FKIE_CVE-2026-68458
Vulnerability from fkie_nvd - Published: 2026-08-15 06:18 - Updated: 2026-08-17 06:17
Severity
Summary
In the Linux kernel, the following vulnerability has been resolved:
binder: cache secctx size before release zeroes it
binder_transaction() bounds the scatter-gather buffer area with
sg_buf_end_offset and subtracts the aligned LSM context size because
the secctx is written at the tail of that area. The subtraction reads
lsmctx.len, but that field has already been cleared by the time the
line runs:
security_secid_to_secctx(secid, &lsmctx) /* lsmctx.len set */
lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64))
extra_buffers_size += lsmctx_aligned_size
...
security_release_secctx(&lsmctx) /* memset zeroes len */
...
sg_buf_end_offset = sg_buf_offset + extra_buffers_size
- ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */
security_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len
reads back as 0 and the subtraction contributes nothing, leaving
sg_buf_end_offset too large by the aligned secctx size on every
transaction to a txn_security_ctx node.
Each BINDER_TYPE_PTR object then derives buf_left = sg_buf_end_offset -
sg_buf_offset as the sole upper bound on its copy, so the inflated end
offset lets the copy run into the bytes that already hold the secctx.
The aligned size must therefore be cached before release rather than
re-read from the now-cleared field. Fix by caching it in
lsmctx_aligned_size at function scope when it is first computed and
subtracting lsmctx_aligned_size instead of re-reading lsmctx.len after
release. Reuse the same value for the earlier buf_offset computation.
References
Impacted products
| Vendor | Product | Version |
|---|
{
"affected": [
{
"affectedData": [
{
"defaultStatus": "unaffected",
"product": "Linux",
"programFiles": [
"drivers/android/binder.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"lessThan": "1228926e1e4d605cc74d9e675558982a6f2cf446",
"status": "affected",
"version": "6fba89813ccf333d2bc4d5caea04cd5f3c39eb50",
"versionType": "git"
},
{
"lessThan": "4257f45ee1fddd0558e77b62af8bb63fd87b2162",
"status": "affected",
"version": "6fba89813ccf333d2bc4d5caea04cd5f3c39eb50",
"versionType": "git"
},
{
"lessThan": "b34826e55aad3520ec813f1f367c11b24b29dc9f",
"status": "affected",
"version": "6fba89813ccf333d2bc4d5caea04cd5f3c39eb50",
"versionType": "git"
}
]
},
{
"defaultStatus": "affected",
"product": "Linux",
"programFiles": [
"drivers/android/binder.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"vendor": "Linux",
"versions": [
{
"status": "affected",
"version": "6.14"
},
{
"lessThan": "6.14",
"status": "unaffected",
"version": "0",
"versionType": "semver"
},
{
"lessThanOrEqual": "6.18.*",
"status": "unaffected",
"version": "6.18.40",
"versionType": "semver"
},
{
"lessThanOrEqual": "7.1.*",
"status": "unaffected",
"version": "7.1.5",
"versionType": "semver"
},
{
"lessThanOrEqual": "*",
"status": "unaffected",
"version": "7.2",
"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\nbinder: cache secctx size before release zeroes it\n\nbinder_transaction() bounds the scatter-gather buffer area with\nsg_buf_end_offset and subtracts the aligned LSM context size because\nthe secctx is written at the tail of that area. The subtraction reads\nlsmctx.len, but that field has already been cleared by the time the\nline runs:\n\n security_secid_to_secctx(secid, \u0026lsmctx) /* lsmctx.len set */\n lsmctx_aligned_size = ALIGN(lsmctx.len, sizeof(u64))\n extra_buffers_size += lsmctx_aligned_size\n ...\n security_release_secctx(\u0026lsmctx) /* memset zeroes len */\n ...\n sg_buf_end_offset = sg_buf_offset + extra_buffers_size\n - ALIGN(lsmctx.len, sizeof(u64)) /* ALIGN(0,8) */\n\nsecurity_release_secctx() does memset(cp, 0, sizeof(*cp)), so lsmctx.len\nreads back as 0 and the subtraction contributes nothing, leaving\nsg_buf_end_offset too large by the aligned secctx size on every\ntransaction to a txn_security_ctx node.\n\nEach BINDER_TYPE_PTR object then derives buf_left = sg_buf_end_offset -\nsg_buf_offset as the sole upper bound on its copy, so the inflated end\noffset lets the copy run into the bytes that already hold the secctx.\n\nThe aligned size must therefore be cached before release rather than\nre-read from the now-cleared field. Fix by caching it in\nlsmctx_aligned_size at function scope when it is first computed and\nsubtracting lsmctx_aligned_size instead of re-reading lsmctx.len after\nrelease. Reuse the same value for the earlier buf_offset computation."
}
],
"id": "CVE-2026-68458",
"lastModified": "2026-08-17T06:17:55.003",
"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": "2026-08-15T06:18:15.350",
"references": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/1228926e1e4d605cc74d9e675558982a6f2cf446"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/4257f45ee1fddd0558e77b62af8bb63fd87b2162"
},
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"url": "https://git.kernel.org/stable/c/b34826e55aad3520ec813f1f367c11b24b29dc9f"
}
],
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"vulnStatus": "Received"
}
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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.
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.
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