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CVE-2026-45944: Linux, състезание за ресурс

7.5

CVSS 3.1

Няма данни

Вероятност да бъде експлоатирана в следващите 30 дни (EPSS)

Няма потвърждение

Атакува се

Няма данни

Време до експлоатация

Атакува се локално, при специфични условия, с администраторски права и без действие от потребителя.

CVE радар: още уязвимости от този вид

  • Експлоатация: няма данни за експлоатация
  • Атаката не може да се автоматизира

Описание

Оригинално описание

In the Linux kernel, the following vulnerability has been resolved: iommu/vt-d: Clear Present bit before tearing down context entry When tearing down a context entry, the current implementation zeros the entire 128-bit entry using multiple 64-bit writes. This creates a window where the hardware can fetch a "torn" entry — where some fields are already zeroed while the 'Present' bit is still set — leading to unpredictable behavior or spurious faults. While x86 provides strong write ordering, the compiler may reorder writes to the two 64-bit halves of the context entry. Even without compiler reordering, the hardware fetch is not guaranteed to be atomic with respect to multiple CPU writes. Align with the "Guidance to Software for Invalidations" in the VT-d spec (Section 6.5.3.3) by implementing the recommended ownership handshake: 1. Clear only the 'Present' (P) bit of the context entry first to signal the transition of ownership from hardware to software. 2. Use dma_wmb() to ensure the cleared bit is visible to the IOMMU. 3. Perform the required cache and context-cache invalidation to ensure hardware no longer has cached references to the entry. 4. Fully zero out the entry only after the invalidation is complete. Also, add a dma_wmb() to context_set_present() to ensure the entry is fully initialized before the 'Present' bit becomes visible.

Засегнати продукти

  • Linux Linux: ba39592764ed20cee09aae5352e603a27bf56b0d преди 61fa8546e39331103d6ce01575699c577d83e000; ba39592764ed20cee09aae5352e603a27bf56b0d преди ab4aeab2d630e68be60ccbea3fcf76fa7c281a18; ba39592764ed20cee09aae5352e603a27bf56b0d преди c716a59e9977d751e5eb54bcfa6a80124cb5067b; ba39592764ed20cee09aae5352e603a27bf56b0d преди d2138abc8f0a7fce4101b7229b43b06811ed083d; ba39592764ed20cee09aae5352e603a27bf56b0d преди a922dbafb4a674d958d702038232d09a30daf770; ba39592764ed20cee09aae5352e603a27bf56b0d преди c1e4f1dccbe9d7656d1c6872ebeadb5992d0aaa2
  • Linux Linux: 2.6.24; преди 2.6.24; 6.1.191 до 6.1.*; 6.6.160 до 6.6.*; 6.12.97 до 6.12.*; 6.18.14 до 6.18.*; 6.19.4 до 6.19.*; от 7.0 нататък

Вид слабост

История

  • 27 май 2026 Публикувано

Други уязвимости в Linux Linux

Първоизточници

CVE-2026-45944: Linux, състезание за ресурс | freedomonline.bg