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smb: client: fix ALIGN() overflow in symlink_data() error context loop

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: smb: client: fix ALIGN() overflow in symlink_data() error context loop The check added by commit 7d9a7f1f96cd ("smb/client: fix possible infinite loop and oob read in symlink_data()") compared the post-ALIGN length against the remaining buffer, but ALIGN() itself can overflow: for ErrorDataLength near UINT32_MAX (e.g. 0xFFFFFFF9), ALIGN(x, 8) wraps to 0, so the subsequent bounds check passes, and the loop advances by zero bytes leaving 'p' pointing into stale data. Fix by checking the raw ErrorDataLength against the remaining space before applying ALIGN(), then checking again after. Since raw_len is bounded by the buffer, raw_len + 7 cannot overflow, so the second check is an exact post-alignment bounds guard.

Announced Source revision 1
Original source ↗

CVE-2026-89634

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-2026-89634

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": "76894f3e2f71177747b8b4763fb180e800279585",
        "lessThan": "2b4a25baa0b936fef6915c0459925077b324ecaf",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "76894f3e2f71177747b8b4763fb180e800279585",
        "lessThan": "b89d678f9eafcf8d74885983166ba26b40a04ea0",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "76894f3e2f71177747b8b4763fb180e800279585",
        "lessThan": "657372ba6ea50b4474d2a6a610097eae8cd1f3e9",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "76894f3e2f71177747b8b4763fb180e800279585",
        "lessThan": "1f824f61d1df52392eaf0b74dfa5659d724fde30",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "76894f3e2f71177747b8b4763fb180e800279585",
        "lessThan": "62a3025983c8c735a3c6fc85a59316f31b59af07",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "76894f3e2f71177747b8b4763fb180e800279585",
        "lessThan": "62656b024efc21c3230eade1a847f25871c3d2bb",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "2d046892a493d9760c35fdaefc3017f27f91b621",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "6.0.16",
        "lessThan": "6.1",
        "versionType": "semver"
      }
    ],
    "programFiles": [
      "fs/smb/client/smb2file.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "6.1"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "6.1",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "6.1.188",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.157",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.109",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.50",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "7.2.4",
        "versionType": "semver",
        "lessThanOrEqual": "7.2.*"
      },
      {
        "status": "unaffected",
        "version": "7.3",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/smb/client/smb2file.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-89634

Source reference: /cveMetadata/cveId

Publisher severity

critical

Source reference: /containers/cna/metrics

Event
#35134 · Revision 1
Added to Heist Feed
Publisher date
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