rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9047/1:b..l rcu: (detected by 0, t=10502 jiffies, g=39033, q=440 ncpus=2) task:syz.1.848 state:R running task stack:26184 pid:9047 tgid:9044 ppid:5616 task_flags:0x400040 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode_preempt include/linux/irq-entry-common.h:468 [inline] irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x205/0xa00 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:lock_acquire+0x5e/0x370 kernel/locking/lockdep.c:5872 Code: 05 3b 8d 7e 12 83 f8 07 0f 87 da 00 00 00 48 0f a3 05 c6 94 3c 0f 0f 82 ac 02 00 00 8b 35 8e c8 3c 0f 85 f6 0f 85 c7 00 00 00 <48> 8b 44 24 30 65 48 2b 05 dd 8c 7e 12 0f 85 ec 02 00 00 48 83 c4 RSP: 0018:ffffc9000369ef28 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffffffff8e182264 RDI: ffffffff8c402680 RBP: ffffffff8ebe8200 R08: 00000000d4ddbe60 R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] class_rcu_constructor include/linux/rcupdate.h:1183 [inline] unwind_next_frame+0xd1/0x2090 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xa44/0x1710 mm/page_alloc.c:3011 folios_put_refs+0x585/0xaa0 mm/swap.c:1057 folio_batch_release include/linux/folio_batch.h:101 [inline] mapping_try_invalidate+0x2ff/0x3c0 mm/truncate.c:579 drop_pagecache_sb+0x12e/0x3d0 fs/drop_caches.c:40 __iterate_supers+0x210/0x330 fs/super.c:867 drop_caches_sysctl_handler fs/drop_caches.c:64 [inline] drop_caches_sysctl_handler+0xeb/0x120 fs/drop_caches.c:51 proc_sys_call_handler+0x47f/0x5a0 fs/proc/proc_sysctl.c:600 iter_file_splice_write+0x830/0x10b0 fs/splice.c:736 do_splice_from fs/splice.c:936 [inline] direct_splice_actor+0x192/0x690 fs/splice.c:1159 splice_direct_to_actor+0x345/0xa30 fs/splice.c:1103 do_splice_direct_actor fs/splice.c:1202 [inline] do_splice_direct+0x174/0x240 fs/splice.c:1228 do_sendfile+0xadc/0xe20 fs/read_write.c:1371 __do_sys_sendfile64 fs/read_write.c:1426 [inline] __se_sys_sendfile64 fs/read_write.c:1418 [inline] __x64_sys_sendfile64+0x154/0x220 fs/read_write.c:1418 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4ae9f9e019 RSP: 002b:00007f4aeaea3028 EFLAGS: 00000246 ORIG_RAX: 0000000000000028 RAX: ffffffffffffffda RBX: 00007f4aea226090 RCX: 00007f4ae9f9e019 RDX: 0000200000002080 RSI: 0000000000000006 RDI: 0000000000000007 RBP: 00007f4aea03500c R08: 0000000000000000 R09: 0000000000000000 R10: 000000000000000c R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4aea226128 R14: 00007f4aea226090 R15: 00007ffd38978c68 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g39033 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=16838 rcu: rcu_preempt kthread starved for 10502 jiffies! g39033 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:27432 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0xdd/0x2c0 kernel/sched/core.c:7326 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2325 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x72b/0xd50 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 9179 Comm: syz.5.885 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 RIP: 0010:check_preemption_disabled+0x1a/0xe0 lib/smp_processor_id.c:16 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 54 55 53 48 83 ec 08 65 8b 1d d5 a5 a8 08 65 f7 05 c6 a5 a8 08 ff ff ff 7f <74> 0f 48 83 c4 08 89 d8 5b 5d 41 5c c3 cc cc cc cc 9c 58 f6 c4 02 RSP: 0018:ffffc90000a08de8 EFLAGS: 00000002 RAX: 00000000ffffffff RBX: 0000000000000001 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8e29e652 RDI: ffffffff8c402680 RBP: ffff8880472a2540 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: 00000000ffffffff R13: 0000000000000046 R14: 0000000000000001 R15: 0000000000000000 FS: 00007feb5e05c6c0(0000) GS:ffff888123ed8000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007feb5e03aff8 CR3: 00000000753b4000 CR4: 00000000003526f0 Call Trace: lockdep_recursion_inc kernel/locking/lockdep.c:465 [inline] lock_is_held_type+0x60/0x140 kernel/locking/lockdep.c:5939 lock_is_held include/linux/lockdep.h:249 [inline] __remove_hrtimer+0x374/0x440 kernel/time/hrtimer.c:1145 __run_hrtimer kernel/time/hrtimer.c:2012 [inline] __hrtimer_run_queues+0x352/0x9c0 kernel/time/hrtimer.c:2096 hrtimer_interrupt+0x3e5/0x940 kernel/time/hrtimer.c:2215 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1051 [inline] __sysvec_apic_timer_interrupt+0x109/0x470 arch/x86/kernel/apic/apic.c:1068 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1062 [inline] sysvec_apic_timer_interrupt+0x9e/0xc0 arch/x86/kernel/apic/apic.c:1062 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:__sanitizer_cov_trace_pc+0x2a/0x70 kernel/kcov.c:235 Code: f3 0f 1e fa 65 8b 05 45 1e 5a 12 48 8b 34 24 65 48 8b 15 21 1e 5a 12 a9 00 01 ff 00 74 1b f6 c4 01 74 07 a9 00 00 ff 00 74 05 d1 a0 b4 09 8b 82 24 17 00 00 85 c0 74 f1 8b 82 f8 16 00 00 83 RSP: 0018:ffffc9000567f9f8 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffffffff8c370cc0 RCX: ffffffff84dd6884 RDX: ffff8880472a2540 RSI: ffffffff84dfab1a RDI: ffffc9000567fc90 RBP: ffffc9000567fc28 R08: 0000000000000001 R09: 0000000000000003 R10: 0000000000000001 R11: 0000000000000000 R12: ffffc9000567fc90 R13: ffffc9000567fc90 R14: 0000000000000001 R15: 0000000000000001 tomoyo_domain_quota_is_ok+0x1a/0x580 security/tomoyo/util.c:1050 tomoyo_supervisor+0x4b0/0x1340 security/tomoyo/common.c:2224 tomoyo_audit_path_number_log security/tomoyo/file.c:239 [inline] tomoyo_path_number_perm+0x445/0x580 security/tomoyo/file.c:739 security_file_ioctl+0xd3/0x230 security/security.c:2512 __do_sys_ioctl fs/ioctl.c:591 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0xb7/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x115/0x870 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7feb5d19e019 Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 e8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007feb5e05c028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007feb5d425fa0 RCX: 00007feb5d19e019 RDX: 0000200000000200 RSI: 00000000c03064b7 RDI: 0000000000000004 RBP: 00007feb5d23500c R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007feb5d426038 R14: 00007feb5d425fa0 R15: 00007fff2d06ba18