rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5791/1:b..l rcu: (detected by 0, t=10503 jiffies, g=9037, q=33 ncpus=2) task:udevd state:R running task stack:27592 pid:5791 ppid:5160 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 preempt_schedule_irq+0xb5/0x140 kernel/sched/core.c:7009 irqentry_exit+0x67/0x70 kernel/entry/common.c:438 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:687 RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0000:ffffc900044bfb38 EFLAGS: 00000206 RAX: 7b4d73177b356000 RBX: ffff88806a1abc00 RCX: 7b4d73177b356000 RDX: 0000000000000000 RSI: ffffffff8aaace60 RDI: ffffffff8afc6b00 RBP: 0000000000000000 R08: dffffc0000000000 R09: 1ffffffff21b50a0 R10: dffffc0000000000 R11: fffffbfff21b50a1 R12: 0000000000000002 R13: 0000000000000246 R14: ffffffff8cd598b8 R15: ffff88806a1ac730 lock_is_held include/linux/lockdep.h:288 [inline] task_css include/linux/cgroup.h:436 [inline] mem_cgroup_from_task+0x77/0x110 mm/memcontrol.c:1009 count_memcg_event_mm+0x19a/0x3b0 include/linux/memcontrol.h:1101 mm_account_fault mm/memory.c:5200 [inline] handle_mm_fault+0x2857/0x4920 mm/memory.c:5347 do_user_addr_fault+0xad0/0x12e0 arch/x86/mm/fault.c:1324 handle_page_fault arch/x86/mm/fault.c:1465 [inline] exc_page_fault+0x67/0x110 arch/x86/mm/fault.c:1521 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:608 RIP: 0033:0x7fbce2ddedd9 RSP: 002b:00007ffe136da0e0 EFLAGS: 00010246 RAX: 00007fbce2f17b20 RBX: 0000000000001010 RCX: 0000000000000040 RDX: 0000560274865a00 RSI: 00007fbce2f18140 RDI: 00005602748649f0 RBP: 00007fbce2f17ac0 R08: 00000000000000ff R09: 0000000000000000 R10: 00007fbce2f17b50 R11: 000000000000000c R12: 0000000000001000 R13: 00005602748649f0 R14: 0000000000001050 R15: 00007fbce2f17b20 rcu: rcu_preempt kthread starved for 10533 jiffies! g9037 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:27752 pid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5380 [inline] __schedule+0x14d2/0x44d0 kernel/sched/core.c:6699 schedule+0xbd/0x170 kernel/sched/core.c:6773 schedule_timeout+0x160/0x280 kernel/time/timer.c:2167 rcu_gp_fqs_loop+0x302/0x1560 kernel/rcu/tree.c:1667 rcu_gp_kthread+0x99/0x380 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: CPU: 0 PID: 5798 Comm: syz-executor326 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:lock_is_held_type+0x13e/0x190 kernel/locking/lockdep.c:5830 Code: 75 40 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 46 41 f7 c5 00 02 00 00 74 01 fb 65 48 8b 04 25 28 00 00 00 <48> 3b 44 24 08 75 3c 89 e8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f RSP: 0018:ffffc9000456fb38 EFLAGS: 00000206 RAX: 966e4a683c209e00 RBX: ffff88802ebf5a00 RCX: 966e4a683c209e00 RDX: 0000000000000000 RSI: ffffffff8aaace60 RDI: ffffffff8afc6b00 RBP: 0000000000000000 R08: ffffc9000456fe5f R09: 0000000000000000 R10: ffffc9000456fd60 R11: fffff520008adfcc R12: dffffc0000000000 R13: 0000000000000246 R14: ffffffff8cd2ff40 R15: 00000000ffffffff FS: 00007f8f228326c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f8f22831f80 CR3: 000000002e2ac000 CR4: 00000000003506f0 Call Trace: lock_is_held include/linux/lockdep.h:288 [inline] __might_resched+0xa7/0x610 kernel/sched/core.c:10170 __might_fault+0x71/0x120 mm/memory.c:5944 _copy_from_user+0x2a/0xe0 lib/usercopy.c:14 copy_from_user include/linux/uaccess.h:183 [inline] restore_sigcontext arch/x86/kernel/signal_64.c:59 [inline] __ia32_sys_rt_sigreturn+0x27a/0x7b0 arch/x86/kernel/signal_64.c:266 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x55/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f8f22844aa9 Code: 64 c7 00 16 00 00 00 b8 ff ff ff ff c3 0f 1f 40 00 90 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 c7 c0 0f 00 00 00 0f 05 <0f> 1f 80 00 00 00 00 48 81 ec 48 01 00 00 49 89 d0 64 48 8b 04 25 RSP: 002b:00007f8f22831bc0 EFLAGS: 00000202 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007f8f228fc308 RCX: 00007f8f22844aa9 RDX: 00007f8f22831bc0 RSI: 00007f8f22831cf0 RDI: 0000000000000021 RBP: 00007f8f228fc300 R08: 0000000000000000 R09: 00007f8f228326c0 R10: 00007f8f228326c0 R11: 0000000000000202 R12: 00007f8f228fc30c R13: 0000000000000000 R14: 00007ffc9d6d9f10 R15: 00007ffc9d6d9ff8