rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4273/1:b..l (detected by 0, t=10502 jiffies, g=9477, q=267 ncpus=2) task:syz-executor state:R running task stack:21824 pid:4273 ppid:4262 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6873 irqentry_exit+0x63/0x70 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_release+0x593/0x910 kernel/locking/lockdep.c:5686 Code: 00 00 00 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 75 75 f7 44 24 50 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 2f 00 00 00 00 66 43 c7 44 2f 09 00 00 43 c6 44 2f 0b 00 RSP: 0018:ffffc90003df7540 EFLAGS: 00000206 RAX: 0000000000000001 RBX: c47299dddd4ceeee RCX: 7001d57ad0e6dc00 RDX: 0000000000000005 RSI: ffffffff8a8c15a0 RDI: ffffffff8adef6a0 RBP: ffffc90003df7650 R08: dffffc0000000000 R09: fffffbfff1c3ea96 R10: fffffbfff1c3ea96 R11: 1ffffffff1c3ea95 R12: ffff888024640ba8 R13: dffffc0000000000 R14: ffff888024640ad0 R15: 1ffff920007beeb4 rcu_lock_release include/linux/rcupdate.h:355 [inline] rcu_read_unlock include/linux/rcupdate.h:824 [inline] percpu_ref_tryget_many include/linux/percpu-refcount.h:250 [inline] percpu_ref_tryget+0xfd/0x180 include/linux/percpu-refcount.h:266 obj_cgroup_tryget include/linux/memcontrol.h:779 [inline] __get_obj_cgroup_from_memcg+0x70/0xe0 mm/memcontrol.c:3004 get_obj_cgroup_from_current+0x16b/0x280 mm/memcontrol.c:3024 memcg_slab_pre_alloc_hook mm/slab.h:485 [inline] slab_pre_alloc_hook+0x91/0x310 mm/slab.h:715 slab_alloc_node mm/slub.c:3318 [inline] slab_alloc mm/slub.c:3406 [inline] __kmem_cache_alloc_lru mm/slub.c:3413 [inline] kmem_cache_alloc+0x56/0x2f0 mm/slub.c:3422 anon_vma_chain_alloc mm/rmap.c:141 [inline] anon_vma_clone+0xb4/0x4e0 mm/rmap.c:287 anon_vma_fork+0x75/0x4f0 mm/rmap.c:350 dup_mmap kernel/fork.c:663 [inline] dup_mm kernel/fork.c:1541 [inline] copy_mm+0xb44/0x15c0 kernel/fork.c:1590 copy_process+0x1953/0x4020 kernel/fork.c:2351 kernel_clone+0x225/0x8b0 kernel/fork.c:2757 __do_sys_clone kernel/fork.c:2898 [inline] __se_sys_clone kernel/fork.c:2882 [inline] __x64_sys_clone+0x17c/0x1d0 kernel/fork.c:2882 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fd84b585453 RSP: 002b:00007ffd1fbabfa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fd84b585453 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055558695f7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 000000000001561a R15: 00007ffd1fbac140 rcu: rcu_preempt kthread starved for 9479 jiffies! g9477 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:27200 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 schedule+0xb9/0x180 kernel/sched/core.c:6637 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2f2/0x1310 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x95/0x380 kernel/rcu/tree.c:1905 kthread+0x29d/0x330 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.148-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:742 Code: 48 89 df e8 b7 91 b0 f7 e9 4c ff ff ff e8 2d 08 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d b7 55 66 00 fb f4 0f 1f 40 00 41 57 41 56 53 49 be 00 00 00 00 00 fc ff df 65 48 RSP: 0018:ffffffff8c807d88 EFLAGS: 000002c6 RAX: 53b16e78242c7200 RBX: ffffffff8a204e37 RCX: 53b16e78242c7200 RDX: 0000000000000001 RSI: ffffffff8a8c0420 RDI: ffffffff8adef6a0 RBP: ffffffff8c807ec0 R08: dffffc0000000000 R09: ffffed10171c6af6 R10: ffffed10171c6af6 R11: 1ffff110171c6af5 R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8c8bc680 R15: 1ffffffff1c3ead6 FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f37f42e16c8 CR3: 0000000079b90000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: default_idle_call+0x84/0xc0 kernel/sched/idle.c:109 cpuidle_idle_call kernel/sched/idle.c:191 [inline] do_idle+0x1fc/0x570 kernel/sched/idle.c:303 cpu_startup_entry+0x3f/0x60 kernel/sched/idle.c:401 rest_init+0x2dc/0x300 init/main.c:733 arch_call_rest_init+0xa/0xa init/main.c:893 start_kernel+0x490/0x539 init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb