rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=00d4/1/0x4000000000000000 softirq=27813/27814 fqs=1 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7955/1:b..l P7959/1:b..l rcu: (detected by 0, t=10502 jiffies, g=20537, q=472 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 7961 Comm: syz.3.642 Not tainted 6.14.0-next-20250402-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:check_preemption_disabled+0x43/0x120 lib/smp_processor_id.c:55 Code: 48 89 44 24 08 65 8b 1d 7f 4e 38 07 65 8b 05 74 4e 38 07 a9 ff ff ff 7f 74 24 65 49 8b 04 24 48 3b 44 24 08 0f 85 cc 00 00 00 <89> d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f c3 cc cc cc cc 48 c7 RSP: 0018:ffffc90000a08ac0 EFLAGS: 00000046 RAX: 027748e3299ffa00 RBX: 0000000000000001 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e770652 RDI: ffffffff8ca1db40 RBP: ffffffff9368d020 R08: 0000000000000001 R09: 0000000000000000 R10: ffffc90000a08c60 R11: fffff5200014118e R12: ffffffff9368d020 R13: 0000000000000000 R14: 0000000000000046 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888125093000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001700 CR3: 0000000059324000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:467 [inline] lock_acquire+0xdb/0x2f0 kernel/locking/lockdep.c:5865 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0xd8/0x130 kernel/locking/spinlock.c:162 debug_object_deactivate+0x164/0x390 lib/debugobjects.c:873 debug_hrtimer_deactivate kernel/time/hrtimer.c:450 [inline] debug_deactivate+0x1b/0x220 kernel/time/hrtimer.c:492 __run_hrtimer kernel/time/hrtimer.c:1759 [inline] __hrtimer_run_queues+0x310/0xd40 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:kasan_check_range+0x4/0x2a0 mm/kasan/generic.c:188 Code: 52 8e e8 7f 38 e2 ff 90 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 <55> 41 57 41 56 41 54 53 b0 01 48 85 f6 0f 84 a0 01 00 00 4c 8d 04 RSP: 0018:ffffc9000bc0f190 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff821a3c3c RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffea0001886870 RBP: dffffc0000000000 R08: ffffffff821a3c24 R09: 1ffffd4000310d08 R10: dffffc0000000000 R11: fffff94000310d09 R12: ffffea0001886840 R13: ffffea0001886840 R14: 0000000000000001 R15: ffff88807c1b7000 instrument_atomic_read_write include/linux/instrumented.h:96 [inline] atomic_add_negative include/linux/atomic/atomic-instrumented.h:1420 [inline] __folio_remove_rmap mm/rmap.c:1699 [inline] folio_remove_rmap_ptes+0xcc/0xa70 mm/rmap.c:1804 zap_present_folio_ptes mm/memory.c:1525 [inline] zap_present_ptes mm/memory.c:1586 [inline] do_zap_pte_range mm/memory.c:1687 [inline] zap_pte_range mm/memory.c:1731 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x21cf/0x44d0 mm/memory.c:1894 unmap_vmas+0x3ce/0x5f0 mm/memory.c:1984 exit_mmap+0x2bc/0xde0 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:586 do_exit+0x994/0x28c0 kernel/exit.c:941 do_group_exit+0x207/0x2c0 kernel/exit.c:1103 get_signal+0x1696/0x1730 kernel/signal.c:3036 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f821238d169 Code: Unable to access opcode bytes at 0x7f821238d13f. RSP: 002b:00007f82131250e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f82125a5fa8 RCX: 00007f821238d169 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f82125a5fac RBP: 00007f82125a5fa0 R08: 7fffffffffffffff R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007f82125a5fac R13: 0000000000000000 R14: 00007ffdaaaceeb0 R15: 00007ffdaaacef98 task:syz.1.641 state:R running task stack:24168 pid:7959 tgid:7958 ppid:5853 task_flags:0x40054c flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6947 preempt_schedule+0xe4/0xf0 kernel/sched/core.c:6971 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+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] zap_pte_range mm/memory.c:1761 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x39c5/0x44d0 mm/memory.c:1894 unmap_vmas+0x3ce/0x5f0 mm/memory.c:1984 exit_mmap+0x2bc/0xde0 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:586 do_exit+0x994/0x28c0 kernel/exit.c:941 do_group_exit+0x207/0x2c0 kernel/exit.c:1103 get_signal+0x1696/0x1730 kernel/signal.c:3036 arch_do_signal_or_restart+0x98/0x840 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x230 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fbc9558d169 RSP: 002b:00007fbc933f60e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007fbc957a5fa8 RCX: 00007fbc9558d169 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007fbc957a5fac