{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-21734", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2024-12-29T08:45:45.756Z", "datePublished": "2025-02-27T02:12:11.663Z", "dateUpdated": "2026-08-05T11:54:03.438Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T11:54:03.438Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nmisc: fastrpc: Fix copy buffer page size\n\nFor non-registered buffer, fastrpc driver copies the buffer and\npass it to the remote subsystem. There is a problem with current\nimplementation of page size calculation which is not considering\nthe offset in the calculation. This might lead to passing of\nimproper and out-of-bounds page size which could result in\nmemory issue. Calculate page start and page end using the offset\nadjusted address instead of absolute address." } ], "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 vulnerable code is reached only through the FASTRPC_IOCTL_INVOKE ioctl on the /dev/fastrpc-* character device, requiring local access to the system. There is no network-facing path into fastrpc_get_args().\nAC:L - The attacker fully and deterministically controls every input that produces the miscalculation — the overlap offset (via user-supplied overlapping args[i].ptr/length ranges), the in-page alignment of `args` (via nscalars-derived metalen and preceding buffer lengths), and the buffer length — so the wrong page count can be produced reliably on the first attempt with no race or unpredictable state.\nPR:L - No capability check exists anywhere on the ioctl path; an unprivileged process only needs to open the fastrpc device node, and the driver explicitly registers a non-secure node for untrusted applications to offload to unsigned PDs (`is_session_rejected()`), which is exactly how untrusted Android apps use CDSP.\nUI:N - The attacker performs the entire sequence (open, init, invoke) itself from its own process; no victim action of any kind is needed.\nS:U - The vulnerable component and the impacted memory are both the host Linux kernel, so the exploit stays within a single security authority — this is standard local kernel memory corruption/privilege escalation rather than a VM or hypervisor boundary escape.\nC:H - An over-computed pages[i].size hands the DSP a physical page descriptor covering kernel memory beyond the coherent copy buffer, and on the unsigned-PD path the attacker controls the DSP-side code that reads that mapping and returns the contents, yielding disclosure of adjacent kernel memory.\nI:H - The same out-of-bounds page grant is read/write from the coprocessor's side, so attacker-controlled DSP code can write into kernel memory adjacent to the DMA-coherent allocation, giving a corruption primitive usable for privilege escalation.\nA:H - The mismatched page list either lets the DSP corrupt kernel memory outside the buffer or, in the under-sized direction, causes SMMU context faults and DSP subsystem crashes/restarts, and the ioctl can be repeated at will by any process holding the device fd." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/misc/fastrpc.c" ], "versions": [ { "version": "02b45b47fbe84e23699bb6bdc74d4c2780e282b4", "lessThan": "c56ba3ea8e3c9a69a992aad18f7a65e43e51d623", "status": "affected", "versionType": "git" }, { "version": "02b45b47fbe84e23699bb6bdc74d4c2780e282b4", "lessThan": "c0464bad0e85fcd5d47e4297d1e410097c979e55", "status": "affected", "versionType": "git" }, { "version": "02b45b47fbe84e23699bb6bdc74d4c2780e282b4", "lessThan": "24a79c6bc8de763f7c50f4f84f8b0c183bc25a51", "status": "affected", "versionType": "git" }, { "version": "02b45b47fbe84e23699bb6bdc74d4c2780e282b4", "lessThan": "c3f7161123fcbdc64e90119ccce292d8b66281c4", "status": "affected", "versionType": "git" }, { "version": "02b45b47fbe84e23699bb6bdc74d4c2780e282b4", "lessThan": "e966eae72762ecfdbdb82627e2cda48845b9dd66", "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/misc/fastrpc.c" ], "versions": [ { "version": "5.2", "status": "affected" }, { "version": "0", "lessThan": "5.2", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.129", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.78", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.14", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.13.3", "lessThanOrEqual": "6.13.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.14", "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": "5.2", "versionEndExcluding": "6.1.129" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.6.78" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.12.14" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.13.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.2", "versionEndExcluding": "6.14" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/c56ba3ea8e3c9a69a992aad18f7a65e43e51d623" }, { "url": "https://git.kernel.org/stable/c/c0464bad0e85fcd5d47e4297d1e410097c979e55" }, { "url": "https://git.kernel.org/stable/c/24a79c6bc8de763f7c50f4f84f8b0c183bc25a51" }, { "url": "https://git.kernel.org/stable/c/c3f7161123fcbdc64e90119ccce292d8b66281c4" }, { "url": "https://git.kernel.org/stable/c/e966eae72762ecfdbdb82627e2cda48845b9dd66" } ], "title": "misc: fastrpc: Fix copy buffer page size", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/03/msg00028.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T19:36:37.586Z" } } ] } }