CVE-2023-54042 (GCVE-0-2023-54042)
Vulnerability from cvelistv5 – Published: 2025-12-24 10:56 – Updated: 2026-08-05 09:16
VLAI
EPSS
VEX
Title
powerpc/64s: Fix VAS mm use after free
Summary
In the Linux kernel, the following vulnerability has been resolved:
powerpc/64s: Fix VAS mm use after free
The refcount on mm is dropped before the coprocessor is detached.
Severity
7.8 (High)
Assigner
References
Impacted products
2 products
| Vendor | Product | Version | CPE status | |
|---|---|---|---|---|
| Linux | Linux |
Affected:
7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85 , < f7d92313002b2d543500cc417d8079aaed1fb0a8
(git)
Affected: 7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85 , < 4e82f92c349ea603736ade1e814861c0182a55ad (git) Affected: 7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85 , < db8657fdd53c5e3069149d7f957cb60e63027bb2 (git) Affected: 7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85 , < 421cd1544480f2458042fe7f4913a2069c4d7251 (git) Affected: 7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85 , < b4bda59b47879cce38a6ec5a01cd3cac702b5331 (git) |
guessed | |
| Linux | Linux |
Affected:
5.14
Unaffected: 0 , < 5.14 (semver) Unaffected: 5.15.121 , ≤ 5.15.* (semver) Unaffected: 6.1.39 , ≤ 6.1.* (semver) Unaffected: 6.3.13 , ≤ 6.3.* (semver) Unaffected: 6.4.4 , ≤ 6.4.* (semver) Unaffected: 6.5 , ≤ * (original_commit_for_fix) |
guessed |
{
"containers": {
"cna": {
"affected": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/powerpc/platforms/powernv/vas-window.c",
"arch/powerpc/platforms/pseries/vas.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
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"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
"lessThan": "4e82f92c349ea603736ade1e814861c0182a55ad",
"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
"lessThan": "db8657fdd53c5e3069149d7f957cb60e63027bb2",
"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
"lessThan": "421cd1544480f2458042fe7f4913a2069c4d7251",
"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
"lessThan": "b4bda59b47879cce38a6ec5a01cd3cac702b5331",
"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"arch/powerpc/platforms/powernv/vas-window.c",
"arch/powerpc/platforms/pseries/vas.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.14"
},
{
"lessThan": "5.14",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.121",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.3.*",
"status": "unaffected",
"version": "6.3.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.4.*",
"status": "unaffected",
"version": "6.4.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix"
}
]
}
],
"cpeApplicability": [
{
"nodes": [
{
"cpeMatch": [
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "5.15.121",
"versionStartIncluding": "5.14",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.1.39",
"versionStartIncluding": "5.14",
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},
{
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"versionStartIncluding": "5.14",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.4.4",
"versionStartIncluding": "5.14",
"vulnerable": true
},
{
"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*",
"versionEndExcluding": "6.5",
"versionStartIncluding": "5.14",
"vulnerable": true
}
],
"negate": false,
"operator": "OR"
}
]
}
],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s: Fix VAS mm use after free\n\nThe refcount on mm is dropped before the coprocessor is detached."
}
],
"metrics": [
{
"cvssV3_1": {
"baseScore": 7.8,
"baseSeverity": "HIGH",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"scenarios": [
{
"lang": "en",
"value": "AV:L - The vulnerability is reached through a local character device (`/dev/crypto/nx-gzip`) via `open()` + `ioctl(VAS_TX_WIN_OPEN)` + process exit/`close()`. No network or adjacent-network path exists to the VAS window close path.\nAC:L - The attacker fully controls the trigger: open a window and exit the process, at which point the VAS reference is deterministically the last `mm_count` reference, so `mmdrop()` frees the mm and the immediately following `mm_context_remove_vas_window()` dereferences it. No unwinnable race or uncontrollable precondition is involved, and the sequence can be repeated freely to groom `mm_cachep` reallocation.\nPR:L - Only an unprivileged local account is needed \u2014 there is no `capable()` or `CAP_*` check on any path from the ioctl to `vas_deallocate_window()`/`vas_win_close()`, and `Documentation/powerpc/vas-api.rst` states no special privileges are required to open the nx-gzip device, which is deliberately exposed to ordinary user-space compression libraries.\nUI:N - The attacking process performs every step itself (open, ioctl, exit); no action by another user or administrator is required.\nS:U - The corruption is confined to kernel memory managed by the same kernel security authority; no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - The freed `mm_struct` is read after free \u2014 `context.id`, `context.copros`, `context.active_cpus`, `mm_users`, and `mm_cpumask()` \u2014 and `mm_cachep` objects are readily reallocated by forking, so the attacker can influence the contents read; a UAF of this kind is leverageable for kernel memory disclosure, and the corrupted TLB-flush scoping can leave stale translations exposing another process\u0027s memory.\nI:H - Multiple writes land in the freed object: `atomic_dec_if_positive()` on `context.copros`/`context.vas_windows`, plus cross-CPU `atomic_dec(\u0026mm-\u003econtext.active_cpus)`, `cpumask_clear_cpu()`, and a possible extra `mmdrop_lazy_tlb()` refcount underflow, giving write primitives into a reallocated live `mm_struct` (or SLUB freelist metadata) that are exploitable for further corruption.\nA:H - The use-after-free reliably corrupts freed slab memory and issues hardware TLB invalidations with a stale PID plus IPIs derived from a freed cpumask, producing oopses, `WARN_ON()` splats (fatal with `panic_on_warn`), slab corruption, and kernel panics \u2014 triggerable repeatedly by any local user."
