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ext4: convert inline data to extents when truncate exceeds inline size

Type: advisorySource: Official CVE List1 source record

In the Linux kernel, the following vulnerability has been resolved: ext4: convert inline data to extents when truncate exceeds inline size Add a check in ext4_setattr() to convert files from inline data storage to extent-based storage when truncate() grows the file size beyond the inline capacity. This prevents the filesystem from entering an inconsistent state where the inline data flag is set but the file size exceeds what can be stored inline. Without this fix, the following sequence causes a kernel BUG_ON(): 1. Mount filesystem with inode that has inline flag set and small size 2. truncate(file, 50MB) - grows size but inline flag remains set 3. sendfile() attempts to write data 4. ext4_write_inline_data() hits BUG_ON(write_size > inline_capacity) The crash occurs because ext4_write_inline_data() expects inline storage to accommodate the write, but the actual inline capacity (~60 bytes for i_block + ~96 bytes for xattrs) is far smaller than the file size and write request. The fix checks if the new size from setattr exceeds the inode's actual inline capacity (EXT4_I(inode)->i_inline_size) and converts the file to extent-based storage before proceeding with the size change. This addresses the root cause by ensuring the inline data flag and file size remain consistent during truncate operations.

Announced Source revision 1
Original source ↗

CVE-2026-31452

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-2026-31452

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": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "110d7ef602659ce4d7947c5480f7ca2779696aaf",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "f53a5d9f32924bc2a810d2df243b7714da58b636",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "c047332be7195833a5c5126816c2502df8269fe4",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "699bac4d4c951974d55b045c983d1de777215949",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "7920dcc571cef3d8aa9ee109c136125d61d41669",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "93cb2d103e5c707de0f7ad58a39b7f0fddc27aa6",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "07c1a31af18290054da3d18221b8bf58983c5d3a",
        "versionType": "git"
      },
      {
        "status": "affected",
        "version": "67cf5b09a46f72e048501b84996f2f77bc42e947",
        "lessThan": "ed9356a30e59c7cc3198e7fc46cfedf3767b9b17",
        "versionType": "git"
      }
    ],
    "programFiles": [
      "fs/ext4/inode.c"
    ],
    "defaultStatus": "unaffected"
  },
  {
    "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git",
    "vendor": "Linux",
    "product": "Linux",
    "versions": [
      {
        "status": "affected",
        "version": "3.8"
      },
      {
        "status": "unaffected",
        "version": "0",
        "lessThan": "3.8",
        "versionType": "semver"
      },
      {
        "status": "unaffected",
        "version": "5.10.253",
        "versionType": "semver",
        "lessThanOrEqual": "5.10.*"
      },
      {
        "status": "unaffected",
        "version": "5.15.203",
        "versionType": "semver",
        "lessThanOrEqual": "5.15.*"
      },
      {
        "status": "unaffected",
        "version": "6.1.168",
        "versionType": "semver",
        "lessThanOrEqual": "6.1.*"
      },
      {
        "status": "unaffected",
        "version": "6.6.131",
        "versionType": "semver",
        "lessThanOrEqual": "6.6.*"
      },
      {
        "status": "unaffected",
        "version": "6.12.80",
        "versionType": "semver",
        "lessThanOrEqual": "6.12.*"
      },
      {
        "status": "unaffected",
        "version": "6.18.21",
        "versionType": "semver",
        "lessThanOrEqual": "6.18.*"
      },
      {
        "status": "unaffected",
        "version": "6.19.11",
        "versionType": "semver",
        "lessThanOrEqual": "6.19.*"
      },
      {
        "status": "unaffected",
        "version": "7.0",
        "versionType": "original_commit_for_fix",
        "lessThanOrEqual": "*"
      }
    ],
    "programFiles": [
      "fs/ext4/inode.c"
    ],
    "defaultStatus": "affected"
  }
]
Related CVEs
CVE-2026-31452

Source reference: /cveMetadata/cveId

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Event
#28280 · Revision 1
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