rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=116c/1/0x4000000000000000 softirq=703/704 fqs=0 rcu: (detected by 0, t=10002 jiffies, g=885, q=664 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 547 Comm: syz.1.67 Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:vga_put drivers/pci/vgaarb.c:-1 [inline] RIP: 0010:vga_arb_release+0x1ec/0x950 drivers/pci/vgaarb.c:1455 Code: 6a de 97 fe e9 37 03 00 00 48 8b 45 88 42 80 3c 38 00 74 08 4c 89 ef e8 d2 4b ee fe 4d 8b 65 00 4d 85 e4 74 07 e8 44 de 97 fe 15 4c 8b 25 ab ed b0 05 4d 85 e4 0f 84 04 01 00 00 e8 2d de 97 RSP: 0018:ffffc9000e0f78f8 EFLAGS: 00000093 RAX: ffffffff82ee206c RBX: 0000000000000000 RCX: ffff888119522600 RDX: 0000000000000000 RSI: 0000000000000802 RDI: ffffffff889f0e40 RBP: ffffc9000e0f7980 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52001c1ef0c R12: ffff88810e262000 R13: ffff888117be2818 R14: ffff888117be2824 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8881f6f00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000001000 CR3: 0000000117b1a000 CR4: 00000000003526b0 Call Trace: __fput+0x1fb/0xa00 fs/file_table.c:429 ____fput+0x20/0x30 fs/file_table.c:457 task_work_run+0x1e0/0x250 kernel/task_work.c:240 exit_task_work include/linux/task_work.h:43 [inline] do_exit+0x9bc/0x2630 kernel/exit.c:953 do_group_exit+0x22a/0x300 kernel/exit.c:1095 get_signal+0x139d/0x14f0 kernel/signal.c:2933 arch_do_signal_or_restart+0x96/0x720 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:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f87ed58f6c9 Code: Unable to access opcode bytes at 0x7f87ed58f69f. RSP: 002b:00007f87ebfe30e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f87ed7e5fa8 RCX: 00007f87ed58f6c9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f87ed7e5fa8 RBP: 00007f87ed7e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f87ed7e6038 R14: 00007ffec1798220 R15: 00007ffec1798308 rcu: rcu_preempt kthread starved for 10002 jiffies! g885 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:0 pid:18 tgid:18 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5945 [inline] __schedule+0x1322/0x1df0 kernel/sched/core.c:7791 __schedule_loop kernel/sched/core.c:7872 [inline] schedule+0xc6/0x240 kernel/sched/core.c:7887 schedule_timeout+0x139/0x3a0 kernel/time/timer.c:2619 rcu_gp_fqs_loop+0x2f2/0x12f0 kernel/rcu/tree.c:2053 rcu_gp_kthread+0x99/0x380 kernel/rcu/tree.c:2255 kthread+0x2ca/0x370 kernel/kthread.c:389 ret_from_fork+0x67/0xa0 arch/x86/kernel/process.c:153 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 548 Comm: syz.1.67 Not tainted syzkaller #0 0b5ffdee5fcd2f7749818d1ff954e9c21353764e Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:csd_lock_wait kernel/smp.c:349 [inline] RIP: 0010:smp_call_function_many_cond+0xa24/0xf30 kernel/smp.c:884 Code: 75 79 41 8b 5d 00 89 de 83 e6 01 31 ff e8 f4 2f 0a 00 83 e3 01 48 bb 00 00 00 00 00 fc ff df 75 07 e8 a0 2b 0a 00 eb 38 f3 90 <41> 0f b6 04 1e 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 84 2b RSP: 0018:ffffc9000e11f600 EFLAGS: 00000293 RAX: ffffffff817bd32c RBX: dffffc0000000000 RCX: ffff888119525f00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000e11f728 R08: ffff8881f6e50e97 R09: 1ffff1103edca1d2 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8881f6e50e88 R13: ffff8881f6f720a8 R14: 1ffff1103edee415 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff8881f6e00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f87ebfc2d58 CR3: 00000001178a2000 CR4: 00000000003526b0 Call Trace: on_each_cpu_cond_mask+0x44/0x90 kernel/smp.c:1051 native_flush_tlb_multi+0x14c/0x220 arch/x86/mm/tlb.c:-1 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:985 [inline] flush_tlb_mm_range+0x35b/0x4f0 arch/x86/mm/tlb.c:1073 tlb_flush arch/x86/include/asm/tlb.h:20 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:465 [inline] tlb_flush_mmu+0x1e9/0xaf0 mm/mmu_gather.c:372 tlb_finish_mmu+0xcf/0x1d0 mm/mmu_gather.c:465 exit_mmap+0x405/0xb60 mm/mmap.c:1976 __mmput+0x93/0x320 kernel/fork.c:1349 mmput+0x55/0x170 kernel/fork.c:1372 exit_mm kernel/exit.c:574 [inline] do_exit+0x918/0x2630 kernel/exit.c:940 do_group_exit+0x22a/0x300 kernel/exit.c:1095 get_signal+0x139d/0x14f0 kernel/signal.c:2933 arch_do_signal_or_restart+0x96/0x720 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:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x58/0xb0 kernel/entry/common.c:218 do_syscall_64+0x64/0xf0 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x76/0x7e RIP: 0033:0x7f87ed58f6c9 Code: Unable to access opcode bytes at 0x7f87ed58f69f. RSP: 002b:00007f87ebfc20e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f87ed7e6098 RCX: 00007f87ed58f6c9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f87ed7e6098 RBP: 00007f87ed7e6090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f87ed7e6128 R14: 00007ffec1798220 R15: 00007ffec1798308