rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=7d14/1/0x4000000000000000 softirq=80542/80543 fqs=7 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P13412/1:b..l P5608/1:b..l rcu: (detected by 1, t=10502 jiffies, g=88529, q=776 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 13415 Comm: syz.2.1862 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:its_return_thunk+0x0/0x10 arch/x86/lib/retpoline.S:417 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 cc 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 00 e9 0b 39 b9 f5 cc RSP: 0018:ffffc90000007e48 EFLAGS: 00000046 RAX: 0000000080010001 RBX: ffff888035c8a300 RCX: ffffffff81f561d2 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff88802c2bca80 RBP: ffff8880b8428540 R08: 0000000000000001 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: ffff8880b8428400 R14: 0000000000000000 R15: 0000000000000000 FS: 00007f95bedc46c0(0000) GS:ffff888123deb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c29ca63 CR3: 000000002c063000 CR4: 00000000003526f0 Call Trace: __remove_hrtimer+0x122/0x440 kernel/time/hrtimer.c:1155 __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:rcu_read_lock include/linux/rcupdate.h:841 [inline] RIP: 0010:timerfd_clock_was_set+0x1e0/0x310 fs/timerfd.c:105 Code: 00 00 00 e8 82 12 60 ff 48 c7 c7 00 61 be 8e 48 8d 35 00 00 00 00 e8 5f a8 3b ff 5b 5d 41 5c 41 5d 41 5e 41 5f e9 c0 09 45 ff 5b 12 60 ff e8 c6 14 44 ff 31 ff 89 c3 89 c6 e8 5b 0c 60 ff 84 RSP: 0018:ffffc9000480fc68 EFLAGS: 00000202 RAX: ffffffff82a9bc36 RBX: 0000000000000001 RCX: ffffffff82a9bc57 RDX: 0000000000000001 RSI: 0000000000000000 RDI: ffff88802c2bca80 RBP: ffff8880b8528400 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000000 R12: fffffbfff22445f2 R13: 1bc16c9fafa874bf R14: 0000000000000000 R15: 0000000000000000 clock_was_set+0x652/0x850 kernel/time/hrtimer.c:1004 do_settimeofday64+0x330/0x4d0 kernel/time/timekeeping.c:1684 do_sys_settimeofday64+0x1dc/0x260 kernel/time/time.c:195 __do_sys_clock_settime kernel/time/posix-timers.c:1139 [inline] __se_sys_clock_settime kernel/time/posix-timers.c:1123 [inline] __x64_sys_clock_settime+0x1c1/0x2a0 kernel/time/posix-timers.c:1123 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: 0033:0x7f95bdf9de59 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:00007f95bedc4028 EFLAGS: 00000246 ORIG_RAX: 00000000000000e3 RAX: ffffffffffffffda RBX: 00007f95be225fa0 RCX: 00007f95bdf9de59 RDX: 0000000000000000 RSI: 0000200000000040 RDI: 0000000000000000 RBP: 00007f95be033e6f R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f95be226038 R14: 00007f95be225fa0 R15: 00007ffca6e9e9f8 task:syz-executor state:R running task stack:22792 pid:5608 tgid:5608 ppid:5603 task_flags:0x400140 flags:0x00080002 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x125c/0x6730 kernel/sched/core.c:7234 preempt_schedule_notrace+0x5f/0xd0 kernel/sched/core.c:7506 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x8e/0xc0 kernel/rcu/tree.c:753 trace_lock_acquire include/trace/events/lock.h:23 [inline] lock_acquire+0x301/0x370 kernel/locking/lockdep.c:5831 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 kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2705 [inline] slab_free mm/slub.c:6405 [inline] kfree+0x22b/0x6c0 mm/slub.c:6720 tomoyo_realpath_from_path+0x19c/0x690 security/tomoyo/realpath.c:286 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x276/0x460 security/tomoyo/file.c:827 tomoyo_path_unlink+0x91/0xe0 security/tomoyo/tomoyo.c:162 security_path_unlink+0x145/0x2b0 security/security.c:1483 filename_unlinkat+0x316/0x730 fs/namei.c:5582 __do_sys_unlink fs/namei.c:5620 [inline] __se_sys_unlink fs/namei.c:5617 [inline] __x64_sys_unlink+0x46/0x70 fs/namei.c:5617 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: 0033:0x7f153019cf47 RSP: 002b:00007ffe780b9948 EFLAGS: 00000206 ORIG_RAX: 0000000000000057 