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smb: client: fix create context out-of-bounds reads

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix create context out-of-bounds reads smb2_parse_contexts() validates the complete create-context area but does not limit each record to its Next field before dispatching it. A malformed chain can therefore expose bytes beyond the current context to a handler. The QFid handler also used a full response-structure cast although it only reads DiskFileId. The SMB2/SMB3 lease parsers made the same layout assumption: they read LeaseState and LeaseFlags at canonical offsets rather than at DataOffset. A valid non-canonical DataOffset could therefore yield unrelated in-bounds data, while a short DataLength was still accepted. Limit each context to its Next value, reject offsets before the context header, and reject malformed chains. Bound the name range by the current context and do not dispatch a known handler when DataLength is zero. Read the QFid DiskFileId only when the context data covers that field. Parse the lease context from DataOffset and require DataLength to match the v1 or v2 lease_context size used by ksmbd. A size mismatch skips lease parsing without failing the open.

Announced Source revision 1
Original source ↗

CVE-2026-98454

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: cve:CVE-2026-98454

Linux

Source reference: /containers/cna/affected/0/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Linux

Source reference: /containers/cna/affected/1/product

Affected versions
Not stated in this record
Fixed versions
Not stated in this record
Prerequisites
Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "b8c32dbb0deb287a5fcb78251e4eae6c7275760d",
        "lessThan": "e4c49012708c917eafd9c27054b02d0f8b30fe64",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b8c32dbb0deb287a5fcb78251e4eae6c7275760d",
        "lessThan": "28bc9a871799363afa3139e961a8e3684feb8704",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b8c32dbb0deb287a5fcb78251e4eae6c7275760d",
        "lessThan": "05a7fd80024ff32b9b40ab1478bb172eeab1c386",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b8c32dbb0deb287a5fcb78251e4eae6c7275760d",
        "lessThan": "cecc5399987e73a528ce2b662eeb54af69163cbd",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "b8c32dbb0deb287a5fcb78251e4eae6c7275760d",
        "lessThan": "67f4c1c6a1b51e203d986779299824d1c2c590a6",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "fs/smb/client/smb2ops.c",
      "fs/smb/client/smb2pdu.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.7"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.7",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.6.158",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.112",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.55",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.9",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/smb/client/smb2ops.c",
      "fs/smb/client/smb2pdu.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-98454

Source reference: /cveMetadata/cveId

Publisher severity

high

Source reference: /containers/cna/metrics

Event
#55594 · Revision 1
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Publisher date
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