rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4337/1:b..l (detected by 0, t=10502 jiffies, g=9761, q=155 ncpus=2) task:udevd state:R running task stack:25848 pid:4337 ppid:3623 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 ff 8b 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90004587460 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920008b0e98 RCX: 1ffff920008b0e38 RDX: dffffc0000000000 RSI: ffffffff8b0c14c0 RDI: ffffffff8b5e67c0 RBP: ffffc900045875b8 R08: dffffc0000000000 R09: fffffbfff224a04d R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920008b0e94 R13: dffffc0000000000 R14: ffffc900045874c0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] get_obj_cgroup_from_current+0xf1/0x280 mm/memcontrol.c:3016 memcg_slab_pre_alloc_hook mm/slab.h:485 [inline] slab_pre_alloc_hook+0x90/0x300 mm/slab.h:715 slab_alloc_node mm/slub.c:3318 [inline] __kmem_cache_alloc_node+0x47/0x260 mm/slub.c:3437 __do_kmalloc_node mm/slab_common.c:935 [inline] __kmalloc+0xa1/0x230 mm/slab_common.c:949 kmalloc include/linux/slab.h:568 [inline] __d_alloc+0xb8/0x710 fs/dcache.c:1791 d_alloc fs/dcache.c:1854 [inline] d_alloc_parallel+0xdd/0x1590 fs/dcache.c:2645 lookup_open fs/namei.c:3407 [inline] open_last_lookups fs/namei.c:3550 [inline] path_openat+0x90a/0x2e60 fs/namei.c:3780 do_filp_open+0x230/0x480 fs/namei.c:3810 do_sys_openat2+0x13b/0x4f0 fs/open.c:1318 do_sys_open fs/open.c:1334 [inline] __do_sys_openat fs/open.c:1350 [inline] __se_sys_openat fs/open.c:1345 [inline] __x64_sys_openat+0x243/0x290 fs/open.c:1345 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4d3911a477 RSP: 002b:00007ffc5855cf48 EFLAGS: 00000287 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007ffc5855d388 RCX: 00007f4d3911a477 RDX: 0000000000090800 RSI: 00007ffc5855d388 RDI: 00000000ffffff9c RBP: 0000000000000000 R08: 0000000000090800 R09: 00007ffc5855d388 R10: 0000000000000000 R11: 0000000000000287 R12: 00007ffc5855cf88 R13: 000055ef62f8d860 R14: 000055ef62f77060 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10536 jiffies! g9761 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:26136 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 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: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 57 Comm: kworker/u4:4 Not tainted 6.1.127-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 12/27/2024 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:424 [inline] RIP: 0010:smp_call_function_many_cond+0x1fae/0x3460 kernel/smp.c:998 Code: 2f 44 89 ee 83 e6 01 31 ff e8 0e 44 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 0a e8 99 40 0b 00 e9 1b ff ff ff f3 90 <42> 0f b6 04 2b 84 c0 75 14 41 f7 07 01 00 00 00 0f 84 fe fe ff ff RSP: 0018:ffffc900015875a0 EFLAGS: 00000293 RAX: ffffffff817f5c29 RBX: 1ffff110171c8595 RCX: ffff88801f2f0000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90001587980 R08: ffffffff817f5bf2 R09: fffffbfff224a04d R10: 0000000000000000 R11: dffffc0000000001 R12: 0000000800000000 R13: dffffc0000000000 R14: 0000000000000000 R15: ffff8880b8e42ca8 FS: 0000000000000000(0000) GS:ffff8880b8f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f4fb4a23b10 CR3: 000000000d08e000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: on_each_cpu_cond_mask+0x3b/0x80 kernel/smp.c:1166 on_each_cpu include/linux/smp.h:71 [inline] text_poke_sync arch/x86/kernel/alternative.c:1334 [inline] text_poke_bp_batch+0x2bb/0x940 arch/x86/kernel/alternative.c:1534 text_poke_flush arch/x86/kernel/alternative.c:1725 [inline] text_poke_finish+0x16/0x30 arch/x86/kernel/alternative.c:1732 arch_jump_label_transform_apply+0x13/0x20 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x12e/0x250 kernel/jump_label.c:207 static_key_enable+0x16/0x20 kernel/jump_label.c:220 toggle_allocation_gate+0xbf/0x480 mm/kfence/core.c:804 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295