rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5820/1:b..l rcu: (detected by 0, t=10502 jiffies, g=17645, q=583 ncpus=2) task:syz-executor state:R running task stack:21728 pid:5820 tgid:5820 ppid:5816 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1522/0x51d0 kernel/sched/core.c:6867 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7194 irqentry_exit+0x597/0x620 kernel/entry/common.c:216 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2d7/0x3a0 kernel/locking/lockdep.c:5893 Code: 95 52 11 00 00 00 00 eb b5 e8 c5 9e f6 09 f7 c3 00 02 00 00 74 b9 65 48 8b 05 b5 4f 52 11 48 3b 44 24 28 75 44 fb 48 83 c4 30 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 85 c0 6f ff cc 48 8d 3d 52 ec 51 RSP: 0018:ffffc90003b3f728 EFLAGS: 00000286 RAX: 39caa23603de4900 RBX: 0000000000000202 RCX: 0000000000000046 RDX: 0000000000000000 RSI: ffffffff8df35112 RDI: ffffffff8c073b00 RBP: ffff88807683e6b0 R08: ffffffff82363f39 R09: ffffffff8e55a360 R10: dffffc0000000000 R11: ffffed100375c139 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e55a360 R15: ffff88807683db80 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] percpu_ref_get_many+0xf9/0x140 include/linux/percpu-refcount.h:209 percpu_ref_get include/linux/percpu-refcount.h:222 [inline] obj_cgroup_get include/linux/memcontrol.h:781 [inline] __memcg_kmem_charge_page+0x30d/0x410 mm/memcontrol.c:2869 __alloc_frozen_pages_noprof+0x1c1/0x380 mm/page_alloc.c:5257 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2486 alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline] alloc_pages_noprof+0xa8/0x190 mm/mempolicy.c:2577 pagetable_alloc_noprof include/linux/mm.h:3194 [inline] __pgd_alloc_noprof include/asm-generic/pgalloc.h:285 [inline] _pgd_alloc arch/x86/mm/pgtable.c:314 [inline] pgd_alloc+0x44/0x730 arch/x86/mm/pgtable.c:328 mm_alloc_pgd kernel/fork.c:576 [inline] mm_init+0x617/0xc50 kernel/fork.c:1114 dup_mm kernel/fork.c:1525 [inline] copy_mm+0x122/0x4b0 kernel/fork.c:1581 copy_process+0x166e/0x3980 kernel/fork.c:2221 kernel_clone+0x248/0x870 kernel/fork.c:2651 __do_sys_clone kernel/fork.c:2792 [inline] __se_sys_clone kernel/fork.c:2776 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2776 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xe2/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f914f9c3a12 RSP: 002b:00007ffd54f30e30 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffd54f30e30 RCX: 00007f914f9c3a12 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffd54f30fbc R08: 0000000000000000 R09: 0000000000000001 R10: 000055555d9127d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 000000000002abf2 R15: 00007ffd54f31010 rcu: rcu_preempt kthread starved for 10528 jiffies! g17645 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:27512 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5260 [inline] __schedule+0x1522/0x51d0 kernel/sched/core.c:6867 __schedule_loop kernel/sched/core.c:6949 [inline] schedule+0x164/0x360 kernel/sched/core.c:6964 schedule_timeout+0x158/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x312/0x1560 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x9d/0x3b0 kernel/rcu/tree.c:2285 kthread+0x726/0x8b0 kernel/kthread.c:463 ret_from_fork+0x51b/0xa40 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026 RIP: 0010:pv_native_safe_halt+0xf/0x20 arch/x86/kernel/paravirt.c:82 Code: 98 60 02 e9 fe 25 79 f5 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 53 49 12 00 fb f4 d7 25 79 f5 cc cc cc cc cc cc cc cc cc cc cc cc 90 90 90 90 90 RSP: 0018:ffffffff8e207dc0 EFLAGS: 00000246 RAX: 0000000000c9aa69 RBX: ffffffff8199570d RCX: 0000000080000001 RDX: 0000000000000001 RSI: ffffffff8dcc9ce4 RDI: ffffffff8c073b00 RBP: ffffffff8e207eb0 R08: ffff8880b86336db R09: 1ffff110170c66db R10: dffffc0000000000 R11: ffffed10170c66dc R12: ffffffff8fef2070 R13: 1ffffffff1c52a78 R14: 0000000000000000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff8881256f3000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000000300 CR3: 00000000786d0000 CR4: 0000000000350ef0 Call Trace: arch_safe_halt arch/x86/kernel/process.c:766 [inline] default_idle+0x9/0x20 arch/x86/kernel/process.c:767 default_idle_call+0x72/0xb0 kernel/sched/idle.c:122 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1bd/0x500 kernel/sched/idle.c:332 cpu_startup_entry+0x43/0x60 kernel/sched/idle.c:430 rest_init+0x2de/0x300 init/main.c:757 start_kernel+0x380/0x3d0 init/main.c:1206 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:310 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:291 common_startup_64+0x13e/0x147 raw-gadget.0 gadget.3: ignoring, device is not running