{ "schema_version": "1.6.1", "id": "RPI-CVE-2026-64590", "modified": "2026-10-07T17:22:01Z", "upstream": [ "CVE-2026-64590" ], "published": "2026-08-06T07:14:03Z", "summary": "dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning", "details": "In the Linux kernel, the following vulnerability has been resolved:\n\ndma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning\n\nWhen CONFIG_DMA_API_DEBUG_SG is enabled, importing a udmabuf into a DRM\ndriver (e.g. amdgpu for video playback in GNOME Videos / Showtime)\ntriggers a spurious warning:\n\n DMA-API: amdgpu 0000:03:00.0: cacheline tracking EEXIST, \\\n overlapping mappings aren't supported\n WARNING: kernel/dma/debug.c:619 at add_dma_entry+0x473/0x5f0\n\nThe call chain is:\n\n amdgpu_cs_ioctl\n -> amdgpu_ttm_backend_bind\n -> dma_buf_map_attachment\n -> [udmabuf] map_udmabuf -> get_sg_table\n -> dma_map_sgtable(dev, sg, direction, 0) // attrs=0\n -> debug_dma_map_sg -> add_dma_entry -> EEXIST\n\nThis happens because udmabuf builds a per-page scatter-gather list via\nsg_set_folio(). When begin_cpu_udmabuf() has already created an sg\ntable mapped for the misc device, and an importer such as amdgpu maps\nthe same pages for its own device via map_udmabuf(), the DMA debug\ninfrastructure sees two active mappings whose physical addresses share\ncacheline boundaries and warns about the overlap.\n\nThe DMA_ATTR_SKIP_CPU_SYNC flag suppresses this check in\nadd_dma_entry() because it signals that no CPU cache maintenance is\nperformed at map/unmap time, making the cacheline overlap harmless.\n\nAll other major dma-buf exporters already pass this flag:\n - drm_gem_map_dma_buf() passes DMA_ATTR_SKIP_CPU_SYNC\n - amdgpu_dma_buf_map() passes DMA_ATTR_SKIP_CPU_SYNC\n\nThe CPU sync at map/unmap time is also redundant for udmabuf:\nbegin_cpu_udmabuf() and end_cpu_udmabuf() already perform explicit\ncache synchronization via dma_sync_sgtable_for_cpu/device() when CPU\naccess is requested through the dma-buf interface.\n\nPass DMA_ATTR_SKIP_CPU_SYNC to dma_map_sgtable() and\ndma_unmap_sgtable() in udmabuf to suppress the spurious warning and\nskip the redundant sync.", "affected": [ { "package": { "ecosystem": "Raspberry Pi OS:12", "name": "linux" }, "versions": [ "1:6.1.47-1+rpt4", "1:6.12.34-1+rpt1~bookworm", "1:6.12.47-1+rpt1~bookworm", "1:6.12.62-1+rpt1~bookworm", "1:6.12.75-1+rpt1~bookworm", "1:6.12.87-1+rpt1~bookworm", "1:6.12.93-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.1.0-rpi3-rpi-2712", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v6", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v7l", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.1.0-rpi3-rpi-v8", "binary_version": "1:6.1.47-1+rpt4" }, { "binary_name": "linux-image-6.12.34+rpt-rpi-2712", "binary_version": "1:6.12.34-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.34+rpt-rpi-v8", "binary_version": "1:6.12.34-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.34+rpt-rpi-v8-rt", "binary_version": "1:6.12.34-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.47+rpt-rpi-2712", "binary_version": "1:6.12.47-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.47+rpt-rpi-v8", "binary_version": "1:6.12.47-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.47+rpt-rpi-v8-rt", "binary_version": "1:6.12.47-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.62+rpt-rpi-2712", "binary_version": "1:6.12.62-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.62+rpt-rpi-v8", "binary_version": "1:6.12.62-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.62+rpt-rpi-v8-rt", "binary_version": "1:6.12.62-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.75+rpt-rpi-2712", "binary_version": "1:6.12.75-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.75+rpt-rpi-v8", "binary_version": "1:6.12.75-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.75+rpt-rpi-v8-rt", "binary_version": "1:6.12.75-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.87+rpt-rpi-2712", "binary_version": "1:6.12.87-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.87+rpt-rpi-v8", "binary_version": "1:6.12.87-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.87+rpt-rpi-v8-rt", "binary_version": "1:6.12.87-1+rpt1~bookworm" }, { "binary_name": "linux-image-6.12.93+rpt-rpi-2712", "binary_version": "1:6.12.93-1+rpt1" }, { "binary_name": "linux-image-6.12.93+rpt-rpi-v8", "binary_version": "1:6.12.93-1+rpt1" }, { "binary_name": "linux-image-6.12.93+rpt-rpi-v8-rt", "binary_version": "1:6.12.93-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.1.47-1+rpt4": { "linux_commit": "655fc658a15ae7a6f37103754adb39ba52a9a14e", "upstream_version": "6.1.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.1.184", "compiled_filter": false }, "1:6.12.34-1+rpt1~bookworm": { "linux_commit": "8f77e03530f65209a377d25023e912b288e039cd", "upstream_version": "6.12.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.47-1+rpt1~bookworm": { "linux_commit": "359f37f0faefb712add32a39f98751aea67d5c1f", "upstream_version": "6.12.