{ "schemaVersion": 1, "attribution": [ { "source": "CISA Known Exploited Vulnerabilities", "url": "https://www.cisa.gov/known-exploited-vulnerabilities-catalog", "licence": "US government work" }, { "source": "GitHub Advisory Database", "url": "https://github.com/advisories", "licence": "CC BY 4.0" }, { "source": "Have I Been Pwned", "url": "https://haveibeenpwned.com/", "licence": "CC BY 4.0" }, { "source": "CVE Program (CVE records)", "url": "https://www.cve.org/Legal/TermsOfUse", "licence": "CVE Terms of Use", "notice": "Copyright © 1999-2026, The MITRE Corporation. CVE is a trademark and the CVE logo is a registered trademark of The MITRE Corporation.", "terms": "CVE Usage: MITRE hereby grants you a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare derivative works of, publicly display, publicly perform, sublicense, and distribute Common Vulnerabilities and Exposures (CVE™). Any copy you make for such purposes is authorized provided that you reproduce MITRE's copyright designation and this license in any such copy." }, { "source": "FIRST EPSS", "url": "https://www.first.org/epss/", "licence": "free to use; FIRST requests attribution" } ], "record": { "id": "CVE-2026-64590", "sourceURL": "https://www.cve.org/CVERecord?id=CVE-2026-64590", "idYear": 2026, "status": "PUBLISHED", "publishedAt": "2026-08-06T07:13:47.888Z", "updatedAt": "2026-08-23T12:45:45.786Z", "importedAt": "2026-10-24T01:58:25.636Z", "snapshot": { "id": "cve_2026-10-24_midnight_baseline", "at": "2026-10-24T00:00:00.000Z", "source": "https://github.com/CVEProject/cvelistV5/releases/tag/cve_2026-10-24_0100Z" }, "facts": { "title": "dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning", "summary": "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": [ { "vendor": "Linux", "product": "Linux", "defaultStatus": "unaffected", "versions": [ { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "4a7c644e632741c2a3116a0d3da6c11de957a6ba" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "01126abc11bcc6a45b664293b0b5df715be911d7" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "dd7f1e572f44d3d039dc77e3989f537196c3bf52" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "0db56e7eae932f8e2f3eb44ad1a63633d8f504f8" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "d6552f5cff795d60e629f37513ecf23d88fd2f82" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "34696563461c9a23177feb6d8aff43f4c0510278" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "0449a6583c0ee76778d314e4e82f166fc97fa9d8" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "status": "affected", "versionType": "git", "lessThan": "504e2b4ab97a51d56d966cd36d0997ad30b65b2d" } ] }, { "vendor": "Linux", "product": "Linux", "defaultStatus": "affected", "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "status": "unaffected", "versionType": "semver", "lessThan": "5.6" }, { "version": "5.10.266", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.10.*" }, { "version": "5.15.217", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "5.15.*" }, { "version": "6.1.184", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.1.*" }, { "version": "6.6.148", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.6.*" }, { "version": "6.12.96", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.12.*" }, { "version": "6.18.39", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "6.18.*" }, { "version": "7.1.4", "status": "unaffected", "versionType": "semver", "lessThanOrEqual": "7.1.*" }, { "version": "7.2", "status": "unaffected", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*" } ] } ] } } }