CVE-2026-74350

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ocfs2: validate fast symlink target during inode read ocfs2_validate_inode_block() already rejects several inconsistent self-contained dinodes before they are exposed to the rest of the filesystem. Fast symlinks need the same treatment. A zero-cluster symlink is treated as a fast symlink and later read through page_get_link() and ocfs2_fast_symlink_read_folio(). That path uses strnlen() on the inline payload and then copies len + 1 bytes into the folio. If a corrupt dinode stores an i_size that does not fit the inline area or omits the terminating NUL at i_size, that copy reads past the end of the inode block buffer. Reject zero-cluster symlink dinodes whose i_size exceeds the inline fast-symlink capacity or whose inline payload is not NUL-terminated exactly at i_size when the inode block is validated. This keeps malformed fast symlinks from reaching the read path. Validation reproduced this kernel report: KASAN use-after-free in ocfs2_fast_symlink_read_folio+0x12c/0x1f0 RIP: 0033:0x7f5c6d859aa7 Read of size 3905 Call trace: dump_stack_lvl+0x66/0xa0 (?:?) print_report+0xce/0x630 (?:?) ocfs2_fast_symlink_read_folio+0x12c/0x1f0 (fs/ocfs2/inode.c:?) srso_alias_return_thunk+0x5/0xfbef5 (?:?) __virt_addr_valid+0x19f/0x330 (?:?) kasan_report+0xe0/0x110 (?:?) kasan_check_range+0x105/0x1b0 (?:?) __asan_memcpy+0x23/0x60 (?:?) filemap_read_folio+0x27/0xe0 (?:?) filemap_read_folio+0x35/0xe0 (?:?) do_read_cache_folio+0x138/0x230 (?:?) __page_get_link+0x26/0x110 (?:?) page_get_link+0x2e/0x70 (?:?) vfs_readlink+0x15e/0x250 (?:?) touch_atime+0x4d/0x370 (?:?) do_readlinkat+0x186/0x200 (?:?) do_user_addr_fault+0x65a/0x890 (?:?) __x64_sys_readlink+0x46/0x60 (?:?) do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87) entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)

Severity

CRITICAL

CVSS score

9.8 (v3.1)

Vulnerability status

Received

Source identifier

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

Published

2026-08-15 06:22:36.270000

Last modified

2026-10-30 13:19:55.933000

View original CVE JSON

{
  "id": "CVE-2026-74350",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-08-15T06:22:36.270",
  "lastModified": "2026-10-30T13:19:55.933",
  "vulnStatus": "Received",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: validate fast symlink target during inode read\n\nocfs2_validate_inode_block() already rejects several inconsistent\nself-contained dinodes before they are exposed to the rest of the\nfilesystem.  Fast symlinks need the same treatment.\n\nA zero-cluster symlink is treated as a fast symlink and later read through\npage_get_link() and ocfs2_fast_symlink_read_folio().  That path uses\nstrnlen() on the inline payload and then copies len + 1 bytes into the\nfolio.  If a corrupt dinode stores an i_size that does not fit the inline\narea or omits the terminating NUL at i_size, that copy reads past the end\nof the inode block buffer.\n\nReject zero-cluster symlink dinodes whose i_size exceeds the inline\nfast-symlink capacity or whose inline payload is not NUL-terminated\nexactly at i_size when the inode block is validated.  This keeps malformed\nfast symlinks from reaching the read path.\n\nValidation reproduced this kernel report:\nKASAN use-after-free in ocfs2_fast_symlink_read_folio+0x12c/0x1f0\nRIP: 0033:0x7f5c6d859aa7\nRead of size 3905\nCall trace:\n  dump_stack_lvl+0x66/0xa0 (?:?)\n  print_report+0xce/0x630 (?:?)\n  ocfs2_fast_symlink_read_folio+0x12c/0x1f0 (fs/ocfs2/inode.c:?)\n  srso_alias_return_thunk+0x5/0xfbef5 (?:?)\n  __virt_addr_valid+0x19f/0x330 (?:?)\n  kasan_report+0xe0/0x110 (?:?)\n  kasan_check_range+0x105/0x1b0 (?:?)\n  __asan_memcpy+0x23/0x60 (?:?)\n  filemap_read_folio+0x27/0xe0 (?:?)\n  filemap_read_folio+0x35/0xe0 (?:?)\n  do_read_cache_folio+0x138/0x230 (?:?)\n  __page_get_link+0x26/0x110 (?:?)\n  page_get_link+0x2e/0x70 (?:?)\n  vfs_readlink+0x15e/0x250 (?:?)\n  touch_atime+0x4d/0x370 (?:?)\n  do_readlinkat+0x186/0x200 (?:?)\n  do_user_addr_fault+0x65a/0x890 (?:?)\n  __x64_sys_readlink+0x46/0x60 (?:?)\n  do_syscall_64+0x115/0x6a0 (arch/x86/entry/syscall_64.c:87)\n  entry_SYSCALL_64_after_hwframe+0x77/0x7f (?:?)"
    }
  ],
  "affected": [
    {
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
      "affectedData": [
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "unaffected",
          "programFiles": [
            "fs/ocfs2/inode.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "ea022dfb3c2a4680483b00eb2fecc9fc4f6091d1",
              "lessThan": "ed9f95ee3bbaea9b05808727eb86ea5e5ccf2b52",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ea022dfb3c2a4680483b00eb2fecc9fc4f6091d1",
              "lessThan": "dcabbf7da43825e23e5e89adccc1430faee1bce1",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ea022dfb3c2a4680483b00eb2fecc9fc4f6091d1",
              "lessThan": "030d4caae89977b80349df95523dfda1dfb10f73",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ea022dfb3c2a4680483b00eb2fecc9fc4f6091d1",
              "lessThan": "d94bf50756d7f80bb728ad58246376649e1035b6",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ea022dfb3c2a4680483b00eb2fecc9fc4f6091d1",
              "lessThan": "f9e2cb692b77a679b1f4cc2b7b277fa908586533",
              "versionType": "git",
              "status": "affected"
            },
            {
              "version": "ea022dfb3c2a4680483b00eb2fecc9fc4f6091d1",
              "lessThan": "e234973f286ed2e8961a24561ec91594ec3e3ff8",
              "versionType": "git",
              "status": "affected"
            }
          ]
        },
        {
          "vendor": "Linux",
          "product": "Linux",
          "defaultStatus": "affected",
          "programFiles": [
            "fs/ocfs2/inode.c"
          ],
          "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
          "versions": [
            {
              "version": "3.5",
              "status": "affected"
            },
            {
              "version": "0",
              "lessThan": "3.5",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.1.191",
              "lessThanOrEqual": "6.1.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.6.160",
              "lessThanOrEqual": "6.6.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.12.114",
              "lessThanOrEqual": "6.12.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "6.18.57",
              "lessThanOrEqual": "6.18.*",
              "versionType": "semver",
              "status": "unaffected"
            },
            {
              "version": "7.1.5",
              "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
      }
    ]
  },
  "references": [
    {
      "url": "https://git.kernel.org/stable/c/030d4caae89977b80349df95523dfda1dfb10f73",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/d94bf50756d7f80bb728ad58246376649e1035b6",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/dcabbf7da43825e23e5e89adccc1430faee1bce1",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/e234973f286ed2e8961a24561ec91594ec3e3ff8",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/ed9f95ee3bbaea9b05808727eb86ea5e5ccf2b52",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    },
    {
      "url": "https://git.kernel.org/stable/c/f9e2cb692b77a679b1f4cc2b7b277fa908586533",
      "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"
    }
  ]
}