RBP: 00007fbc957a5fa0 R08: 7fffffffffffffff R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 00007fbc957a5fac R13: 0000000000000000 R14: 00007ffe64b9ff40 R15: 00007ffe64ba0028 task:syz.4.638 state:R running task stack:26048 pid:7955 tgid:7954 ppid:5841 task_flags:0x400040 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 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:__module_address+0x6/0x390 kernel/module/main.c:3710 Code: e8 0f 18 80 00 e9 3f ff ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 41 57 <41> 56 41 55 41 54 53 48 39 3d bc bb f3 0c 0f 87 6b 02 00 00 49 89 RSP: 0018:ffffc9000bbdede8 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 00007f5ff878bc1f RCX: ffff88807a091e00 RDX: 0000000000000000 RSI: ffffffff8ca1db20 RDI: 00007f5ff878bc1f RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff88807a091e00 R13: ffffffff81aee520 R14: ffffffff81ad5aad R15: 00007f5ff878bc1f __module_text_address kernel/module/main.c:3769 [inline] is_module_text_address+0x89/0x1f0 kernel/module/main.c:3744 kernel_text_address+0x96/0xe0 kernel/extable.c:119 __kernel_text_address+0xd/0x40 kernel/extable.c:79 unwind_get_return_address+0x4d/0x90 arch/x86/kernel/unwind_orc.c:369 arch_stack_walk+0xff/0x150 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x11a/0x1d0 kernel/stacktrace.c:122 save_stack+0xfc/0x1f0 mm/page_owner.c:156 __set_page_owner+0x93/0x530 mm/page_owner.c:329 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1717 prep_new_page mm/page_alloc.c:1725 [inline] get_page_from_freelist+0x352b/0x36c0 mm/page_alloc.c:3652 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4934 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2301 folio_alloc_mpol_noprof+0x36/0x70 mm/mempolicy.c:2320 shmem_alloc_folio mm/shmem.c:1854 [inline] shmem_alloc_and_add_folio+0x490/0x1070 mm/shmem.c:1893 shmem_get_folio_gfp+0x655/0x1800 mm/shmem.c:2533 shmem_get_folio mm/shmem.c:2639 [inline] shmem_write_begin+0x17e/0x3a0 mm/shmem.c:3289 generic_perform_write+0x329/0xa10 mm/filemap.c:4102 shmem_file_write_iter+0xf9/0x120 mm/shmem.c:3464 new_sync_write fs/read_write.c:591 [inline] vfs_write+0x70f/0xd10 fs/read_write.c:684 ksys_write+0x19d/0x2d0 fs/read_write.c:736 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: 0033:0x7f5ff878bc1f RSP: 002b:00007f5ff9696df0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000001000000 RCX: 00007f5ff878bc1f RDX: 0000000001000000 RSI: 00007f5fee000000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000009688 R10: 000020000001c302 R11: 0000000000000293 R12: 0000000000000003 R13: 00007f5ff9696ef0 R14: 00007f5ff9696eb0 R15: 00007f5fee000000 rcu: rcu_preempt kthread starved for 10495 jiffies! g20537 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:26376 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 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: 7306 Comm: syz-executor Not tainted 6.14.0-next-20250402-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 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 48 e8 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 f8 e3 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:ffffc9000bb7f4c0 EFLAGS: 00000293 RAX: ffffffff81b7732d RBX: 1ffff110170e7e91 RCX: ffff88802fd31e00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000bb7f6c0 R08: ffffffff81b772f8 R09: 1ffffffff20bfe26 R10: dffffc0000000000 R11: fffffbfff20bfe27 R12: ffff8880b863ad08 R13: ffff8880b873f488 R14: ffff8880b863ad00 R15: 0000000000000001 FS: 00005555709dc500(0000) GS:ffff888124f93000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f86c5cd56c0 CR3: 0000000066c4c000 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 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1275 [inline] flush_tlb_mm_range+0xb8d/0x13f0 arch/x86/mm/tlb.c:1365 dup_mmap kernel/fork.c:765 [inline] dup_mm kernel/fork.c:1734 [inline] copy_mm+0x19de/0x22c0 kernel/fork.c:1786 copy_process+0x17de/0x3d10 kernel/fork.c:2429 kernel_clone+0x242/0x930 kernel/fork.c:2844 __do_sys_clone kernel/fork.c:2987 [inline] __se_sys_clone kernel/fork.c:2971 [inline] __x64_sys_clone+0x268/0x2e0 kernel/fork.c:2971 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: 0033:0x7f86c4f839d3 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffd8918f698 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f86c4f839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555709dc7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000025e10 R15: 00007ffd8918f830