syzbot

rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	1-...!: (0 ticks this GP) idle=09cc/1/0x4000000000000000 softirq=47926/47926 fqs=0
rcu: 	(detected by 0, t=10502 jiffies, g=41685, q=335 ncpus=2)
Sending NMI from CPU 0 to CPUs 1:
NMI backtrace for cpu 1
CPU: 1 UID: 0 PID: 11640 Comm: syz.1.2181 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:_raw_spin_lock_irqsave+0xbb/0xf0 kernel/locking/spinlock.c:162
Code: f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 75 08 e8 a9 bf 64 f6 48 83 c4 08 48 89 df e8 fd 63 65 f6 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 65 48 8b 05 d5 ff 11 07 48 3b 44 24 48 75
RSP: 0018:ffffc90000a08c00 EFLAGS: 00000046
RAX: 0383113458fcb300 RBX: ffffffff99794dd0 RCX: dffffc0000000000
RDX: 0000000000000001 RSI: 0000000000000004 RDI: ffffc90000a08b80
RBP: ffffc90000a08c98 R08: 0000000000000003 R09: 0000000000000004
R10: dffffc0000000000 R11: fffff52000141170 R12: dffffc0000000000
R13: dffffc0000000000 R14: 0000000000000012 R15: 1ffff92000141180
FS:  00007f7a233c76c0(0000) GS:ffff88812648a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000200000000240 CR3: 00000000779b5000 CR4: 0000000000350ef0
Call Trace:
 <IRQ>
 debug_object_deactivate+0x9a/0x250 lib/debugobjects.c:873
 debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline]
 debug_deactivate+0x1d/0x200 kernel/time/hrtimer.c:483
 __run_hrtimer kernel/time/hrtimer.c:1745 [inline]
 __hrtimer_run_queues+0x2b0/0xc60 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702
RIP: 0010:lock_is_held_type+0x137/0x190 kernel/locking/lockdep.c:5945
Code: 01 75 44 48 c7 04 24 00 00 00 00 9c 8f 04 24 f7 04 24 00 02 00 00 75 4c 41 f7 c4 00 02 00 00 74 01 fb 65 48 8b 05 59 8e 14 07 <48> 3b 44 24 08 75 43 89 d8 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f
RSP: 0018:ffffc9000de0f548 EFLAGS: 00000206
RAX: 0383113458fcb300 RBX: 0000000000000001 RCX: 0383113458fcb300
RDX: ffff8880347e1e40 RSI: ffffffff8d6f525f RDI: ffffffff8b9eea60
RBP: 00000000ffffffff R08: ffffea00011ea9c7 R09: 1ffffd400023d538
R10: dffffc0000000000 R11: fffff9400023d539 R12: 0000000000000246
R13: ffff8880347e1e40 R14: ffffffff8dd3b160 R15: 0000000000000001
 xa_entry include/linux/xarray.h:1226 [inline]
 xas_next_entry+0x202/0x3d0 include/linux/xarray.h:1731
 next_uptodate_folio+0x32/0x5d0 mm/filemap.c:3639
 filemap_map_pages+0x11ea/0x1c60 mm/filemap.c:3856
 do_fault_around mm/memory.c:5656 [inline]
 do_read_fault mm/memory.c:5689 [inline]
 do_fault mm/memory.c:5832 [inline]
 do_pte_missing mm/memory.c:4361 [inline]
 handle_pte_fault mm/memory.c:6177 [inline]
 __handle_mm_fault+0x347e/0x5400 mm/memory.c:6318
 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487
 faultin_page mm/gup.c:1126 [inline]
 __get_user_pages+0x165c/0x2a00 mm/gup.c:1428
 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860
 __mm_populate+0x24c/0x380 mm/gup.c:1963
 mm_populate include/linux/mm.h:3466 [inline]
 vm_mmap_pgoff+0x387/0x4d0 mm/util.c:585
 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: 0033:0x7f7a2258eec9
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:00007f7a233c7038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009
RAX: ffffffffffffffda RBX: 00007f7a227e5fa0 RCX: 00007f7a2258eec9
RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000200000000000
RBP: 00007f7a22611f91 R08: ffffffffffffffff R09: 0000000032cc0000
R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f7a227e6038 R14: 00007f7a227e5fa0 R15: 00007ffe237622a8
 </TASK>
rcu: rcu_preempt kthread starved for 10502 jiffies! g41685 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:27320 pid:16    tgid:16    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x439/0x7d0 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 0 UID: 0 PID: 11659 Comm: syz.3.2189 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025
RIP: 0010:native_pause arch/x86/include/asm/vdso/processor.h:13 [inline]
RIP: 0010:cpu_relax arch/x86/include/asm/vdso/processor.h:18 [inline]
RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline]
RIP: 0010:smp_call_function_many_cond+0xd31/0x12d0 kernel/smp.c:877
Code: 00 00 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 96 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 41 6f 0b 00 eb 38 <f3> 90 42 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8
RSP: 0018:ffffc9000ddcf540 EFLAGS: 00000246
RAX: ffffffff81b3103b RBX: 1ffff11017127ff5 RCX: 0000000000080000
RDX: ffffc9000c0eb000 RSI: 000000000007ffff RDI: 0000000000080000
RBP: ffffc9000ddcf6c0 R08: ffffffff8f5bed37 R09: 1ffffffff1eb7da6
R10: dffffc0000000000 R11: fffffbfff1eb7da7 R12: ffff8880b893ffa8
R13: dffffc0000000000 R14: ffff8880b883b200 R15: 0000000000000001
FS:  00007fcd863a06c0(0000) GS:ffff88812638a000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f4cf2b156c0 CR3: 00000000526d8000 CR4: 0000000000350ef0
Call Trace:
 <TASK>
 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1043
 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline]
 flush_tlb_multi arch/x86/mm/tlb.c:1361 [inline]
 flush_tlb_mm_range+0x6b1/0x12d0 arch/x86/mm/tlb.c:1451
 tlb_flush arch/x86/include/asm/tlb.h:23 [inline]
 tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline]
 tlb_flush_mmu+0x1a7/0x680 mm/mmu_gather.c:403
 tlb_finish_mmu+0xc3/0x1d0 mm/mmu_gather.c:497
 vms_clear_ptes+0x42c/0x540 mm/vma.c:1235
 vms_complete_munmap_vmas+0x206/0x8a0 mm/vma.c:1277
 do_vmi_align_munmap+0x364/0x440 mm/vma.c:1536
 do_vmi_munmap+0x253/0x2e0 mm/vma.c:1584
 __vm_munmap+0x207/0x380 mm/vma.c:3156
 __do_sys_munmap mm/mmap.c:1080 [inline]
 __se_sys_munmap mm/mmap.c:1077 [inline]
 __x64_sys_munmap+0x60/0x70 mm/mmap.c:1077
 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: 0033:0x7fcd8558ef57
Code: 00 00 00 48 c7 c2 a8 ff ff ff f7 d8 64 89 02 48 c7 c0 ff ff ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 0b 00 00 00 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:00007fcd8639fe18 EFLAGS: 00000246 ORIG_RAX: 000000000000000b
RAX: ffffffffffffffda RBX: 0000000000080000 RCX: 00007fcd8558ef57
RDX: 0000000000000000 RSI: 0000000008400000 RDI: 00007fcd7b200000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000593
R10: 00000000000003ca R11: 0000000000000246 R12: 0000000000000003
R13: 00007fcd8639fef0 R14: 00007fcd8639feb0 R15: 00007fcd7b200000
 </TASK>
vkms_vblank_simulate: vblank timer overrun