rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5996/1:b..l rcu: (detected by 0, t=10502 jiffies, g=9185, q=1067188 ncpus=2) task:syz-executor state:R running task stack:27576 pid:5996 tgid:5996 ppid:5839 task_flags:0x400040 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7090 irqentry_exit+0x6f/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x17db/0x2390 arch/x86/kernel/unwind_orc.c:664 Code: 49 0f bf 04 24 48 01 c6 4c 89 f7 48 89 da e8 4c 0e 00 00 84 c0 0f 84 47 01 00 00 48 bd 00 00 00 00 00 fc ff df 48 8b 44 24 20 <0f> b6 04 28 84 c0 0f 85 f4 08 00 00 b3 01 8b 84 24 84 00 00 00 41 RSP: 0018:ffffc9000449f3f8 EFLAGS: 00000202 RAX: 1ffff92000893e99 RBX: ffffffff90196386 RCX: 0000000000000001 RDX: ffffc9000449f508 RSI: dffffc0000000000 RDI: ffffc9000449f7e0 RBP: dffffc0000000000 R08: ffffc9000449f7e0 R09: 0000000000000000 R10: ffffc9000449f518 R11: fffff52000893ea5 R12: ffffc9000449f7e0 R13: ffffc9000449f518 R14: ffffc9000449f4c8 R15: 1ffffffff2032c71 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf7/0x1f0 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:1262 [inline] __free_frozen_pages+0xb0e/0xcd0 mm/page_alloc.c:2725 discard_slab mm/slub.c:2716 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3185 put_cpu_partial+0x17c/0x250 mm/slub.c:3260 __slab_free+0x2f7/0x400 mm/slub.c:4512 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x22/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4327 [inline] __kmalloc_noprof+0x27a/0x4f0 mm/slub.c:4339 kmalloc_noprof include/linux/slab.h:909 [inline] kzalloc_noprof include/linux/slab.h:1039 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x28b/0x550 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x58d/0x5d0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x213/0x4b0 security/tomoyo/file.c:822 tomoyo_path_symlink+0xa3/0xe0 security/tomoyo/tomoyo.c:212 security_path_symlink+0x177/0x380 security/security.c:1984 do_symlinkat+0x107/0x3f0 fs/namei.c:4747 __do_sys_symlinkat fs/namei.c:4765 [inline] __se_sys_symlinkat fs/namei.c:4762 [inline] __x64_sys_symlinkat+0x95/0xb0 fs/namei.c:4762 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fde2698dee7 RSP: 002b:00007fde26cdfda8 EFLAGS: 00000202 ORIG_RAX: 000000000000010a RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fde2698dee7 RDX: 00007fde26a12308 RSI: 00000000ffffff9c RDI: 00007fde26cdfe40 RBP: 00007fde26cdfdec R08: 0000000000000017 R09: 00007fde26cdfaf7 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000006 R13: 00000000000927c0 R14: 0000000000013d47 R15: 00007fde26cdfe40 rcu: rcu_preempt kthread starved for 9975 jiffies! g9185 f0x2 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x16e2/0x4cd0 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x165/0x360 kernel/sched/core.c:6860 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2046 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2248 kthread+0x70e/0x8a0 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: 0 Comm: swapper/0 Not tainted 6.15.0-rc5-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/29/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:81 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d c3 ea 11 00 f3 0f 1e fa fb f4 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8dc07d80 EFLAGS: 000002c6 RAX: 07df132aa246e300 RBX: ffffffff81974f28 RCX: 07df132aa246e300 RDX: 0000000000000001 RSI: ffffffff8d74aa77 RDI: ffffffff8bc1d1e0 RBP: ffffffff8dc07ec0 R08: ffff8880b8832b5b R09: 1ffff1101710656b R10: dffffc0000000000 R11: ffffed101710656c R12: ffffffff8f7ed970 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1b92a48 FS: 0000000000000000(0000) GS:ffff8881260cb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000020000034a030 CR3: 0000000031b9a000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:748 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:743 start_kernel+0x470/0x4f0 init/main.c:1099 x86_64_start_reservations+0x2a/0x30 arch/x86/kernel/head64.c:513 x86_64_start_kernel+0x66/0x70 arch/x86/kernel/head64.c:494 common_startup_64+0x13e/0x147