{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-63929",
        "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "state": "PUBLISHED",
        "assignerShortName": "Linux",
        "dateReserved": "2026-07-19T07:54:57.021Z",
        "datePublished": "2026-07-19T14:55:29.309Z",
        "dateUpdated": "2026-07-19T14:55:29.309Z"
    },
    "containers": {
        "cna": {
            "providerMetadata": {
                "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
                "shortName": "Linux",
                "dateUpdated": "2026-07-19T14:55:29.309Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: buffer: Fix DMA fence leak in iio_buffer_enqueue_dmabuf()\n\niio_buffer_enqueue_dmabuf() allocates a struct iio_dma_fence (104 bytes,\nkmalloc-128) via kmalloc_obj()+dma_fence_init(), which sets the initial\nkref to 1.  It then calls dma_resv_add_fence() which takes a second\nreference (kref=2), and stores a raw pointer in block->fence.\n\nOn the success path the function returns without calling dma_fence_put()\nto release the initial reference, so every buffer enqueue permanently\nleaks one kmalloc-128 allocation.\n\nThe iio_buffer_cleanup() work item only releases the temporary reference\ntaken during completion signalling by iio_buffer_signal_dmabuf_done();\nthe initial reference from dma_fence_init() is never released.\n\nWith four iio_rwdev instances at 240kHz and 512 samples per buffer,\nthis produces ~1875 kmalloc-128 allocations per second matching the\nobserved slab growth exactly. A test with ftrace confirmed that the\ndma_fence_destroy event was never triggered.\n\nFix by calling dma_fence_put() after dma_resv_add_fence(), transferring\nownership of the fence to the DMA reservation object. The DMA fence then\ngets properly discarded after being signalled."
                }
            ],
            "affected": [
                {
                    "product": "Linux",
                    "vendor": "Linux",
                    "defaultStatus": "unaffected",
                    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
                    "programFiles": [
                        "drivers/iio/industrialio-buffer.c"
                    ],
                    "versions": [
                        {
                            "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
                            "lessThan": "9678aeed8b77d495a417dd057d479f3733094019",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
                            "lessThan": "3412a95afaa5d3262008dfc34f3c7be33d8151dc",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
                            "lessThan": "96cdeaba6a008503455b78a9641c05c2a886a7ec",
                            "status": "affected",
                            "versionType": "git"
                        },
                        {
                            "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f",
                            "lessThan": "a093999355084bdbfe6e97f1dd232e58a1525f0b",
                            "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/iio/industrialio-buffer.c"
                    ],
                    "versions": [
                        {
                            "version": "6.11",
                            "status": "affected"
                        },
                        {
                            "version": "0",
                            "lessThan": "6.11",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.12.93",
                            "lessThanOrEqual": "6.12.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "6.18.35",
                            "lessThanOrEqual": "6.18.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.0.12",
                            "lessThanOrEqual": "7.0.*",
                            "status": "unaffected",
                            "versionType": "semver"
                        },
                        {
                            "version": "7.1",
                            "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": "6.11",
                                    "versionEndExcluding": "6.12.93"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.11",
                                    "versionEndExcluding": "6.18.35"
                                },
                                {
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                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.11",
                                    "versionEndExcluding": "7.0.12"
                                },
                                {
                                    "vulnerable": true,
                                    "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
                                    "versionStartIncluding": "6.11",
                                    "versionEndExcluding": "7.1"
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            ],
            "references": [
                {
                    "url": "https://git.kernel.org/stable/c/9678aeed8b77d495a417dd057d479f3733094019"
                },
                {
                    "url": "https://git.kernel.org/stable/c/3412a95afaa5d3262008dfc34f3c7be33d8151dc"
                },
                {
                    "url": "https://git.kernel.org/stable/c/96cdeaba6a008503455b78a9641c05c2a886a7ec"
                },
                {
                    "url": "https://git.kernel.org/stable/c/a093999355084bdbfe6e97f1dd232e58a1525f0b"
                }
            ],
            "title": "iio: buffer: Fix DMA fence leak in iio_buffer_enqueue_dmabuf()",
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}