{
  "affected": [
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.1.187-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:13",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.96-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:14",
        "name": "linux"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "7.1.4-1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "ecosystem_specific": {
        "urgency": "not yet assigned"
      },
      "package": {
        "ecosystem": "Debian:12",
        "name": "linux-6.12"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "6.12.100-1~deb12u1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "details": "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    -\u003e amdgpu_ttm_backend_bind     -\u003e dma_buf_map_attachment      -\u003e [udmabuf] map_udmabuf -\u003e get_sg_table       -\u003e dma_map_sgtable(dev, sg, direction, 0)  // attrs=0        -\u003e debug_dma_map_sg -\u003e add_dma_entry -\u003e 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.",
  "id": "DEBIAN-CVE-2026-64590",
  "modified": "2026-09-14T16:47:41.293834050Z",
  "published": "2026-08-06T08:16:34.357Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://security-tracker.debian.org/tracker/CVE-2026-64590"
    }
  ],
  "upstream": [
    "CVE-2026-64590"
  ]
}