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.62-1+rpt1~bookworm": { "linux_commit": "a1073743767f9e7fdc7017ababd2a07ea0c97c1c", "upstream_version": "6.12.62", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.75-1+rpt1~bookworm": { "linux_commit": "89050b1059997d38d55462b323b099a6436dc10d", "upstream_version": "6.12.75", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.87-1+rpt1~bookworm": { "linux_commit": "ae4d75fb36deba0fe1a986d9bfae65755e082dd0", "upstream_version": "6.12.87", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.93-1+rpt1": { "linux_commit": "d8ab4e908235da7727f22dd36ad5af224671677d", "upstream_version": "6.12.93", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" } } } }, { "package": { "ecosystem": "Raspberry Pi OS:13", "name": "linux" }, "versions": [ "1:6.12.34-1+rpt1", "1:6.12.47-1+rpt1", "1:6.12.62-1+rpt1", "1:6.12.75-1+rpt1", "1:6.18.29-1+rpt1", "1:6.18.33-1+rpt1", "1:6.18.34-1+rpt1" ], "ecosystem_specific": { "binaries": [ { "binary_name": "linux-image-6.12.34+rpt-rpi-2712", "binary_version": "1:6.12.34-1+rpt1" }, { "binary_name": "linux-image-6.12.34+rpt-rpi-v8", "binary_version": "1:6.12.34-1+rpt1" }, { "binary_name": "linux-image-6.12.34+rpt-rpi-v8-rt", "binary_version": "1:6.12.34-1+rpt1" }, { "binary_name": "linux-image-6.12.47+rpt-rpi-2712", "binary_version": "1:6.12.47-1+rpt1" }, { "binary_name": "linux-image-6.12.47+rpt-rpi-v8", "binary_version": "1:6.12.47-1+rpt1" }, { "binary_name": "linux-image-6.12.47+rpt-rpi-v8-rt", "binary_version": "1:6.12.47-1+rpt1" }, { "binary_name": "linux-image-6.12.62+rpt-rpi-2712", "binary_version": "1:6.12.62-1+rpt1" }, { "binary_name": "linux-image-6.12.62+rpt-rpi-v8", "binary_version": "1:6.12.62-1+rpt1" }, { "binary_name": "linux-image-6.12.62+rpt-rpi-v8-rt", "binary_version": "1:6.12.62-1+rpt1" }, { "binary_name": "linux-image-6.12.75+rpt-rpi-2712", "binary_version": "1:6.12.75-1+rpt1" }, { "binary_name": "linux-image-6.12.75+rpt-rpi-v8", "binary_version": "1:6.12.75-1+rpt1" }, { "binary_name": "linux-image-6.12.75+rpt-rpi-v8-rt", "binary_version": "1:6.12.75-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-2712", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.29+rpt-rpi-v8-rt", "binary_version": "1:6.18.29-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-2712", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.33+rpt-rpi-v8-rt", "binary_version": "1:6.18.33-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-2712", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8", "binary_version": "1:6.18.34-1+rpt1" }, { "binary_name": "linux-image-6.18.34+rpt-rpi-v8-rt", "binary_version": "1:6.18.34-1+rpt1" } ] }, "database_specific": { "per_version": { "1:6.12.34-1+rpt1": { "linux_commit": "8f77e03530f65209a377d25023e912b288e039cd", "upstream_version": "6.12.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.47-1+rpt1": { "linux_commit": "359f37f0faefb712add32a39f98751aea67d5c1f", "upstream_version": "6.12.47", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.62-1+rpt1": { "linux_commit": "a1073743767f9e7fdc7017ababd2a07ea0c97c1c", "upstream_version": "6.12.62", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.12.75-1+rpt1": { "linux_commit": "89050b1059997d38d55462b323b099a6436dc10d", "upstream_version": "6.12.75", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.12.96" }, "1:6.18.29-1+rpt1": { "linux_commit": "66318c5b5cd8145a662303af12ed39ac07eb27cc", "upstream_version": "6.18.29", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.39" }, "1:6.18.33-1+rpt1": { "linux_commit": "95b85bebbedcaedfa7ca79116ed38b7376fba412", "upstream_version": "6.18.33", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.39" }, "1:6.18.34-1+rpt1": { "linux_commit": "c8c7494100e99ee05b11aaa4f0588a223a63d1af", "upstream_version": "6.18.34", "assessment": "commit ancestry (strak rule)", "upstream_fixed": "6.18.39" } } } } ], "references": [ { "type": "ADVISORY", "url": "https://www.cve.org/CVERecord?id=CVE-2026-64590" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/4a7c644e632741c2a3116a0d3da6c11de957a6ba" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/01126abc11bcc6a45b664293b0b5df715be911d7" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/dd7f1e572f44d3d039dc77e3989f537196c3bf52" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/0db56e7eae932f8e2f3eb44ad1a63633d8f504f8" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/d6552f5cff795d60e629f37513ecf23d88fd2f82" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/34696563461c9a23177feb6d8aff43f4c0510278" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/0449a6583c0ee76778d314e4e82f166fc97fa9d8" }, { "type": "FIX", "url": "https://git.kernel.org/stable/c/504e2b4ab97a51d56d966cd36d0997ad30b65b2d" } ], "database_specific": { "source": "https://git.kernel.org/pub/scm/linux/security/vulns.git", "upstream_modified": "2026-08-23T12:46:35Z" } }