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f153019cf47 RDX: 00007ffe780b9970 RSI: 00007ffe780b9a00 RDI: 00007ffe780b9a00 RBP: 00007ffe780b9a00 R08: 00007ffe780baa00 R09: 00000000ffffffff R10: 0000000000000100 R11: 0000000000000206 R12: 00007ffe780baa90 R13: 00007f15302332ca R14: 00000000000d13ee R15: 00007ffe780baad0 task:syz.6.1861 state:R running task stack:25816 pid:13412 tgid:13410 ppid:11049 task_flags:0x400140 flags:0x00080000 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:__update_page_owner_handle+0x160/0x530 mm/page_owner.c:258 Code: ea 03 4a 8d 04 22 48 89 44 24 30 e8 ea f6 84 ff 48 8b 1d 63 c5 5c 0c 4c 01 fb 48 8d 7b 08 48 89 f8 48 c1 e8 03 42 0f b6 04 20 <84> c0 74 08 3c 03 0f 8e 8f 03 00 00 8b 44 24 0c 89 43 08 48 89 d8 RSP: 0018:ffffc90005266de0 EFLAGS: 00000a02 RAX: 0000000000000000 RBX: ffff88801e524678 RCX: ffffc90012ef3000 RDX: 0000000000080000 RSI: ffffffff8284d956 RDI: ffff88801e524680 RBP: 000000000004ba7b R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: 0000000000000001 R15: ffff88801e524670 __set_page_owner+0x11f/0x540 mm/page_owner.c:342 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859 prep_new_page mm/page_alloc.c:1867 [inline] get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304 alloc_pages_mpol+0x1fb/0x540 mm/mempolicy.c:2490 folio_alloc_mpol_noprof+0x36/0x260 mm/mempolicy.c:2509 shmem_alloc_folio+0x135/0x160 mm/shmem.c:1907 shmem_alloc_and_add_folio+0x371/0xd40 mm/shmem.c:1949 shmem_get_folio_gfp+0x6ad/0x1910 mm/shmem.c:2502 shmem_fault+0x1f9/0xa20 mm/shmem.c:2703 __do_fault+0x10b/0x440 mm/memory.c:5425 do_read_fault mm/memory.c:5860 [inline] do_fault+0xa99/0x1750 mm/memory.c:5994 do_pte_missing mm/memory.c:4566 [inline] handle_pte_fault mm/memory.c:6379 [inline] __handle_mm_fault+0x187d/0x2a00 mm/memory.c:6517 handle_mm_fault+0x37b/0xa30 mm/memory.c:6686 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x1178/0x32a0 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x107/0x3a0 mm/gup.c:1963 mm_populate include/linux/mm.h:4171 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0xe4/0x610 mm/mmap.c:606 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 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: 0033:0x7fb1bc59de59 RSP: 002b:00007fb1bd4f0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fb1bc826090 RCX: 00007fb1bc59de59 RDX: 0000000000000003 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007fb1bc633e6f R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007fb1bc826128 R14: 00007fb1bc826090 R15: 00007ffe02a3ced8 rcu: rcu_preempt kthread starved for 10488 jiffies! g88529 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:28984 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: CPU: 1 UID: 0 PID: 0 Comm: swapper/1 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/10/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:64 Code: a6 8d 02 c3 cc cc cc cc 0f 1f 00 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 79 12 00 fb f4 bc 48 03 00 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 RSP: 0018:ffffc90000197e00 EFLAGS: 00000242 RAX: 00000000044bcefb RBX: ffff88801ea82540 RCX: ffffffff8bb922d5 RDX: 0000000000000000 RSI: ffffffff8e1a3122 RDI: ffffffff8c400c80 RBP: ffffed1003d504a8 R08: 0000000000000001 R09: ffffed10170a678d R10: ffff8880b8533c6b R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff92000032fc4 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff888123eeb000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f94edd76b44 CR3: 000000000e992000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:62 [inline] default_idle+0x9/0x10 arch/x86/kernel/process.c:768 default_idle_call+0x6c/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:199 [inline] do_idle+0x3a7/0x5b0 kernel/sched/idle.c:355 cpu_startup_entry+0x4f/0x60 kernel/sched/idle.c:454 start_secondary+0x21d/0x2d0 arch/x86/kernel/smpboot.c:312 common_startup_64+0x13e/0x158