CVE-2026-98254
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: swiotlb: use the adjusted address for the highmem page lookup swiotlb_bounce() reads the page frame number from the slot's recorded orig_addr, then advances orig_addr by tlb_offset to reach the address the caller asked about. The highmem branch mixes the two: the offset within the page comes from the adjusted address, the page from the value before it. Once the adjustment crosses a page boundary the pair no longer describes one location, and the whole copy lands one page below the intended one for a positive tlb_offset, one above for a negative one. DMA_FROM_DEVICE writes the device data over the wrong page and leaves the intended one stale, DMA_TO_DEVICE feeds the device from a page the mapping may not cover. Partial syncs through dma_sync_single_range_for_*() are what make tlb_offset non-zero. The branch test is picked the same way, so a slot recorded in lowmem can be adjusted into highmem and the lowmem path then hands a highmem address to phys_to_virt(). Take both from orig_addr once it is final and keep pfn in the branch that uses it. PhysHighMem() asks the question straight from the address, as dma-debug already does.
Gravité et risque d'exploitation
CVE-2026-98254 obtient un score CVSS de 7.8/10, soit une gravité élevée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.14 %, ce qui la place devant 2.8 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions <6e53b4d6afbde626255805d438cabb1cac482445, <5.11, <=6.12.*, <5.13, <aa4709813b29db89f2307f968db5d24925dcdeb1, 0, 5.12.14, 6.12.112, 5.10.47, 7.2.8, 5.13, e77b796eb9b7ca3c1c0d574d0c155f55b59ca8d5, <=6.18.*, <=7.2.*, 5f89468e2f060031cd89fd4287298e0eaf246bf6, <=*, <b7d7914a9ae3097e63d113007e4fb44d33d515b1, 6.18.54, <0219b72f5c209732b2f03a8cc0d7240b5e428a99, e6108147dd91b94d1979b110f265710c254c99d5, 7.3) est présent sur votre parc.
- Appliquez le correctif ou la version corrigée indiqués dans les références de l'éditeur.
- À défaut de correctif, limitez l'exposition (filtrage réseau, désactivation du composant).
- Automatisez la détection : les agents CVE Heimdall (gratuits, open source) corrèlent l'inventaire de vos serveurs avec la base CVE.