rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: (detected by 1, t=10502 jiffies, g=9797, q=3821 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10480 (4294958381-4294947901), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10481 jiffies! g9797 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:27848 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x15ae/0x4660 kernel/sched/core.c:6701 schedule+0xbd/0x170 kernel/sched/core.c:6775 schedule_timeout+0x188/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x30d/0x1590 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:1866 kthread+0x2fa/0x390 kernel/kthread.c:388 ret_from_fork+0x48/0x80 arch/x86/kernel/process.c:152 ret_from_fork_asm+0x11/0x20 arch/x86/entry/entry_64.S:293 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 6038 Comm: syz.0.64 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/16/2026 RIP: 0010:find_held_lock kernel/locking/lockdep.c:-1 [inline] RIP: 0010:__lock_release kernel/locking/lockdep.c:5465 [inline] RIP: 0010:lock_release+0x207/0x8c0 kernel/locking/lockdep.c:5810 Code: 89 44 24 30 83 f8 32 0f 83 d3 04 00 00 4b 8d 04 b6 4c 8d 24 c3 48 89 c3 4c 89 e7 48 8b 74 24 18 e8 3e 91 29 09 44 89 7c 24 3c <44> 89 fa 85 c0 0f 84 d7 01 00 00 4d 85 e4 0f 84 01 03 00 00 4d 8d RSP: 0018:ffffc90000007120 EFLAGS: 00000046 RAX: 0000000000000001 RBX: 0000000000000014 RCX: 9d48c6afd793ff00 RDX: 1ffff11004e91c9c RSI: ffffffff8d14bc88 RDI: ffff88802748e588 RBP: ffffc90000007230 R08: ffffffff8e8c626f R09: 1ffffffff1d18c4d R10: dffffc0000000000 R11: fffffbfff1d18c4e R12: ffff88802748e588 R13: dffffc0000000000 R14: 0000000000000004 R15: 0000000000000004 FS: 00007f9a033d56c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000100000000 CR3: 000000002da50000 CR4: 00000000003506f0 DR0: 0000000000000008 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: seqcount_lockdep_reader_access+0xe4/0x1d0 include/linux/seqlock.h:103 timekeeping_get_delta kernel/time/timekeeping.c:254 [inline] timekeeping_get_ns kernel/time/timekeeping.c:388 [inline] ktime_get+0x7f/0x280 kernel/time/timekeeping.c:848 hrtimer_forward_now include/linux/hrtimer.h:509 [inline] perf_swevent_hrtimer+0x4ae/0x610 kernel/events/core.c:11235 __run_hrtimer kernel/time/hrtimer.c:1754 [inline] __hrtimer_run_queues+0x4e8/0xc10 kernel/time/hrtimer.c:1818 hrtimer_interrupt+0x39d/0x980 kernel/time/hrtimer.c:1880 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1077 [inline] __sysvec_apic_timer_interrupt+0xfb/0x3b0 arch/x86/kernel/apic/apic.c:1094 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0x51/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] RIP: 0010:_raw_spin_unlock_irqrestore+0xc0/0x120 kernel/locking/spinlock.c:194 Code: c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 41 c6 04 07 f8 75 4b f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 ab 96 c0 f6 65 8b 05 1c 54 67 75 85 c0 74 3c 48 c7 04 24 0e 36 RSP: 0018:ffffc90000007900 EFLAGS: 00000206 RAX: dffffc0000000004 RBX: 0000000000000a02 RCX: 9d48c6afd793ff00 RDX: dffffc0000000000 RSI: ffffffff8acacce0 RDI: 0000000000000001 RBP: ffffc90000007980 R08: ffffffff911f0617 R09: 1ffffffff223e0c2 R10: dffffc0000000000 R11: fffffbfff223e0c3 R12: dffffc0000000000 R13: ffff88805c1c9f50 R14: ffffffff974b5dd8 R15: 1ffff92000000f20 debug_object_assert_init+0x1f1/0x300 lib/debugobjects.c:946 