{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-64590", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-07-19T15:36:31.798Z", "datePublished": "2026-08-06T07:13:47.888Z", "dateUpdated": "2026-08-23T12:45:45.786Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-23T12:45:45.786Z" }, "descriptions": [ { "lang": "en", "value": "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": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/dma-buf/udmabuf.c" ], "versions": [ { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "4a7c644e632741c2a3116a0d3da6c11de957a6ba", "status": "affected", "versionType": "git" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "01126abc11bcc6a45b664293b0b5df715be911d7", "status": "affected", "versionType": "git" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "dd7f1e572f44d3d039dc77e3989f537196c3bf52", "status": "affected", "versionType": "git" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "0db56e7eae932f8e2f3eb44ad1a63633d8f504f8", "status": "affected", "versionType": "git" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "d6552f5cff795d60e629f37513ecf23d88fd2f82", "status": "affected", "versionType": "git" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "34696563461c9a23177feb6d8aff43f4c0510278", "status": "affected", "versionType": "git" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "0449a6583c0ee76778d314e4e82f166fc97fa9d8", "status": "affected", "versionType": "git" }, { "version": "284562e1f34874e267d4f499362c3816f8f6bc3f", "lessThan": "504e2b4ab97a51d56d966cd36d0997ad30b65b2d", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/dma-buf/udmabuf.c" ], "versions": [ { "version": "5.6", "status": "affected" }, { "version": "0", "lessThan": "5.6", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.266", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.217", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.148", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.96", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.39", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.1.4", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.10.266" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "5.15.217" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.1.184" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.6.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.12.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "6.18.39" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.1.4" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.6", "versionEndExcluding": "7.2" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/4a7c644e632741c2a3116a0d3da6c11de957a6ba" }, { "url": "https://git.kernel.org/stable/c/01126abc11bcc6a45b664293b0b5df715be911d7" }, { "url": "https://git.kernel.org/stable/c/dd7f1e572f44d3d039dc77e3989f537196c3bf52" }, { "url": "https://git.kernel.org/stable/c/0db56e7eae932f8e2f3eb44ad1a63633d8f504f8" }, { "url": "https://git.kernel.org/stable/c/d6552f5cff795d60e629f37513ecf23d88fd2f82" }, { "url": "https://git.kernel.org/stable/c/34696563461c9a23177feb6d8aff43f4c0510278" }, { "url": "https://git.kernel.org/stable/c/0449a6583c0ee76778d314e4e82f166fc97fa9d8" }, { "url": "https://git.kernel.org/stable/c/504e2b4ab97a51d56d966cd36d0997ad30b65b2d" } ], "title": "dma-buf/udmabuf: skip redundant cpu sync to fix cacheline EEXIST warning", "x_generator": { "engine": "bippy-1.2.0" } } } }