x44e/0x6f0 mm/memory.c:391 exit_mmap+0x5a9/0xde0 mm/mmap.c:1295 __mmput+0x115/0x410 kernel/fork.c:1379 exec_mmap+0x791/0x880 fs/exec.c:1009 begin_new_exec+0x12f0/0x2150 fs/exec.c:1264 load_elf_binary+0x9a2/0x28a0 fs/binfmt_elf.c:1001 search_binary_handler fs/exec.c:1778 [inline] exec_binprm fs/exec.c:1810 [inline] bprm_execve+0x95b/0x1390 fs/exec.c:1862 do_execveat_common+0x57c/0x710 fs/exec.c:1967 do_execve fs/exec.c:2041 [inline] __do_sys_execve fs/exec.c:2117 [inline] __se_sys_execve fs/exec.c:2112 [inline] __x64_sys_execve+0x94/0xb0 fs/exec.c:2112 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ecd9c1ef7 RSP: 002b:00007ffd21672b98 EFLAGS: 00000246 ORIG_RAX: 000000000000003b RAX: ffffffffffffffda RBX: 000055fe69f04ec0 RCX: 00007f4ecd9c1ef7 RDX: 000055fe69f04f08 RSI: 000055fe69f04ec0 RDI: 000055fe69f04f98 RBP: 000055fe69f04f98 R08: 000055fe69f04f9d R09: 00007ffd21677e9a R10: 00007f4ecdbc2088 R11: 0000000000000246 R12: 000055fe69f04f08 R13: 00007f4ecdb6f904 R14: 000055fe69f04f08 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10498 jiffies! g15373 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:26688 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b33/0x51f0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/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: 0 UID: 0 PID: 3018 Comm: kworker/u8:8 Not tainted 6.14.0-syzkaller-13408-g9f867ba24d36 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bac/0x2d40 kernel/smp.c:885 Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 b8 e2 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 68 de 0b 00 eb 41 f3 90 <48> b8 00 00 00 00 00 fc ff df 0f b6 04 03 84 c0 75 11 41 f7 45 00 RSP: 0018:ffffc9000be17640 EFLAGS: 00000293 RAX: ffffffff81b7683d RBX: 1ffff110170e7e61 RCX: ffff8880303b9e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000be17840 R08: ffffffff81b76808 R09: 1ffffffff20bd6ce R10: dffffc0000000000 R11: fffffbfff20bd6cf R12: ffff8880b863ab88 R13: ffff8880b873f308 R14: ffff8880b863ab80 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124fc9000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fb30c1c5f98 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:2455 [inline] text_poke_bp_batch+0x354/0xb30 arch/x86/kernel/alternative.c:2665 text_poke_flush arch/x86/kernel/alternative.c:2856 [inline] text_poke_finish+0x30/0x50 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x136/0x260 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xc0/0x250 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3238 [inline] process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319 worker_thread+0x870/0xd50 kernel/workqueue.c:3400 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245