{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38257", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:23.997Z", "datePublished": "2025-07-09T10:42:34.395Z", "dateUpdated": "2026-08-05T12:00:47.634Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:00:47.634Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\ns390/pkey: Prevent overflow in size calculation for memdup_user()\n\nNumber of apqn target list entries contained in 'nr_apqns' variable is\ndetermined by userspace via an ioctl call so the result of the product in\ncalculation of size passed to memdup_user() may overflow.\n\nIn this case the actual size of the allocated area and the value\ndescribing it won't be in sync leading to various types of unpredictable\nbehaviour later.\n\nUse a proper memdup_array_user() helper which returns an error if an\noverflow is detected. Note that it is different from when nr_apqns is\ninitially zero - that case is considered valid and should be handled in\nsubsequent pkey_handler implementations.\n\nFound by Linux Verification Center (linuxtesting.org)." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:L/A:H", "baseScore": 7.3, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable code is reached only through ioctl calls on the /dev/pkey misc device node; there is no network, adjacent-network, or remote-peer data path into `_copy_apqns_from_user()`. The in-kernel API (`pkey_key2protkey`) and sysfs paths always pass a NULL apqn list with count 0.\nAC:L - `apqn_entries` is a plain u32 field copied directly from the ioctl argument struct, so the attacker sets the value outright in a single deterministic ioctl call. No race, no memory-layout dependency, and no condition outside the attacker's control.\nPR:L - The pkey miscdevice is registered with `.mode = 0666`, making it world read/write, and neither `pkey_unlocked_ioctl()` nor any of the four reachable sub-handlers performs a `capable()` or `CAP_*` check. Any local unprivileged user on an s390 system with CONFIG_PKEY enabled (standard in distro mainframe kernels) can trigger it.\nUI:N - The attacker issues the ioctl directly from their own process; no victim action, mount, or file open by another user is involved.\nS:U - The undersized allocation and the resulting out-of-bounds access are both in kernel heap memory within the same security authority. No VM, IOMMU, or sandbox boundary is crossed.\nC:H - The size/count desynchronization causes the CCA handlers to walk `apqns[i]` far past the end of an attacker-sized kmalloc buffer, an unbounded slab out-of-bounds read rather than a few-byte overread. The disclosed heap contents are consumed as card/domain selectors, exposing adjacent kernel object data.\nI:L - All handler signatures take `const struct pkey_apqn *apqns`, so the desynchronized buffer is only ever read — there is no out-of-bounds write or control-flow hijack primitive. Integrity impact is limited to out-of-bounds heap values steering crypto-adapter requests to attacker-uncontrolled card/domain pairs.\nA:H - Iterating up to billions of entries past a small kmalloc'd buffer reliably reaches unmapped memory, producing a kernel oops/panic, and the loop contains no `cond_resched()` so it can also stall the CPU. Any unprivileged local user can repeat this at will." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "drivers/s390/crypto/pkey_api.c" ], "versions": [ { "version": "f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d", "lessThan": "ad1bdd24a02d5a8d119af8e4cd50933780a6d29f", "status": "affected", "versionType": "git" }, { "version": "f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d", "lessThan": "faa1ab4a23c42e34dc000ef4977b751d94d5148c", "status": "affected", "versionType": "git" }, { "version": "f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d", "lessThan": "88f3869649edbc4a13f6c2877091f81cd5a50f05", "status": "affected", "versionType": "git" }, { "version": "f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d", "lessThan": "f855b119e62b004a5044ed565f2a2b368c4d3f16", "status": "affected", "versionType": "git" }, { "version": "f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d", "lessThan": "73483ca7e07a5e39bdf612eec9d3d293e8bef649", "status": "affected", "versionType": "git" }, { "version": "f2bbc96e7cfad3891b7bf9bd3e566b9b7ab4553d", "lessThan": "7360ee47599af91a1d5f4e74d635d9408a54e489", "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/s390/crypto/pkey_api.c" ], "versions": [ { "version": "5.4", "status": "affected" }, { "version": "0", "lessThan": "5.4", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.187", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.143", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.96", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.36", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.5", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16", "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": "5.4", "versionEndExcluding": "5.15.187" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.1.143" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.6.96" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.12.36" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.15.5" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.4", "versionEndExcluding": "6.16" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/ad1bdd24a02d5a8d119af8e4cd50933780a6d29f" }, { "url": "https://git.kernel.org/stable/c/faa1ab4a23c42e34dc000ef4977b751d94d5148c" }, { "url": "https://git.kernel.org/stable/c/88f3869649edbc4a13f6c2877091f81cd5a50f05" }, { "url": "https://git.kernel.org/stable/c/f855b119e62b004a5044ed565f2a2b368c4d3f16" }, { "url": "https://git.kernel.org/stable/c/73483ca7e07a5e39bdf612eec9d3d293e8bef649" }, { "url": "https://git.kernel.org/stable/c/7360ee47599af91a1d5f4e74d635d9408a54e489" } ], "title": "s390/pkey: Prevent overflow in size calculation for memdup_user()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:35:59.898Z" } } ] } }