CVE-2026-90176

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ksmbd: Do not skip lock checks for single-byte ranges check_lock_range() uses inclusive ranges. Its callers pass the end offset as start + length - 1, so start == end represents a valid single-byte range rather than an empty range. The start == end shortcut therefore skips mandatory byte-range lock checks for one-byte reads, writes, copychunk operations and one-byte truncate ranges. A conflicting lock covering that byte is not checked and the operation is allowed to proceed. Remove the shortcut. The truncate size == inode->i_size case is already handled by only calling check_lock_range() when the new size differs from the current file size.

Severity

HIGH

CVSS score

8.1 (v3.1)

Vulnerability status

Received

Source identifier

416baaa9-dc9f-4396-8d5f-8c081fb06d67

Published

2026-09-17 17:17:11.387000

Last modified

2026-10-19 09:19:07.570000

View original CVE JSON

{
  "id": "CVE-2026-90176",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-09-17T17:17:11.387",
  "lastModified": "2026-10-19T09:19:07.570",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nksmbd: Do not skip lock checks for single-byte ranges\n\ncheck_lock_range() uses inclusive ranges. Its callers pass the end\noffset as start + length - 1, so start == end represents a valid\nsingle-byte range rather than an empty range.\n\nThe start == end shortcut therefore skips mandatory byte-range lock\nchecks for one-byte reads, writes, copychunk operations and one-byte\ntruncate ranges. A conflicting lock covering that byte is not checked\nand the operation is allowed to proceed.\n\nRemove the shortcut. The truncate size == inode->i_size case is already\nhandled by only calling check_lock_range() when the new size differs\nfrom the current file size."
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/smb/server/vfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "52fcbb92e0d3acfd1448b2a43b6595d540da5295",
              "lessThan": "a89cc145832e81c32199d4ca2e1ea8bd51ed601d",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "da29cd197246c85c0473259f1cad897d9d28faea",
              "lessThan": "993e0158331d37c04da18efe551b5e1e35fb3078",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "a6f4cfa3783804336491e0edcb250c25f9b59d33",
              "lessThan": "f751d6e39d4c937c45f8fedc66699aa7d2d52288",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "571204e4758a528fbd67330bd4b0dfbdafb33dd8",
              "lessThan": "84c2d8e807ac489f5c91769293fb15dfdae8bae8",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5d510ac31626ed157d2182149559430350cf2104",
              "lessThan": "07a9e289ff7edcc004f58952405f8a65c4e37512",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "5d510ac31626ed157d2182149559430350cf2104",
              "lessThan": "d40c24634fe077a0dc91fd11fccf44ce12b454d5",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "6.1.160",
              "lessThan": "6.1.188",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "6.6.120",
              "lessThan": "6.6.157",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "6.12.64",
              "lessThan": "6.12.110",
              "versionType": "semver",
              "status": "affected"
            },
            {
              "version": "6.18.3",
              "lessThan": "6.18.52",
              "versionType": "semver",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/smb/server/vfs.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "6.19",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "6.19",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.188",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.157",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.110",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.52",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.2.6",
              "lessThanOrEqual": "7.2.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.3",
              "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:L/UI:N/S:U/C:H/I:H/A:N",
          "baseScore": 8.1,
          "baseSeverity": "HIGH",
          "attackVector": "NETWORK",
          "attackComplexity": "LOW",
          "privilegesRequired": "LOW",
          "userInteraction": "NONE",
          "scope": "UNCHANGED",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "availabilityImpact": "NONE"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.2
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/07a9e289ff7edcc004f58952405f8a65c4e37512",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/84c2d8e807ac489f5c91769293fb15dfdae8bae8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/993e0158331d37c04da18efe551b5e1e35fb3078",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/a89cc145832e81c32199d4ca2e1ea8bd51ed601d",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d40c24634fe077a0dc91fd11fccf44ce12b454d5",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f751d6e39d4c937c45f8fedc66699aa7d2d52288",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}