Vulnerability-Lookup

CVE-2026-23238 (GCVE-0-2026-23238)

Vulnerability from cvelistv5 – Published: 2026-03-04 14:38 – Updated: 2026-03-04 14:38

Title

romfs: check sb_set_blocksize() return value

Summary

In the Linux kernel, the following vulnerability has been resolved: romfs: check sb_set_blocksize() return value romfs_fill_super() ignores the return value of sb_set_blocksize(), which can fail if the requested block size is incompatible with the block device's configuration. This can be triggered by setting a loop device's block size larger than PAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs filesystem on that device. When sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the device has logical_block_size=32768, bdev_validate_blocksize() fails because the requested size is smaller than the device's logical block size. sb_set_blocksize() returns 0 (failure), but romfs ignores this and continues mounting. The superblock's block size remains at the device's logical block size (32768). Later, when sb_bread() attempts I/O with this oversized block size, it triggers a kernel BUG in folio_set_bh(): kernel BUG at fs/buffer.c:1582! BUG_ON(size > PAGE_SIZE); Fix by checking the return value of sb_set_blocksize() and failing the mount with -EINVAL if it returns 0.

Severity ?

No CVSS data available.

Assigner

Linux

References

URL

Tags

	https://git.kernel.org/stable/c/a381f0f61b35c8894…
	https://git.kernel.org/stable/c/f2521ab1f63a8c244…
	https://git.kernel.org/stable/c/2c5829cd8fbbc9156…
	https://git.kernel.org/stable/c/cbd9931e645682206…
	https://git.kernel.org/stable/c/9b203b8ddd7359270…
	https://git.kernel.org/stable/c/4b71ad7676564a94e…
	https://git.kernel.org/stable/c/ab7ad7abb3660c58f…

Impacted products

Vendor

Product

Version

Linux

Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < a381f0f61b35c8894b0bd0d6acef2d8f9b08b244 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < f2521ab1f63a8c244f06a080319e5ff9a2e1bd95 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 2c5829cd8fbbc91568c520b666898f57cdcb8cf6 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < cbd9931e6456822067725354d83446c5bb813030 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 9b203b8ddd7359270e8a694d0584743555128e2c (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < 4b71ad7676564a94ec5f7d18298f51e8ae53db73 (git)
Affected: 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 , < ab7ad7abb3660c58ffffdf07ff3bb976e7e0afa0 (git)

Linux

Unaffected: 5.10.251 , ≤ 5.10.* (semver)
Unaffected: 5.15.201 , ≤ 5.15.* (semver)
Unaffected: 6.1.164 , ≤ 6.1.* (semver)
Unaffected: 6.6.127 , ≤ 6.6.* (semver)
Unaffected: 6.12.74 , ≤ 6.12.* (semver)
Unaffected: 6.18.13 , ≤ 6.18.* (semver)
Unaffected: 6.19 , ≤ * (original_commit_for_fix)