debug_timer_assert_init kernel/time/timer.c:792 [inline] debug_assert_init kernel/time/timer.c:837 [inline] __timer_delete+0x3f/0x290 kernel/time/timer.c:1321 del_timer include/linux/timer.h:213 [inline] inet_frag_destroy+0x7b/0x290 net/ipv4/inet_fragment.c:354 inet_frag_putn include/net/inet_frag.h:139 [inline] ip_expire+0x55b/0x850 net/ipv4/ip_fragment.c:192 call_timer_fn+0x189/0x540 kernel/time/timer.c:1701 expire_timers kernel/time/timer.c:1752 [inline] __run_timers+0x570/0x810 kernel/time/timer.c:2023 run_timer_softirq+0x67/0xf0 kernel/time/timer.c:2036 handle_softirqs+0x27d/0x820 kernel/softirq.c:578 __do_softirq kernel/softirq.c:612 [inline] invoke_softirq kernel/softirq.c:452 [inline] __irq_exit_rcu+0xd3/0x190 kernel/softirq.c:661 irq_exit_rcu+0x9/0x20 kernel/softirq.c:673 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1088 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1088 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:deref_stack_reg+0x0/0x230 arch/x86/kernel/unwind_orc.c:402 Code: e2 07 80 c2 03 38 c2 0f 8c d5 fe ff ff 48 89 4c 24 18 e8 33 58 a4 00 48 8b 4c 24 18 e9 c1 fe ff ff 66 0f 1f 84 00 00 00 00 00 <55> 41 57 41 56 41 55 41 54 53 48 83 ec 18 48 89 54 24 10 48 89 34 RSP: 0018:ffffc9000b6af530 EFLAGS: 00000283 RAX: fffffffffffffff0 RBX: ffffffff8f1bb40d RCX: 0000000000000003 RDX: ffffc9000b6af648 RSI: ffffc9000b6afa70 RDI: ffffc9000b6af608 RBP: ffffc9000b6af658 R08: ffff88802748da00 R09: 0000000000000003 R10: 0000000000000004 R11: 0000000000000002 R12: ffffc9000b6afa58 R13: ffffc9000b6af608 R14: ffffffff8f1bb40c R15: dffffc0000000000 unwind_next_frame+0x1781/0x2990 arch/x86/kernel/unwind_orc.c:648 arch_stack_walk+0x144/0x190 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xaa/0x100 kernel/stacktrace.c:122 save_stack+0x125/0x230 mm/page_owner.c:128 __reset_page_owner+0x4e/0x190 mm/page_owner.c:149 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1182 [inline] free_unref_page_prepare+0x7d7/0x8f0 mm/page_alloc.c:2366 free_unref_page+0x32/0x2e0 mm/page_alloc.c:2459 __slab_free+0x35a/0x400 mm/slub.c:3736 qlink_free mm/kasan/quarantine.c:166 [inline] qlist_free_all+0x75/0xd0 mm/kasan/quarantine.c:185 kasan_quarantine_reduce+0x143/0x160 mm/kasan/quarantine.c:292 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:306 kasan_slab_alloc include/linux/kasan.h:188 [inline] slab_post_alloc_hook+0x6a/0x4d0 mm/slab.h:770 slab_alloc_node mm/slub.c:3495 [inline] __kmem_cache_alloc_node+0x194/0x250 mm/slub.c:3534 __do_kmalloc_node mm/slab_common.c:1006 [inline] __kmalloc+0xa7/0x240 mm/slab_common.c:1020 kmalloc include/linux/slab.h:604 [inline] tomoyo_realpath_from_path+0xe6/0x5c0 security/tomoyo/realpath.c:251 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_number_perm+0x248/0x5e0 security/tomoyo/file.c:723 security_file_ioctl+0x70/0xa0 security/security.c:2735 __do_sys_ioctl fs/ioctl.c:865 [inline] __se_sys_ioctl+0x48/0x170 fs/ioctl.c:857 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f9a0519e199 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:00007f9a033d5028 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f9a05426090 RCX: 00007f9a0519e199 RDX: 0000200000000000 RSI: 00000000400454ca RDI: 000000000000000b RBP: 00007f9a052358e0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9a05426128 R14: 00007f9a05426090 R15: 00007fff9c0a4318