rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12824/1:b..l (detected by 1, t=10503 jiffies, g=84013, q=411 ncpus=2) task:dhcpcd-run-hook state:R running task stack:24352 pid:12824 ppid:3935 flags:0x00004000 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:lock_is_held_type+0x7/0x190 kernel/locking/lockdep.c:5690 Code: c7 c7 a0 03 8c 8a 48 c7 c6 e0 03 8c 8a e8 01 66 35 f7 0f 0b eb bf e8 98 fd ff ff 0f 1f 84 00 00 00 00 00 55 41 57 41 56 41 55 <41> 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 48 89 44 24 08 bd RSP: 0018:ffffc90003337598 EFLAGS: 00000246 RAX: 1ffff1100e844c30 RBX: 0000000000000000 RCX: dffffc0000000000 RDX: 0000000000000000 RSI: 00000000ffffffff RDI: ffff8880742262d8 RBP: ffffc90003337790 R08: ffff888030039dc0 R09: 0000000000000003 R10: 0000000000000003 R11: 0000000000000000 R12: ffff8880742262d8 R13: 000000000000000a R14: 0000000000000300 R15: 000000000000000f lock_is_held include/linux/lockdep.h:283 [inline] mt_locked lib/maple_tree.c:-1 [inline] mt_slot lib/maple_tree.c:814 [inline] mas_slot lib/maple_tree.c:847 [inline] mas_validate_limits lib/maple_tree.c:7154 [inline] mt_validate+0x2256/0x4c90 lib/maple_tree.c:7242 validate_mm_mt+0xcd/0x420 mm/mmap.c:295 validate_mm+0xcc/0x2b0 mm/mmap.c:332 vma_expand+0x828/0x880 mm/mmap.c:604 __mmap_region mm/mmap.c:2740 [inline] mmap_region+0xc24/0x1c70 mm/mmap.c:2916 do_mmap+0x958/0xfd0 mm/mmap.c:1436 vm_mmap_pgoff+0x1b2/0x2b0 mm/util.c:520 ksys_mmap_pgoff+0x516/0x6f0 mm/mmap.c:1482 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: 0033:0x7f71f9f51242 RSP: 002b:00007fff666158e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f71f9e01000 RCX: 00007f71f9f51242 RDX: 0000000000000001 RSI: 0000000000057000 RDI: 00007f71f9e01000 RBP: 0000000000000812 R08: 0000000000000003 R09: 0000000000176000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007fff66615970 R13: 00007f71f9f2d5f0 R14: 00007fff66616120 R15: 00000fffeccc2b20 rcu: rcu_preempt kthread starved for 10479 jiffies! g84013 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:27432 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x10ec/0x40b0 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 12826 Comm: syz.2.1700 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:lockdep_softirqs_off+0x11/0x420 kernel/locking/lockdep.c:4470 Code: 6e 00 48 ba 00 00 00 00 00 fc ff df e9 0f fe ff ff 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 <48> 81 ec 80 00 00 00 65 48 8b 04 25 28 00 00 00 48 89 44 24 60 49 RSP: 0018:ffffc90003307a40 EFLAGS: 00000082 RAX: 0000000080000000 RBX: 0000000000000200 RCX: 0000000000000000 RDX: fffffffffffffff8 RSI: 0000000000000200 RDI: ffffffff812f4f94 RBP: ffffc90003307a70 R08: 0000000000000000 R09: fffff52000660f90 R10: fffff52000660f90 R11: 1ffff92000660f8a R12: 1ffff92000660f50 R13: 1ffff11003e4b6da R14: 0000000000000246 R15: dffffc0000000000 FS: 00007f0e374ee6c0(0000) GS:ffff8880b8e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055555c049608 CR3: 000000007c9e6000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __local_bh_disable_ip+0xaf/0x190 kernel/softirq.c:361 local_bh_disable include/linux/bottom_half.h:20 [inline] fpregs_lock arch/x86/include/asm/fpu/api.h:72 [inline] restore_fpregs_from_user arch/x86/kernel/fpu/signal.c:285 [inline] __fpu_restore_sig arch/x86/kernel/fpu/signal.c:359 [inline] fpu__restore_sig+0x50a/0x1190 arch/x86/kernel/fpu/signal.c:493 restore_sigcontext arch/x86/kernel/signal.c:140 [inline] __ia32_sys_rt_sigreturn+0x649/0x790 arch/x86/kernel/signal.c:675 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: 0033:0x7f0e3658eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f0e374ee0e8 EFLAGS: 00000246 RAX: fffffffffffffffc RBX: 00007f0e367e5fa8 RCX: 00007f0e3658eec9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f0e367e5fa8 RBP: 00007f0e367e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0e367e6038 R14: 00007fff326807a0 R15: 00007fff32680888