CVE-2026-90244
Vulnérabilité élevée dans Linux (Linux)
Description
In the Linux kernel, the following vulnerability has been resolved: iommu/dma: Restore locking around msi_page_list Unlike a group's default domain, which is always freshly allocated and privately owned (iommu_group_alloc_default_domain()), VFIO type1's legacy container merges any newly attached group into an existing domain whenever their iommu_ops and cache-coherency enforcement match. iommu_dma_get_msi_page() only asserts the caller's own group mutex is held (iommu_group_mutex_assert()). On an IOMMU that publishes IOMMU_RESV_SW_MSI, e.g. ARM SMMU, a VM with two such devices assigned through the legacy container can have their guest drivers probe and allocate MSIs in parallel; each host-side VFIO_DEVICE_SET_IRQS lands on a different device fd and group mutex, but both devices' domains are the same merged domain, so both can enter iommu_dma_get_msi_page() concurrently and corrupt msi_page_list. commit 288683c92b1a ("iommu: Make iommu_dma_prepare_msi() into a generic operation") dropped the prior msi_prepare_lock on the reasoning that "each iommu_domain is unique to a group," which holds for default domains but not this VFIO type1 case. Restore the static lock, since it's only guarding a corner case and will likely never be contended. iommufd avoids the equivalent problem by having its own callers (iommufd_sw_map_msi()) take a ctx-wide sw_msi_lock before ever reaching the shared list. VFIO type1 can't mirror that since it dispatches to iommu_dma_sw_msi() which is outside VFIO's jurisdiction.
Gravité et risque d'exploitation
CVE-2026-90244 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 0.17 %, ce qui la place devant 6.4 % des CVE référencées.
Que faire ?
- Vérifiez si Linux (versions 6.18.52, 7.2.6, <2af1e99ec14d226d66ceb9f16c663ee2568e6676, <=*, <e3c53e9173a47d5ce1fae020f2c6b1fb3c1123c2, <=7.2.*, <6.15, <=6.18.*, 0, <5a9e89ea34e0e34ac5d7e949042d665533549e40, 6.15, 288683c92b1abc32277c83819bea287af614d239, 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.