}
]
}
],
"providerMetadata": {
"dateUpdated": "2026-08-05T09:16:42.390Z",
"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"shortName": "Linux"
},
"references": [
{
"url": "https://git.kernel.org/stable/c/f7d92313002b2d543500cc417d8079aaed1fb0a8"
},
{
"url": "https://git.kernel.org/stable/c/4e82f92c349ea603736ade1e814861c0182a55ad"
},
{
"url": "https://git.kernel.org/stable/c/db8657fdd53c5e3069149d7f957cb60e63027bb2"
},
{
"url": "https://git.kernel.org/stable/c/421cd1544480f2458042fe7f4913a2069c4d7251"
},
{
"url": "https://git.kernel.org/stable/c/b4bda59b47879cce38a6ec5a01cd3cac702b5331"
}
],
"title": "powerpc/64s: Fix VAS mm use after free",
"x_generator": {
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}
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"cveMetadata": {
"assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"assignerShortName": "Linux",
"cveId": "CVE-2023-54042",
"datePublished": "2025-12-24T10:56:07.565Z",
"dateReserved": "2025-12-24T10:53:46.181Z",
"dateUpdated": "2026-08-05T09:16:42.390Z",
"state": "PUBLISHED"
},
"dataType": "CVE_RECORD",
"dataVersion": "5.2",
"vulnerability-lookup:meta": {
"epss": {
"cve": "CVE-2023-54042",
"date": "2026-09-17",
"epss": "0.00136",
"percentile": "0.03387"
},
"nvd": {
"cve": {
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"arch/powerpc/platforms/powernv/vas-window.c",
"arch/powerpc/platforms/pseries/vas.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "f7d92313002b2d543500cc417d8079aaed1fb0a8",
"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
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"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
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"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
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"status": "affected",
"version": "7bc6f71bdff5f8921e324da0a8fad6f4e2e63a85",
"versionType": "git"
},
{
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"versionType": "git"
}
]
},
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"product": "Linux",
"programFiles": [
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"arch/powerpc/platforms/pseries/vas.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "5.14"
},
{
"lessThan": "5.14",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "5.15.*",
"status": "unaffected",
"version": "5.15.121",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.1.*",
"status": "unaffected",
"version": "6.1.39",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.3.*",
"status": "unaffected",
"version": "6.3.13",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.4.*",
"status": "unaffected",
"version": "6.4.4",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "6.5",
"versionType": "original_commit_for_fix"
}
]
}
],
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
}
],
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\npowerpc/64s: Fix VAS mm use after free\n\nThe refcount on mm is dropped before the coprocessor is detached."
}
],
"id": "CVE-2023-54042",
"lastModified": "2026-08-04T10:19:26.100",
"metrics": {
"cvssMetricV31": [
{
"cvssData": {
"attackComplexity": "LOW",
"attackVector": "LOCAL",
"availabilityImpact": "HIGH",
"baseScore": 7.8,
"baseSeverity": "HIGH",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"privilegesRequired": "LOW",
"scope": "UNCHANGED",
"userInteraction": "NONE",
"vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
"version": "3.1"
},
"exploitabilityScore": 1.8,
"impactScore": 5.9,
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary"
}
]
},
"published": "2025-12-24T11:15:57.187",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/421cd1544480f2458042fe7f4913a2069c4d7251"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4e82f92c349ea603736ade1e814861c0182a55ad"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b4bda59b47879cce38a6ec5a01cd3cac702b5331"
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"url": "https://git.kernel.org/stable/c/db8657fdd53c5e3069149d7f957cb60e63027bb2"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/f7d92313002b2d543500cc417d8079aaed1fb0a8"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Deferred"
}
},
"redhat_vex": {
"aggregate_severity": "Low",
"current_release_date": "2026-08-21T02:37:21+00:00",
"cve": "CVE-2023-54042",
"id": "CVE-2023-54042",
"initial_release_date": "2023-01-01T00:00:00+00:00",
"product_status:known_affected": "156",
"product_status:known_not_affected": "118",
"source": "Red Hat CSAF VEX",
"status": "final",
"title": "kernel: powerpc/64s: Fix VAS mm use after free",
"url": "https://security.access.redhat.com/data/csaf/v2/vex/2023/cve-2023-54042.json",
"version": "3"
}
}
}
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Experimental. This forecast is provided for visualization only and may change without notice. Do not use it for operational decisions.
Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.
Sightings
| Author | Source | Type | Date | Other |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.
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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the
vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base
model, served locally by ML-Gateway.
They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.
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Related by attack behaviour
Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.
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