rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 ticks this GP) idle=c73c/1/0x4000000000000000 softirq=26357/26357 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7152/3:b..l rcu: (detected by 0, t=10503 jiffies, g=17877, q=511 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 5846 Comm: udevd Not tainted 6.15.0-syzkaller-13526-g7a912d04415b #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:timerqueue_add+0x1d2/0x200 lib/timerqueue.c:40 Code: 74 08 4c 89 ff e8 2e d6 c1 f6 4d 89 27 4d 85 e4 40 0f 95 c5 eb 07 e8 6d 63 5e f6 31 ed 4c 89 e7 4c 89 f6 e8 90 6d ff ff 89 e8 <48> 83 c4 18 5b 41 5c 41 5d 41 5e 41 5f 5d e9 86 48 ae f5 cc e8 45 RSP: 0018:ffffc90000a08cf0 EFLAGS: 00000086 RAX: 0000000000000001 RBX: 1ffff110170e4f82 RCX: 0000000000000000 RDX: 0000000000000018 RSI: ffff8880b8727c10 RDI: ffff888053b75340 RBP: 0000000000000001 R08: ffff888053b75357 R09: ffff888053b75340 R10: dffffc0000000000 R11: ffffed100a76ea6b R12: ffff888053b75340 R13: dffffc0000000000 R14: ffff8880b8727c10 R15: ffff8880b8727c18 FS: 00007f08971e7880(0000) GS:ffff888125d52000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c27fdf7 CR3: 00000000585e7000 CR4: 0000000000350ef0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:vma_next include/linux/mm.h:864 [inline] RIP: 0010:validate_mm+0xd0/0x4b0 mm/vma.c:636 Code: 98 00 00 00 01 00 00 00 48 89 df e8 9a 16 4a 09 4c 89 7c 24 20 49 8d 8f 28 01 00 00 48 89 4c 24 10 48 c1 e9 03 48 89 4c 24 28 <48> 8d 7c 24 60 48 c7 c6 ff ff ff ff e8 cf 76 49 09 48 85 c0 0f 84 RSP: 0018:ffffc900033a76c0 EFLAGS: 00000293 RAX: ffffffff821482c2 RBX: ffff8880314803c0 RCX: ffff888078399e00 RDX: 0000000000000000 RSI: 00007f089728a000 RDI: 00007f089728a000 RBP: ffffc900033a77f0 R08: ffff888078399e00 R09: 0000000000000004 R10: 0000000000000003 R11: 0000000000000000 R12: 00007f089728a000 R13: 000000000000002f R14: dffffc0000000000 R15: 0000000000000000 __split_vma+0x867/0x9b0 mm/vma.c:553 vms_gather_munmap_vmas+0x2de/0x12b0 mm/vma.c:1355 do_vmi_align_munmap+0x25d/0x420 mm/vma.c:1523 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1580 __vm_munmap+0x23b/0x3d0 mm/vma.c:3101 __do_sys_munmap mm/mmap.c:1084 [inline] __se_sys_munmap mm/mmap.c:1081 [inline] __x64_sys_munmap+0x60/0x70 mm/mmap.c:1081 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f0896b1e097 Code: 73 01 c3 48 8b 0d 61 2d 0d 00 f7 d8 64 89 01 48 83 c8 ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 b8 0b 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d 31 2d 0d 00 f7 d8 64 89 01 48 RSP: 002b:00007ffdc38b4ae8 EFLAGS: 00000246 ORIG_RAX: 000000000000000b RAX: ffffffffffffffda RBX: 0000558e923a18d0 RCX: 00007f0896b1e097 RDX: 0000558e9239e968 RSI: 0000000000000200 RDI: 00007f08971b4000 RBP: 0000000000000018 R08: 0000558e9239afd0 R09: 0000000000000003 R10: 0000000000000000 R11: 0000000000000246 R12: 0000558e923ae980 R13: 00007f089730e39c R14: 0000000000003000 R15: 0000000000000009 task:syz.2.332 state:R running task stack:23096 pid:7152 tgid:7152 ppid:5837 task_flags:0x400640 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6965 preempt_schedule+0xae/0xc0 kernel/sched/core.c:6989 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] filemap_map_pages+0x1118/0x1740 mm/filemap.c:3757 do_fault_around mm/memory.c:5568 [inline] do_read_fault mm/memory.c:5601 [inline] do_fault mm/memory.c:5744 [inline] do_pte_missing mm/memory.c:4251 [inline] handle_pte_fault mm/memory.c:6089 [inline] __handle_mm_fault+0x368a/0x5620 mm/memory.c:6232 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6401 faultin_page mm/gup.c:1186 [inline] __get_user_pages+0x1af4/0x30b0 mm/gup.c:1488 __get_user_pages_locked mm/gup.c:1754 [inline] get_dump_page+0x1ac/0x3f0 mm/gup.c:2258 dump_user_range+0x1de/0xc70 fs/coredump.c:1180 elf_core_dump+0x32ed/0x3900 fs/binfmt_elf.c:2075 do_coredump+0x2809/0x3440 fs/coredump.c:950 get_signal+0x1109/0x1340 kernel/signal.c:3019 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline] irqentry_exit_to_user_mode+0x81/0x120 kernel/entry/common.c:184 exc_general_protection+0x171/0x200 arch/x86/kernel/traps.c:792 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617 RIP: 0033:0x7f6c1af8e931 RSP: 002b:0000200000000450 EFLAGS: 00010217 RAX: 0000000000000000 RBX: 00007f6c1b1b5fa0 RCX: 00007f6c1af8e929 RDX: 0000200000000480 RSI: 0000200000000450 RDI: 0000000000104200 RBP: 00007f6c1b010b39 R08: 0000200000000580 R09: 0000200000000580 R10: 0000200000000540 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f6c1b1b5fa0 R15: 00007ffe85837758 rcu: rcu_preempt kthread timer wakeup didn't happen for 10502 jiffies! g17877 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=1 timer-softirq=13766 rcu: rcu_preempt kthread starved for 10503 jiffies! g17877 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 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:I stack:27320 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5396 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6785 __schedule_loop kernel/sched/core.c:6863 [inline] schedule+0x165/0x360 kernel/sched/core.c:6878 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x711/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245