CVE-2026-68156
Full vulnerability record from the local CVENow database.
Description
In the Linux kernel, the following vulnerability has been resolved: libceph: refresh auth->authorizer_buf{,_len} after authorizer update ceph_x_create_authorizer() caches au->buf->vec.iov_base and au->buf->vec.iov_len in struct ceph_auth_handshake. These cached values are then used by the messenger connect code when sending the authorizer. ceph_x_update_authorizer() can rebuild the authorizer when a newer service ticket is available. If the rebuilt authorizer no longer fits in the existing buffer, ceph_x_build_authorizer() drops its reference to au->buf and allocates a new one. If this is the final reference, ceph_buffer_put() frees the old ceph_buffer and its vec.iov_base, but auth->authorizer_buf still points at that freed memory. A subsequent msgr1 reconnect can therefore queue the stale pointer and trigger a KASAN slab-use-after-free in _copy_from_iter() while tcp_sendmsg() copies the authorizer. Refresh auth->authorizer_buf and auth->authorizer_buf_len after a successful authorizer rebuild so the messenger sends the current buffer.
Severity
CRITICAL
CVSS score
9.8
(v3.1)
Vulnerability status
Received
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-08-10 13:20:01.780000
Last modified
2026-10-19 21:17:55.677000
View original CVE JSON
{
"id": "CVE-2026-68156",
"sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"published": "2026-08-10T13:20:01.780",
"lastModified": "2026-10-19T21:17:55.677",
"vulnStatus": "Received",
"cveTags": [],
"descriptions": [
{
"lang": "en",
"value": "In the Linux kernel, the following vulnerability has been resolved:\n\nlibceph: refresh auth->authorizer_buf{,_len} after authorizer update\n\nceph_x_create_authorizer() caches au->buf->vec.iov_base and\nau->buf->vec.iov_len in struct ceph_auth_handshake. These\ncached values are then used by the messenger connect code when\nsending the authorizer.\n\nceph_x_update_authorizer() can rebuild the authorizer when a newer\nservice ticket is available. If the rebuilt authorizer no longer\nfits in the existing buffer, ceph_x_build_authorizer() drops its\nreference to au->buf and allocates a new one. If this is the final\nreference, ceph_buffer_put() frees the old ceph_buffer and its\nvec.iov_base, but auth->authorizer_buf still points at that freed\nmemory.\n\nA subsequent msgr1 reconnect can therefore queue the stale pointer\nand trigger a KASAN slab-use-after-free in _copy_from_iter() while\ntcp_sendmsg() copies the authorizer.\n\nRefresh auth->authorizer_buf and auth->authorizer_buf_len after a\nsuccessful authorizer rebuild so the messenger sends the current\nbuffer."
}
],
"affected": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"affectedData": [
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "unaffected",
"programFiles": [
"net/ceph/auth_x.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
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{
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{
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},
{
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},
{
"version": "3.9.7",
"lessThan": "3.10",
"versionType": "semver",
"status": "affected"
}
]
},
{
"vendor": "Linux",
"product": "Linux",
"defaultStatus": "affected",
"programFiles": [
"net/ceph/auth_x.c"
],
"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
"versions": [
{
"version": "3.10",
"status": "affected"
},
{
"version": "0",
"lessThan": "3.10",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.10.265",
"lessThanOrEqual": "5.10.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "5.15.216",
"lessThanOrEqual": "5.15.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.1.183",
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"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.6.148",
"lessThanOrEqual": "6.6.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.12.101",
"lessThanOrEqual": "6.12.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "6.18.42",
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"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.1.6",
"lessThanOrEqual": "7.1.*",
"versionType": "semver",
"status": "unaffected"
},
{
"version": "7.2",
"lessThanOrEqual": "*",
"versionType": "original_commit_for_fix",
"status": "unaffected"
}
]
}
]
}
],
"metrics": {
"cvssMetricV31": [
{
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
"type": "Secondary",
"cvssData": {
"version": "3.1",
"vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"baseScore": 9.8,
"baseSeverity": "CRITICAL",
"attackVector": "NETWORK",
"attackComplexity": "LOW",
"privilegesRequired": "NONE",
"userInteraction": "NONE",
"scope": "UNCHANGED",
"confidentialityImpact": "HIGH",
"integrityImpact": "HIGH",
"availabilityImpact": "HIGH"
},
"exploitabilityScore": 3.9,
"impactScore": 5.9
}
],
"ssvcV203": [
{
"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"ssvcData": {
"timestamp": "2026-10-16T15:45:09.780823Z",
"id": "CVE-2026-68156",
"options": [
{
"exploitation": "none"
},
{
"automatable": "yes"
},
{
"technicalImpact": "total"
}
],
"role": "CISA Coordinator",
"version": "2.0.3"
}
}
]
},
"weaknesses": [
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"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
"type": "Secondary",
"description": [
{
"lang": "en",
"value": "CWE-416"
}
]
}
],
"references": [
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"url": "https://git.kernel.org/stable/c/0060ec912292a550198d8d18ac95b433c92a7091",
"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
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}