{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38584", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.026Z", "datePublished": "2025-08-19T17:03:06.172Z", "dateUpdated": "2026-08-05T12:03:10.424Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:03:10.424Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npadata: Fix pd UAF once and for all\n\nThere is a race condition/UAF in padata_reorder that goes back\nto the initial commit. A reference count is taken at the start\nof the process in padata_do_parallel, and released at the end in\npadata_serial_worker.\n\nThis reference count is (and only is) required for padata_replace\nto function correctly. If padata_replace is never called then\nthere is no issue.\n\nIn the function padata_reorder which serves as the core of padata,\nas soon as padata is added to queue->serial.list, and the associated\nspin lock released, that padata may be processed and the reference\ncount on pd would go away.\n\nFix this by getting the next padata before the squeue->serial lock\nis released.\n\nIn order to make this possible, simplify padata_reorder by only\ncalling it once the next padata arrives." } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The vulnerable padata reorder path is only driven by pcrypt AEAD requests, which an unprivileged local user submits via AF_ALG sockets (or in-kernel IPsec); the required `padata_replace()`/`padata_free_shell()` side is a local sysfs/CPU-hotplug/netlink action, so a purely remote attacker cannot set up the necessary state.\nAC:H - The attacker controls only one side of the race (the pcrypt request stream); dropping the base `pd` reference requires `padata_replace()` via root-only sysfs cpumask writes, CPU hotplug, or init-ns CAP_NET_ADMIN `crypto_del_alg` — conditions truly outside an unprivileged attacker's control, and the window between `spin_unlock(&squeue->serial.lock)` and the next `pd` dereference must coincide with the final refcount drop.\nPR:L - An unprivileged user with no capabilities can open AF_ALG sockets and flood `pcrypt(...)` requests to drive `padata_do_parallel`/`padata_do_serial` and hold the race open; no capability check exists on that path.\nUI:N - No victim action is needed — the `padata_replace()` trigger routinely occurs automatically via CPU hotplug (cloud vCPU resize, thermal/power hotplug on embedded and Android, suspend/resume offlining secondary CPUs) rather than through a human interacting with content.\nS:U - The use-after-free is on a kernel slab/percpu object and its consequences stay within the kernel's own security authority; no VM, IOMMU, or sandbox boundary is crossed.\nC:H - The freed `struct parallel_data` and its freed percpu `reorder_list`/`squeue` are read after free (`pd->cpu`, `pd->processed`, `reorder->lock`, list pointers), and reclaiming those allocations with attacker-sprayed objects turns the UAF into an arbitrary kernel-memory read primitive.\nI:H - After the free, `padata_reorder()` writes into the freed object (`spin_unlock_bh(&pd->lock)`, `refcount_inc()`, `list_del_init()`) and queues `&pd->reorder_work` and `&squeue->work` — work_structs inside freed memory whose `func` pointer is later invoked, giving control-flow hijack and privilege escalation once the slab is reclaimed.\nA:H - Even unexploited, the use-after-free corrupts freed slab and percpu memory, takes a spinlock in freed storage, and queues a work item with a stale function pointer, reliably producing a kernel oops/panic." } ] } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/padata.h", "kernel/padata.c" ], "versions": [ { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "a2048e475e22b13dc3e53d485b7e6e11464ed9a6", "status": "affected", "versionType": "git" }, { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "73f132e60857038416540c3599b1de6033d7575a", "status": "affected", "versionType": "git" }, { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "609e59193fc6d9dd323f1c6ae1fdd721f1c79680", "status": "affected", "versionType": "git" }, { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "a11a12a9880ab37342b73c93cfe1a3ada02ff0db", "status": "affected", "versionType": "git" }, { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "f231d5d001ec75f5886c02d496a4c79edc383d45", "status": "affected", "versionType": "git" }, { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "dbe3e911a59bda6de96e7cae387ff882c2c177fa", "status": "affected", "versionType": "git" }, { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "cdf79bd2e1ecb3cc75631c73d8f4149be6019a52", "status": "affected", "versionType": "git" }, { "version": "16295bec6398a3eedc9377e1af6ff4c71b98c300", "lessThan": "71203f68c7749609d7fc8ae6ad054bdedeb24f91", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/padata.h", "kernel/padata.c" ], "versions": [ { "version": "2.6.34", "status": "affected" }, { "version": "0", "lessThan": "2.6.34", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.258", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.209", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.175", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.140", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.86", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.10", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.1", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17", "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": "2.6.34", "versionEndExcluding": "5.10.258" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "5.15.209" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.1.175" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.6.140" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.12.86" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.15.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.16.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "2.6.34", "versionEndExcluding": "6.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/a2048e475e22b13dc3e53d485b7e6e11464ed9a6" }, { "url": "https://git.kernel.org/stable/c/73f132e60857038416540c3599b1de6033d7575a" }, { "url": "https://git.kernel.org/stable/c/609e59193fc6d9dd323f1c6ae1fdd721f1c79680" }, { "url": "https://git.kernel.org/stable/c/a11a12a9880ab37342b73c93cfe1a3ada02ff0db" }, { "url": "https://git.kernel.org/stable/c/f231d5d001ec75f5886c02d496a4c79edc383d45" }, { "url": "https://git.kernel.org/stable/c/dbe3e911a59bda6de96e7cae387ff882c2c177fa" }, { "url": "https://git.kernel.org/stable/c/cdf79bd2e1ecb3cc75631c73d8f4149be6019a52" }, { "url": "https://git.kernel.org/stable/c/71203f68c7749609d7fc8ae6ad054bdedeb24f91" } ], "title": "padata: Fix pd UAF once and for all", "x_generator": { "engine": "bippy-1.2.0" } } } }