CVE-2022-50224 Information

Jun 19, 2025 cve

Description

In the Linux kernel the following vulnerability has been resolved:

KVM: x86/mmu: Treat NX as a valid SPTE bit for NPT

Treat the NX bit as valid when using NPT as KVM will set the NX bit when the NX huge page mitigation is enabled (mindblowing) and trigger the WARN that fires on reserved SPTE bits being set.

KVM has required NX support for SVM since commit b26a71a1a5b9 (\KVM: SVM: Refuse to load kvm_amd if NX support is not available) for exactly this reason but apparently it never occurred to anyone to actually test NPT with the mitigation enabled.

————[ cut here ]———— spte = 0x800000018a600ee7 level = 2 rsvd bits = 0x800f0000001fe000 WARNING: CPU: 152 PID: 15966 at arch/x86/kvm/mmu/spte.c:215 make_spte+0x327/0x340 [kvm] Hardware name: Google Inc. Arcadia_IT_80/Arcadia_IT_80 BIOS 10.48.0 01/27/2022 RIP: 0010:make_spte+0x327/0x340 [kvm] Call Trace: tdp_mmu_map_handle_target_level+0xc3/0x230 [kvm] kvm_tdp_mmu_map+0x343/0x3b0 [kvm] direct_page_fault+0x1ae/0x2a0 [kvm] kvm_tdp_page_fault+0x7d/0x90 [kvm] kvm_mmu_page_fault+0xfb/0x2e0 [kvm] npf_interception+0x55/0x90 [kvm_amd] svm_invoke_exit_handler+0x31/0xf0 [kvm_amd] svm_handle_exit+0xf6/0x1d0 [kvm_amd] vcpu_enter_guest+0xb6d/0xee0 [kvm] ? kvm_pmu_trigger_event+0x6d/0x230 [kvm] vcpu_run+0x65/0x2c0 [kvm] kvm_arch_vcpu_ioctl_run+0x355/0x610 [kvm] kvm_vcpu_ioctl+0x551/0x610 [kvm] __se_sys_ioctl+0x77/0xc0 __x64_sys_ioctl+0x1d/0x20 do_syscall_64+0x44/0xa0 entry_SYSCALL_64_after_hwframe+0x46/0xb0 —[ end trace 0000000000000000 ]—

Reference

https://git.kernel.org/stable/c/6271f2854b9233702e236e576b885a876dde4889 https://git.kernel.org/stable/c/6c6ab524cfae0799e55c82b2c1d61f1af0156f8d

CNNVD-202506-2514 (Published: 2025-06-18)

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