CVE-2026-89917— KVM arm64 VNCR TLB失效与vcpu_put竞态
一分钟漏洞结论
影响对象
Linux Linux
利用判断
尚无明确在野利用证据，仍需结合暴露面评估
建议动作
优先检查厂商安全公告和参考链接中的修复版本；无法立即升级时，限制受影响服务暴露并加强监测。
在 Linux 内核中，以下漏洞已得到修复： KVM: arm64：处理 VNCR TLB 无效化与 vcpu_put() 中 VNCR 解映射之间的竞态条件 VNCR TLB 无效化操作总是在 MMU 锁保护下执行，而 vcpu_put() 在解映射 VNCR 页时并不持有该锁。 问题在于：TLB 无效化路径通过检查 vncr_tlb::cpu 字段（判断 cpu != -1）来决定是否需要执行解映射，存在典型的 TOCTOU（Time-of-Check to Time-of-Use）竞态；而 this_cpu_
影响版本矩阵 8
| 厂商 | 产品 | 版本范围 | 状态 |
|---|---|---|---|
| Linux | Linux | 7270cc9157f474dfc46750a34c9d7defc686b2eb< 5cbd8761d001c11ada73b1753d772c4745a70e72 |
affected |
7270cc9157f474dfc46750a34c9d7defc686b2eb< 9065c1261f8a05c6a7a2d90048c7c0665ab2896d |
affected | ||
7270cc9157f474dfc46750a34c9d7defc686b2eb< 38640bc32be3fcf9526d477155bc19d3f146231f |
affected | ||
6.16 |
affected | ||
< 6.16 |
unaffected | ||
6.18.52≤ 6.18.* |
unaffected | ||
7.2.5≤ 7.2.* |
unaffected | ||
7.3-rc1≤ * |
unaffected |
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一、 漏洞 CVE-2026-89917 基础信息
漏洞信息
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Vulnerability Title
KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping
来源: CVE Program / CVE List V5
Vulnerability Description
In the Linux kernel, the following vulnerability has been resolved:
KVM: arm64: Handle VNCR TLB invalidation race with vcpu_put() VNCR unmapping
While VNCR TLB invalidation always occurs under the MMU lock,
vcpu_put() doesn't, while it unmaps the VNCR page.
The problem is that the invalidation evaluates vncr_tlb::cpu to
decide whether an unmapping needs to take place (cpu != -1) before
performing it. On the other hand, this_cpu_reset_vncr_fixmap()
unconditionally unmaps if L1_VNCR_MAPPED is set.
These two obviously can race, with a TOCTOU pattern on the TLBI
path, and a BUG_ON() on the vcpu_put() path. And the two can end-up
calling vncr_fixmap(-1), with extra lethal effects.
Move the reset of vncr_tlb::cpu to -1 to a common function, and make
this update atomic so that only a single thread can reset the field
and perform the corresponding unmap. The vcpu_put() still need to
unconditionally unmap the current VNCR to close another ugly race.
Finally, the assignment of vncr_tlb::cpu is moved to be kept in sync
with the actual mapping, similar to L1_VNCR_MAPPED being set.
来源: CVE Program / CVE List V5
CVSS Information
N/A
来源: CVE Program / CVE List V5
Vulnerability Type
N/A
来源: CVE Program / CVE List V5
受影响产品
二、漏洞 CVE-2026-89917 的公开POC
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CVE-2026-89917 其他参考 (3)
同批安全公告 · Linux · 2026-09-16 · 共 276 条
| CVE-2026-90048 | 9.8 CRITICAL | Linux内核NTFS3文件系统越界写漏洞 |
| CVE-2026-90012 | 9.8 CRITICAL | SPI DMA映射所有权修复 |
| CVE-2026-89970 | 9.8 CRITICAL | NVM Target SQ拆除时超时工作未同步 |
| CVE-2026-89857 | 9.8 CRITICAL | QLogic qla2xxx NVMe LS拒绝竞态条件漏洞 |
| CVE-2026-89969 | 9.8 CRITICAL | Linux内核 nvmet-tcp 越界写入漏洞 |
| CVE-2026-89847 | 9.8 CRITICAL | qla2xxx SCSI驱动异步IOCB超时双重完成漏洞 |
| CVE-2026-89972 | 9.8 CRITICAL | NVMe驱动错误路径SRCU宽限期缺失漏洞 |
| CVE-2026-89990 | 9.8 CRITICAL | Ceph ceph_mds_check_access 互斥锁缺失漏洞 |
| CVE-2026-90036 | 9.8 CRITICAL | Linux NFSd 阻塞锁收割时释放后使用漏洞 |
| CVE-2026-90038 | 9.8 CRITICAL | Linux内核NFSD导出撤销后使用漏洞 |
| CVE-2026-90037 | 9.8 CRITICAL | Linux内核NFSD close_lru释放后使用漏洞 |
| CVE-2026-89788 | 9.8 CRITICAL | Linux kernel ksmbd 释放后使用漏洞 |
| CVE-2026-89783 | 9.8 CRITICAL | Linux内核 xfrm6 越界写入漏洞 |
| CVE-2026-90042 | 9.8 CRITICAL | Ceph 虚拟内存分配缓冲区文件名解密漏洞 |
| CVE-2026-89778 | 9.8 CRITICAL | isofs 空 zisofs 块页面数组越界访问漏洞 |
| CVE-2026-89915 | 9.3 CRITICAL | KVM arm64 移除虚拟机级 VNCR 映射计数器 |
| CVE-2026-90049 | 9.3 CRITICAL | 内核网络子系统中skb_zerocopy处理中的缺陷 |
| CVE-2026-89775 | 9.3 CRITICAL | KVM arm64 VNCR TLB大小计算漏洞 |
| CVE-2026-89916 | 9.3 CRITICAL | KVM arm64 VNCR失效重试漏洞 |
| CVE-2026-89930 | 9.3 CRITICAL | KVM嵌套虚拟化本地TLB刷新漏洞 |
显示前 20 条，共 276 条。 查看全部 → →
IV. Related Vulnerabilities
V. Comments for CVE-2026-89917
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