rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P9671/1:b..l P10644/1:b..l (detected by 0, t=10502 jiffies, g=56025, q=110 ncpus=2) task:udevd state:R running task stack:23584 pid:10644 ppid:3624 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 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:seqcount_lockdep_reader_access+0x17a/0x1c0 include/linux/seqlock.h:105 Code: ff 4d 85 ed 75 16 e8 65 ac 9c ff eb 15 e8 5e ac 9c ff e8 c9 f9 2a 08 4d 85 ed 74 ea e8 4f ac 9c ff fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 66 43 c7 44 27 09 00 00 43 c6 44 27 0b 00 RSP: 0018:ffffc9000c5bf7a0 EFLAGS: 00000293 RAX: ffffffff81e41751 RBX: 0000000000000000 RCX: ffff888029cc8000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc9000c5bf850 R08: dffffc0000000000 R09: fffffbfff1bfd03e R10: fffffbfff1bfd03e R11: 1ffffffff1bfd03d R12: dffffc0000000000 R13: 0000000000000200 R14: ffffffff81e41d0e R15: 1ffff920018b7ef4 set_root+0x15e/0x3a0 fs/namei.c:945 nd_jump_root+0x2a7/0x410 fs/namei.c:966 path_init+0x3e5/0x1200 fs/namei.c:2389 path_openat+0x187/0x2e70 fs/namei.c:3778 do_filp_open+0x1c1/0x3c0 fs/namei.c:3810 do_sys_openat2+0x142/0x490 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+0x135/0x160 fs/open.c:1345 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: 0033:0x7f32bc3169a4 RSP: 002b:00007ffd1d9c31d0 EFLAGS: 00000246 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f32bc3169a4 RDX: 0000000000080241 RSI: 00007ffd1d9c3718 RDI: 00000000ffffff9c RBP: 00007ffd1d9c3718 R08: 0000000000000004 R09: 0000000000000001 R10: 00000000000001b6 R11: 0000000000000246 R12: 0000000000080241 R13: 000056421184672e R14: 0000000000000001 R15: 000056421da8c910 task:syz-executor state:R running task stack:21792 pid:9671 ppid:9647 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 kernel/sched/core.c:6561 preempt_schedule_notrace+0xca/0x110 kernel/sched/core.c:6823 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 kvm_clock_read arch/x86/kernel/kvmclock.c:80 [inline] kvm_sched_clock_read+0x2a/0x40 arch/x86/kernel/kvmclock.c:91 sched_clock_cpu+0x6e/0x250 kernel/sched/clock.c:369 local_clock include/linux/sched/clock.h:84 [inline] __set_page_owner_handle+0x1a9/0x3c0 mm/page_owner.c:174 __set_page_owner+0x41/0x60 mm/page_owner.c:195 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2532 prep_new_page mm/page_alloc.c:2539 [inline] get_page_from_freelist+0x1a26/0x1ac0 mm/page_alloc.c:4328 __alloc_pages+0x1df/0x4e0 mm/page_alloc.c:5606 __folio_alloc+0xe/0x30 mm/page_alloc.c:5638 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243 alloc_page_vma include/linux/gfp.h:284 [inline] wp_page_copy+0x26c/0x1640 mm/memory.c:3153 handle_pte_fault mm/memory.c:5049 [inline] __handle_mm_fault mm/memory.c:5173 [inline] handle_mm_fault+0x1ca6/0x3e70 mm/memory.c:5294 do_user_addr_fault+0x51f/0xb10 arch/x86/mm/fault.c:1340 handle_page_fault arch/x86/mm/fault.c:1431 [inline] exc_page_fault+0x60/0x100 arch/x86/mm/fault.c:1487 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7f629b34d528 RSP: 002b:00007ffde9b136d0 EFLAGS: 00010246 RAX: 0000000000000000 RBX: 00007f629b583ca0 RCX: 00007f629b3851d3 RDX: 000000000000005e RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007f629b583ca0 R08: 0000000000000000 R09: 0000000000000001 R10: 000055556c46a7d0 R11: 0000000000000246 R12: 0000000000000000 R13: ffffffffffffffa8 R14: 0000000000000006 R15: 00007ffde9b13880 rcu: rcu_preempt kthread starved for 10563 jiffies! g56025 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:27464 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10e9/0x40d0 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 6.1.137-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025 RIP: 0010:default_idle+0xb/0x10 arch/x86/kernel/process.c:736 Code: 48 89 df e8 67 3a b9 f7 e9 4c ff ff ff e8 4d 14 f6 ff 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 66 90 0f 00 2d b7 a2 4d 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:ffffffff8c607d88 EFLAGS: 000002c6 RAX: 1e8f88c179290f00 RBX: ffffffff8a1900d7 RCX: 1e8f88c179290f00 RDX: 0000000000000001 RSI: ffffffff8a6bfe00 RDI: ffffffff8abf0da0 RBP: ffffffff8c607ec0 R08: dffffc0000000000 R09: ffffed10171c6aee R10: ffffed10171c6aee R11: 1ffff110171c6aed R12: 0000000000000000 R13: dffffc0000000000 R14: ffffffff8c6bc680 R15: 1ffffffff1bfd07e FS: 0000000000000000(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000555557bed5c8 CR3: 000000005d72c000 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