rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4261/1:b..l (detected by 1, t=10503 jiffies, g=9061, q=537 ncpus=2) task:udevd state:R running task stack:23632 pid:4261 ppid:3638 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 preempt_schedule_irq+0xbb/0x160 kernel/sched/core.c:6874 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_is_held_type+0x13a/0x190 kernel/locking/lockdep.c:5710 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:ffffc90003e978b8 EFLAGS: 00000206 RAX: 88e8ef258da71100 RBX: ffff88802e705940 RCX: 88e8ef258da71100 RDX: 0000000000000000 RSI: ffffffff8a8c23a0 RDI: ffffffff8adf0c20 RBP: 0000000000000001 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffffbfff2e0cf7c R12: 0000000000000000 R13: 0000000000000246 R14: ffff88801da7f958 R15: ffff88802e706420 lock_is_held include/linux/lockdep.h:283 [inline] mt_locked lib/maple_tree.c:-1 [inline] mt_slot lib/maple_tree.c:816 [inline] mas_slot lib/maple_tree.c:849 [inline] mas_validate_parent_slot lib/maple_tree.c:7053 [inline] mt_validate+0xf8e/0x4cb0 lib/maple_tree.c:7242 validate_mm_mt+0xe2/0x440 mm/mmap.c:295 validate_mm+0xe1/0x2e0 mm/mmap.c:332 do_mmap+0xc7/0xfd0 mm/mmap.c:1270 vm_mmap_pgoff+0x1c1/0x2d0 mm/util.c:520 do_syscall_x64 arch/x86/entry/common.c:46 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f4bf331d822 RSP: 002b:00007fff7d9ce1f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f4bf331d822 RDX: 0000000000000003 RSI: 0000000000000200 RDI: 0000000000000000 RBP: 0000000000000022 R08: 00000000ffffffff R09: 0000000000000000 R10: 0000000000000022 R11: 0000000000000246 R12: 00000000000001f6 R13: 000000000000fe00 R14: 0000560f3d98f0b0 R15: 0000000000007e00 rcu: rcu_preempt kthread starved for 10518 jiffies! g9061 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:26864 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x11d1/0x40e0 kernel/sched/core.c:6562 schedule+0xb9/0x180 kernel/sched/core.c:6638 schedule_timeout+0x184/0x2d0 kernel/time/timer.c:2168 rcu_gp_fqs_loop+0x303/0x1340 kernel/rcu/tree.c:1706 rcu_gp_kthread+0x99/0x3b0 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 4491 Comm: syz.3.27 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:arch_static_branch arch/x86/include/asm/jump_label.h:27 [inline] RIP: 0010:static_key_false include/linux/jump_label.h:207 [inline] RIP: 0010:native_write_msr arch/x86/include/asm/msr.h:147 [inline] RIP: 0010:wrmsr arch/x86/include/asm/msr.h:254 [inline] RIP: 0010:native_apic_msr_write+0x35/0x50 arch/x86/include/asm/apic.h:206 Code: 74 2a 83 ff 30 74 25 eb 10 81 ff d0 00 00 00 74 1b 81 ff e0 00 00 00 74 13 c1 ef 04 81 c7 00 08 00 00 89 f9 89 f0 31 d2 0f 30 <66> 90 c3 89 f6 31 d2 e9 ef 2f 01 03 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90000007e38 EFLAGS: 00000046 RAX: 0000000000082f35 RBX: 0000000000082f35 RCX: 0000000000000838 RDX: 0000000000000000 RSI: 0000000000082f35 RDI: 0000000000000838 RBP: 0000000000000000 R08: ffffffff8e1fc32f R09: 1ffffffff1c3f865 R10: dffffc0000000000 R11: fffffbfff1c3f866 R12: dffffc0000000000 R13: 00000000100006b5 R14: ffffffff8c64fb40 R15: dffffc0000000000 FS: 00007f367f71e6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000010e0 CR3: 0000000025286000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: apic_write arch/x86/include/asm/apic.h:394 [inline] lapic_next_event+0x5b/0x70 arch/x86/kernel/apic/apic.c:478 clockevents_program_event+0x1bc/0x310 kernel/time/clockevents.c:334 hrtimer_interrupt+0x59d/0x9c0 kernel/time/hrtimer.c:1886 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1107 [inline] __sysvec_apic_timer_interrupt+0x153/0x5a0 arch/x86/kernel/apic/apic.c:1124 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1118 [inline] sysvec_apic_timer_interrupt+0x9b/0xc0 arch/x86/kernel/apic/apic.c:1118 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:160 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:202 Code: 00 00 00 66 90 53 48 89 fb 48 83 c7 18 48 8b 74 24 08 e8 ae 54 2e f7 48 89 df e8 f6 1c 2f f7 e8 71 6d 52 f7 fb bf 01 00 00 00 96 7d 22 f7 65 8b 05 57 01 cc 75 85 c0 74 02 5b c3 e8 a4 15 ca RSP: 0018:ffffc90005397b98 EFLAGS: 00000282 RAX: 10b3de57fc9d2e00 RBX: ffff88807b6a8940 RCX: 10b3de57fc9d2e00 RDX: dffffc0000000000 RSI: ffffffff8a8c1220 RDI: 0000000000000001 RBP: ffff88807b6a8dd8 R08: ffff88807b6a8943 R09: 1ffff1100f6d5128 R10: dffffc0000000000 R11: ffffed100f6d5129 R12: 1ffff1100f6d51bb R13: 0000000000000021 R14: dffffc0000000000 R15: 0000000000000000 spin_unlock_irq include/linux/spinlock.h:401 [inline] get_signal+0x1163/0x1350 kernel/signal.c:2874 arch_do_signal_or_restart+0xc4/0x1350 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x70/0x110 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:303 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:82 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f367e79aeb7 Code: 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 <0f> 05 48 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 RSP: 002b:00007f367f71e0e8 EFLAGS: 00000246 RAX: 00000000000000ca RBX: 00007f367ea15fa8 RCX: 00007f367e79aeb9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f367ea15fa8 RBP: 00007f367ea15fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f367ea16038 R14: 00007fff9d4ee3f0 R15: 00007fff9d4ee4d8