FKIE_CVE-2026-64317

Vulnerability from fkie_nvd - Published: 2026-07-25 10:17 - Updated: 2026-07-27 05:16
Severity
7.1 (High) - CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H
Summary
In the Linux kernel, the following vulnerability has been resolved: isofs: bound Rock Ridge symlink components to the SL record get_symlink_chunk() and the SL handling in parse_rock_ridge_inode_internal() walk the variable-length components of a Rock Ridge "SL" (symbolic link) record. Each component is a two-byte header (flags, len) followed by len bytes of text, so it occupies slp->len + 2 bytes. Both loops read slp->len and advance to the next component, and get_symlink_chunk() additionally does memcpy(rpnt, slp->text, slp->len), but neither checks that the component lies within the SL record before dereferencing it. A crafted SL record whose component declares a len that runs past the record (rr->len) therefore triggers an out-of-bounds read of up to 255 bytes. When the record sits at the tail of its backing buffer - for example a small kmalloc()ed continuation block reached through a CE record - the read crosses the allocation; get_symlink_chunk() then copies the out-of-bounds bytes into the symlink body returned to user space by readlink(), disclosing adjacent kernel memory. ISO 9660 images are routinely mounted from untrusted removable media - desktop environments auto-mount them (e.g. via udisks2) without CAP_SYS_ADMIN - so the record contents are attacker-controlled. Reject any component that does not fit in the remaining record bytes before using it. In get_symlink_chunk() return NULL, like the existing output-buffer (plimit) checks, so a malformed record makes readlink() fail with -EIO rather than silently returning a truncated target; in parse_rock_ridge_inode_internal() stop the inode-size walk.
References
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/1015e1c4b2fadd9c09704e24738e46598778c869
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/36fe7d25dbc40da0c6b1dd4513a4f69ac6164eee
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/5fa1d6a5ec2356d2107dead614437c66fa7138b1
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/6bf41db09ef935d76fcc84ccf213b42c18de95ee
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/9830725078c8483c6831ec10222ae724806ea36b
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/a22cb6bb54dc167047ea9e70d97dfbc2c15649e3
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b5699642640d6cff357638738c5293985cd5a53d
416baaa9-dc9f-4396-8d5f-8c081fb06d67https://git.kernel.org/stable/c/b736b12108fd116c41777628f5a333791604df26
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/isofs/rock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "lessThan": "1015e1c4b2fadd9c09704e24738e46598778c869",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "36fe7d25dbc40da0c6b1dd4513a4f69ac6164eee",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "a22cb6bb54dc167047ea9e70d97dfbc2c15649e3",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "b736b12108fd116c41777628f5a333791604df26",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "6bf41db09ef935d76fcc84ccf213b42c18de95ee",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "b5699642640d6cff357638738c5293985cd5a53d",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "9830725078c8483c6831ec10222ae724806ea36b",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            },
            {
              "lessThan": "5fa1d6a5ec2356d2107dead614437c66fa7138b1",
              "status": "affected",
              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
            }
          ]
        },
        {
          "defaultStatus": "affected",
          "product": "Linux",
          "programFiles": [
            "fs/isofs/rock.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "vendor": "Linux",
          "versions": [
            {
              "status": "affected",
              "version": "2.6.12"
            },
            {
              "lessThan": "2.6.12",
              "status": "unaffected",
              "version": "0",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.261",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.212",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.178",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.145",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.96",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.39",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "7.1.*",
              "status": "unaffected",
              "version": "7.1.4",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "7.2-rc1",
              "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\nisofs: bound Rock Ridge symlink components to the SL record\n\nget_symlink_chunk() and the SL handling in\nparse_rock_ridge_inode_internal() walk the variable-length components of\na Rock Ridge \"SL\" (symbolic link) record.  Each component is a two-byte\nheader (flags, len) followed by len bytes of text, so it occupies\nslp-\u003elen + 2 bytes.  Both loops read slp-\u003elen and advance to the next\ncomponent, and get_symlink_chunk() additionally does\nmemcpy(rpnt, slp-\u003etext, slp-\u003elen), but neither checks that the component\nlies within the SL record before dereferencing it.\n\nA crafted SL record whose component declares a len that runs past the\nrecord (rr-\u003elen) therefore triggers an out-of-bounds read of up to 255\nbytes.  When the record sits at the tail of its backing buffer - for\nexample a small kmalloc()ed continuation block reached through a CE\nrecord - the read crosses the allocation; get_symlink_chunk() then\ncopies the out-of-bounds bytes into the symlink body returned to user\nspace by readlink(), disclosing adjacent kernel memory.\n\nISO 9660 images are routinely mounted from untrusted removable media -\ndesktop environments auto-mount them (e.g. via udisks2) without\nCAP_SYS_ADMIN - so the record contents are attacker-controlled.\n\nReject any component that does not fit in the remaining record bytes\nbefore using it.  In get_symlink_chunk() return NULL, like the existing\noutput-buffer (plimit) checks, so a malformed record makes readlink()\nfail with -EIO rather than silently returning a truncated target; in\nparse_rock_ridge_inode_internal() stop the inode-size walk."
    }
  ],
  "id": "CVE-2026-64317",
  "lastModified": "2026-07-27T05:16:41.640",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "LOCAL",
          "availabilityImpact": "HIGH",
          "baseScore": 7.1,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "NONE",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 1.8,
        "impactScore": 5.2,
        "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "type": "Secondary"
      }
    ]
  },
  "published": "2026-07-25T10:17:13.010",
  "references": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/1015e1c4b2fadd9c09704e24738e46598778c869"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/36fe7d25dbc40da0c6b1dd4513a4f69ac6164eee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/5fa1d6a5ec2356d2107dead614437c66fa7138b1"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/6bf41db09ef935d76fcc84ccf213b42c18de95ee"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/9830725078c8483c6831ec10222ae724806ea36b"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/a22cb6bb54dc167047ea9e70d97dfbc2c15649e3"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b5699642640d6cff357638738c5293985cd5a53d"
    },
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "url": "https://git.kernel.org/stable/c/b736b12108fd116c41777628f5a333791604df26"
    }
  ],
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "vulnStatus": "Received"
}



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