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CVE-2026-64590

Vulnérabilité non évaluée dans Linux (Linux)

CVSS 0.0 · Non évaluée
EPSS 0.2%
Linux•Linux•Versions : <=6.1.*, <=6.12.*, 6.18.39, 5.15.217, <d6552f5cff795d60e629f37513ecf23d88fd2f82, <34696563461c9a23177feb6d8aff43f4c0510278, 0, <dd7f1e572f44d3d039dc77e3989f537196c3bf52, <=7.1.*, 7.1.4, 5.6, <=5.10.*, <=6.6.*, 5.10.266, <0db56e7eae932f8e2f3eb44ad1a63633d8f504f8, 284562e1f34874e267d4f499362c3816f8f6bc3f, <504e2b4ab97a51d56d966cd36d0997ad30b65b2d, <=6.18.*, <4a7c644e632741c2a3116a0d3da6c11de957a6ba, 6.1.184, <0449a6583c0ee76778d314e4e82f166fc97fa9d8, <5.6, <=*, <=5.15.*, <01126abc11bcc6a45b664293b0b5df715be911d7, 6.12.96, 6.6.148, 7.2

Description

In the Linux kernel, the following vulnerability has been resolved: dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning When CONFIG_DMA_API_DEBUG_SG is enabled, importing a udmabuf into a DRM driver (e.g. amdgpu for video playback in GNOME Videos / Showtime) triggers a spurious warning: DMA-API: amdgpu 0000:03:00.0: cacheline tracking EEXIST, \ overlapping mappings aren't supported WARNING: kernel/dma/debug.c:619 at add_dma_entry+0x473/0x5f0 The call chain is: amdgpu_cs_ioctl -> amdgpu_ttm_backend_bind -> dma_buf_map_attachment -> [udmabuf] map_udmabuf -> get_sg_table -> dma_map_sgtable(dev, sg, direction, 0) // attrs=0 -> debug_dma_map_sg -> add_dma_entry -> EEXIST This happens because udmabuf builds a per-page scatter-gather list via sg_set_folio(). When begin_cpu_udmabuf() has already created an sg table mapped for the misc device, and an importer such as amdgpu maps the same pages for its own device via map_udmabuf(), the DMA debug infrastructure sees two active mappings whose physical addresses share cacheline boundaries and warns about the overlap. The DMA_ATTR_SKIP_CPU_SYNC flag suppresses this check in add_dma_entry() because it signals that no CPU cache maintenance is performed at map/unmap time, making the cacheline overlap harmless. All other major dma-buf exporters already pass this flag: - drm_gem_map_dma_buf() passes DMA_ATTR_SKIP_CPU_SYNC - amdgpu_dma_buf_map() passes DMA_ATTR_SKIP_CPU_SYNC The CPU sync at map/unmap time is also redundant for udmabuf: begin_cpu_udmabuf() and end_cpu_udmabuf() already perform explicit cache synchronization via dma_sync_sgtable_for_cpu/device() when CPU access is requested through the dma-buf interface. Pass DMA_ATTR_SKIP_CPU_SYNC to dma_map_sgtable() and dma_unmap_sgtable() in udmabuf to suppress the spurious warning and skip the redundant sync.

Gravité et risque d'exploitation

CVE-2026-64590 obtient un score CVSS de 0.0/10, soit une gravité non évaluée. Selon le modèle EPSS, la probabilité qu'elle soit exploitée dans les 30 prochains jours est de 0.17 %, ce qui la place devant 5.3 % des CVE référencées.

Que faire ?

  • Vérifiez si Linux (versions <=6.1.*, <=6.12.*, 6.18.39, 5.15.217, <d6552f5cff795d60e629f37513ecf23d88fd2f82, <34696563461c9a23177feb6d8aff43f4c0510278, 0, <dd7f1e572f44d3d039dc77e3989f537196c3bf52, <=7.1.*, 7.1.4, 5.6, <=5.10.*, <=6.6.*, 5.10.266, <0db56e7eae932f8e2f3eb44ad1a63633d8f504f8, 284562e1f34874e267d4f499362c3816f8f6bc3f, <504e2b4ab97a51d56d966cd36d0997ad30b65b2d, <=6.18.*, <4a7c644e632741c2a3116a0d3da6c11de957a6ba, 6.1.184, <0449a6583c0ee76778d314e4e82f166fc97fa9d8, <5.6, <=*, <=5.15.*, <01126abc11bcc6a45b664293b0b5df715be911d7, 6.12.96, 6.6.148, 7.2) 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.

Références

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