rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4391/1:b..l (detected by 0, t=10503 jiffies, g=43845, q=99 ncpus=2) task:udevd state:R running task stack:22080 pid:4391 ppid:3637 flags:0x00004002 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:debug_lockdep_rcu_enabled+0x9/0x30 kernel/rcu/update.c:280 Code: 20 04 8c 8a 48 c7 c6 00 28 8c 8a e8 71 23 35 f7 0f 0b eb d1 00 00 cc cc 00 00 cc cc 00 00 cc cc 00 31 c0 83 3d e7 93 07 04 00 <74> 1d 83 3d 72 c7 07 04 00 74 14 65 48 8b 0d 44 97 ea 75 31 c0 83 RSP: 0018:ffffc900046f74f8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 000000000000000b RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 000000000000000e RDI: 000000000000000b RBP: ffffc900046f76d0 R08: ffff88807b4a5940 R09: 0000000000000003 R10: 0000000000000003 R11: 0000000000000000 R12: ffff8880265b85e8 R13: ffff88807285be80 R14: ffff888028616180 R15: ffff88807285bee0 mt_slot lib/maple_tree.c:814 [inline] mas_slot lib/maple_tree.c:847 [inline] mt_validate_nulls lib/maple_tree.c:7191 [inline] mt_validate+0x4335/0x4c90 lib/maple_tree.c:7247 validate_mm_mt+0xcd/0x420 mm/mmap.c:295 validate_mm+0xcc/0x2b0 mm/mmap.c:332 __vma_adjust+0x17e0/0x1c60 mm/mmap.c:879 vma_adjust include/linux/mm.h:2810 [inline] __split_vma+0x3a7/0x500 mm/mmap.c:-1 do_mas_align_munmap+0x351/0x1220 mm/mmap.c:2480 do_mas_munmap+0x240/0x2b0 mm/mmap.c:2650 __vm_munmap+0x18d/0x290 mm/mmap.c:2936 __do_sys_munmap mm/mmap.c:2961 [inline] __se_sys_munmap mm/mmap.c:2958 [inline] __x64_sys_munmap+0x5c/0x70 mm/mmap.c:2958 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: 0033:0x7ff38f852097 RSP: 002b:00007fff38680a48 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 00005571f7f89c30 RCX: 00007ff38f852097 RDX: 00005571f7f19828 RSI: 0000000000000200 RDI: 00007ff38f15b000 RBP: 000000000000000f R08: 00005571f7f89c00 R09: 0000000000000003 R10: 0000000000000040 R11: 0000000000000246 R12: 00005571f7f1b1f0 R13: 00007ff38f9f439c R14: 0000000000001e00 R15: 0000000000000009 rcu: rcu_preempt kthread starved for 10524 jiffies! g43845 f0x0 RCU_GP_DOING_FQS(6) ->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:26880 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 kernel/sched/core.c:6561 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:6730 preempt_schedule+0xa7/0xb0 kernel/sched/core.c:6754 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xf6/0x100 kernel/locking/spinlock.c:194 force_qs_rnp kernel/rcu/tree.c:-1 [inline] rcu_gp_fqs kernel/rcu/tree.c:-1 [inline] rcu_gp_fqs_loop+0x6a1/0x1310 kernel/rcu/tree.c:1728 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: 8773 Comm: syz.2.925 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 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 1f ea f7 02 66 2e 0f 1f 84 00 00 00 00 00 RSP: 0018:ffffc90004e97cb0 EFLAGS: 00000246 RAX: 00000000000000f6 RBX: ffffffff8c5e4b88 RCX: 000000000000083f RDX: 0000000000000000 RSI: 00000000000000f6 RDI: 000000000000083f RBP: 0000000000000000 R08: dffffc0000000000 R09: fffff520009d2f85 R10: fffff520009d2f85 R11: 1ffff920009d2f84 R12: ffff8880b8e33e01 R13: dffffc0000000000 R14: dffffc0000000000 R15: 0000000000000020 FS: 0000555571113500(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d8d3ed000 CR3: 000000005fa0a000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: arch_irq_work_raise+0x82/0xd0 arch/x86/kernel/irq_work.c:31 irq_work_queue+0x95/0x140 kernel/irq_work.c:114 bpf_send_signal_common+0x2b2/0x420 kernel/trace/bpf_trace.c:879 ____bpf_send_signal kernel/trace/bpf_trace.c:888 [inline] bpf_send_signal+0x15/0x20 kernel/trace/bpf_trace.c:886 bpf_prog_7ba5217f62dcd359+0x38/0x3c bpf_dispatcher_nop_func include/linux/bpf.h:1012 [inline] __bpf_prog_run include/linux/filter.h:603 [inline] bpf_prog_run include/linux/filter.h:610 [inline] __bpf_trace_run kernel/trace/bpf_trace.c:2285 [inline] bpf_trace_run2+0x1cd/0x3b0 kernel/trace/bpf_trace.c:2324 __bpf_trace_sys_enter+0x60/0x70 include/trace/events/syscalls.h:18 trace_sys_enter+0x6b/0x80 include/trace/events/syscalls.h:18 syscall_trace_enter+0xf0/0x150 kernel/entry/common.c:81 do_syscall_64+0x24/0xa0 arch/x86/entry/common.c:77 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7fa4b652b829 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:00007ffe7918c180 EFLAGS: 00000246 ORIG_RAX: 000000000000000f RAX: ffffffffffffffda RBX: 00007fa4b67e6098 RCX: 00007fa4b652b829 RDX: 00007ffe7918c180 RSI: 00007ffe7918c2b0 RDI: 0000000000000011 RBP: 0000000000000001 R08: 0000000000000006 R09: 000000137918ca1f R10: 00007fa4b67e5fa0 R11: 0000000000000246 R12: 00007fa4b67e609c R13: 00007fa4b67e6090 R14: 00000000000010a7 R15: 0000000000000005