{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-89941", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-11T19:38:34.777Z", "datePublished": "2026-09-16T10:32:29.148Z", "dateUpdated": "2026-10-19T08:55:15.605Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T08:55:15.605Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\niio: buffer: Make IIO DMA fence release RCU-safe\n\nThe `dma_fence` documentation states that if a custom release\nimplementation is provided, the `dma_fence` object must be freed in an\nRCU-safe way. The current `iio_dma_fence` implementation uses `kfree()`,\nwhich might result in a use-after-free.\n\nRemove the custom `release` implementation. This makes the DMA fence core\nfall back to `dma_fence_free()`, which calls `kfree_rcu()` on the fence.\nThis requires that the fence be the first member of `struct iio_dma_fence`.\n\nUsing the default release method for extended DMA fence structures is a\ncommon pattern." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The use-after-free is reached only through local IIO character-device ioctls (IIO_BUFFER_GET_FD_IOCTL then IIO_BUFFER_DMABUF_ATTACH/ENQUEUE_IOCTL on /dev/iio:deviceN); there is no network, Bluetooth, or USB packet path into the IIO DMA fence release.\nAC:L - The attacker controls both sides of the race by enqueueing IIO DMA-BUF transfers that create and later kfree() the fence while concurrently waiting on or exporting the same dma-buf's reservation fences via DMA_BUF_IOCTL_SYNC/EXPORT_SYNC_FILE, so the missing RCU grace period is attacker-driven.\nPR:L - The IIO open and ioctl path performs no capability check; only filesystem access to /dev/iio:deviceN is required. On Android, automotive, and industrial/SDR systems that ship DMA-capable IIO converters, that node is commonly group-accessible to unprivileged sensor or application users.\nUI:N - The attacker opens the IIO device, attaches their own DMA-BUF, and issues enqueue and dma-buf sync/export ioctls themselves; no separate victim action is required.\nS:U - The freed iio_dma_fence lives in the host kernel heap and any resulting corruption stays within the same kernel security authority; this is not a VM escape or IOMMU/DMA boundary bypass.\nC:H - Immediate kfree() of the dma_fence lets concurrent dma_resv RCU walkers (dma_fence_get_rcu, dma_fence_driver_name) read the reclaimed slab object; per kernel scoring guidance a use-after-free is High confidentiality impact.\nI:H - The freed dma_fence contains ops function pointers, callback lists, and a spinlock used after free; reclaiming the object with attacker-controlled data yields write and control-flow hijack primitives, so integrity impact is High.\nA:H - Use-after-free of the fence from dma_fence_release or dma_resv iteration causes a kernel oops or panic even without a full exploit, so availability impact is High." } ] } ], "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": "311595dc0b5621f74d8eb4dc38ef4efcdfe7e769", "status": "affected", "versionType": "git" }, { "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f", "lessThan": "06a9460b8b792e109cbc934a856d02e5cff217ef", "status": "affected", "versionType": "git" }, { "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f", "lessThan": "11cef99491117d4264603df159c4ff5f3845a059", "status": "affected", "versionType": "git" }, { "version": "3e26d9f08fbe0b73e951a5e810fdb7a332b7e37f", "lessThan": "8662e56c31cf23b61ca3d11b516efb94c35b8026", "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": "6.12.110", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.51", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.5", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "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": "6.12.110" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "6.18.51" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.2.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "6.11", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/311595dc0b5621f74d8eb4dc38ef4efcdfe7e769" }, { "url": "https://git.kernel.org/stable/c/06a9460b8b792e109cbc934a856d02e5cff217ef" }, { "url": "https://git.kernel.org/stable/c/11cef99491117d4264603df159c4ff5f3845a059" }, { "url": "https://git.kernel.org/stable/c/8662e56c31cf23b61ca3d11b516efb94c35b8026" } ], "title": "iio: buffer: Make IIO DMA fence release RCU-safe", "x_generator": { "engine": "bippy-1.2.0" } } } }