Show details on NVD website

JSON

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{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "Linux",
          "programFiles": [
            "fs/romfs/super.c"
          ],
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          "vendor": "Linux",
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              "status": "affected",
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              "versionType": "git"
            },
            {
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              "versionType": "git"
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              "versionType": "git"
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              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
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            {
              "lessThan": "4b71ad7676564a94ec5f7d18298f51e8ae53db73",
              "status": "affected",
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              "versionType": "git"
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              "version": "1da177e4c3f41524e886b7f1b8a0c1fc7321cac2",
              "versionType": "git"
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        },
        {
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          "programFiles": [
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          ],
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          "vendor": "Linux",
          "versions": [
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              "lessThanOrEqual": "5.10.*",
              "status": "unaffected",
              "version": "5.10.251",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "5.15.*",
              "status": "unaffected",
              "version": "5.15.201",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.1.*",
              "status": "unaffected",
              "version": "6.1.164",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.6.*",
              "status": "unaffected",
              "version": "6.6.127",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.12.*",
              "status": "unaffected",
              "version": "6.12.74",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "6.18.*",
              "status": "unaffected",
              "version": "6.18.13",
              "versionType": "semver"
            },
            {
              "lessThanOrEqual": "*",
              "status": "unaffected",
              "version": "6.19",
              "versionType": "original_commit_for_fix"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
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                  "versionEndExcluding": "5.10.251",
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                  "versionEndExcluding": "5.15.201",
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              "negate": false,
              "operator": "OR"
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      "descriptions": [
        {
          "lang": "en",
          "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nromfs: check sb_set_blocksize() return value\n\nromfs_fill_super() ignores the return value of sb_set_blocksize(), which\ncan fail if the requested block size is incompatible with the block\ndevice\u0027s configuration.\n\nThis can be triggered by setting a loop device\u0027s block size larger than\nPAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs\nfilesystem on that device.\n\nWhen sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the\ndevice has logical_block_size=32768, bdev_validate_blocksize() fails\nbecause the requested size is smaller than the device\u0027s logical block\nsize. sb_set_blocksize() returns 0 (failure), but romfs ignores this and\ncontinues mounting.\n\nThe superblock\u0027s block size remains at the device\u0027s logical block size\n(32768). Later, when sb_bread() attempts I/O with this oversized block\nsize, it triggers a kernel BUG in folio_set_bh():\n\n    kernel BUG at fs/buffer.c:1582!\n    BUG_ON(size \u003e PAGE_SIZE);\n\nFix by checking the return value of sb_set_blocksize() and failing the\nmount with -EINVAL if it returns 0."
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-03-04T14:38:42.477Z",
        "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
        "shortName": "Linux"
      },
      "references": [
        {
          "url": "https://git.kernel.org/stable/c/a381f0f61b35c8894b0bd0d6acef2d8f9b08b244"
        },
        {
          "url": "https://git.kernel.org/stable/c/f2521ab1f63a8c244f06a080319e5ff9a2e1bd95"
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        },
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        {
          "url": "https://git.kernel.org/stable/c/ab7ad7abb3660c58ffffdf07ff3bb976e7e0afa0"
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      ],
      "title": "romfs: check sb_set_blocksize() return value",
      "x_generator": {
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    "cveId": "CVE-2026-23238",
    "datePublished": "2026-03-04T14:38:42.477Z",
    "dateReserved": "2026-01-13T15:37:45.989Z",
    "dateUpdated": "2026-03-04T14:38:42.477Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-23238\",\"sourceIdentifier\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\",\"published\":\"2026-03-04T15:16:14.530\",\"lastModified\":\"2026-03-04T18:08:05.730\",\"vulnStatus\":\"Awaiting Analysis\",\"cveTags\":[],\"descriptions\":[{\"lang\":\"en\",\"value\":\"In the Linux kernel, the following vulnerability has been resolved:\\n\\nromfs: check sb_set_blocksize() return value\\n\\nromfs_fill_super() ignores the return value of sb_set_blocksize(), which\\ncan fail if the requested block size is incompatible with the block\\ndevice\u0027s configuration.\\n\\nThis can be triggered by setting a loop device\u0027s block size larger than\\nPAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs\\nfilesystem on that device.\\n\\nWhen sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the\\ndevice has logical_block_size=32768, bdev_validate_blocksize() fails\\nbecause the requested size is smaller than the device\u0027s logical block\\nsize. sb_set_blocksize() returns 0 (failure), but romfs ignores this and\\ncontinues mounting.\\n\\nThe superblock\u0027s block size remains at the device\u0027s logical block size\\n(32768). Later, when sb_bread() attempts I/O with this oversized block\\nsize, it triggers a kernel BUG in folio_set_bh():\\n\\n    kernel BUG at fs/buffer.c:1582!\\n    BUG_ON(size \u003e PAGE_SIZE);\\n\\nFix by checking the return value of sb_set_blocksize() and failing the\\nmount with -EINVAL if it returns 0.\"}],\"metrics\":{},\"references\":[{\"url\":\"https://git.kernel.org/stable/c/2c5829cd8fbbc91568c520b666898f57cdcb8cf6\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/4b71ad7676564a94ec5f7d18298f51e8ae53db73\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/9b203b8ddd7359270e8a694d0584743555128e2c\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/a381f0f61b35c8894b0bd0d6acef2d8f9b08b244\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/ab7ad7abb3660c58ffffdf07ff3bb976e7e0afa0\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/cbd9931e6456822067725354d83446c5bb813030\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"},{\"url\":\"https://git.kernel.org/stable/c/f2521ab1f63a8c244f06a080319e5ff9a2e1bd95\",\"source\":\"416baaa9-dc9f-4396-8d5f-8c081fb06d67\"}]}}"
  }
}

GHSA-WJ4M-W3QM-XPCH

Vulnerability from github – Published: 2026-03-04 15:30 – Updated: 2026-03-04 15:30

Details

In the Linux kernel, the following vulnerability has been resolved:

romfs: check sb_set_blocksize() return value

romfs_fill_super() ignores the return value of sb_set_blocksize(), which can fail if the requested block size is incompatible with the block device's configuration.

This can be triggered by setting a loop device's block size larger than PAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs filesystem on that device.

When sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the device has logical_block_size=32768, bdev_validate_blocksize() fails because the requested size is smaller than the device's logical block size. sb_set_blocksize() returns 0 (failure), but romfs ignores this and continues mounting.

The superblock's block size remains at the device's logical block size (32768). Later, when sb_bread() attempts I/O with this oversized block size, it triggers a kernel BUG in folio_set_bh():

kernel BUG at fs/buffer.c:1582!
BUG_ON(size > PAGE_SIZE);

Fix by checking the return value of sb_set_blocksize() and failing the mount with -EINVAL if it returns 0.

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-23238"
  ],
  "database_specific": {
    "cwe_ids": [],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-03-04T15:16:14Z",
    "severity": null
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nromfs: check sb_set_blocksize() return value\n\nromfs_fill_super() ignores the return value of sb_set_blocksize(), which\ncan fail if the requested block size is incompatible with the block\ndevice\u0027s configuration.\n\nThis can be triggered by setting a loop device\u0027s block size larger than\nPAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs\nfilesystem on that device.\n\nWhen sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the\ndevice has logical_block_size=32768, bdev_validate_blocksize() fails\nbecause the requested size is smaller than the device\u0027s logical block\nsize. sb_set_blocksize() returns 0 (failure), but romfs ignores this and\ncontinues mounting.\n\nThe superblock\u0027s block size remains at the device\u0027s logical block size\n(32768). Later, when sb_bread() attempts I/O with this oversized block\nsize, it triggers a kernel BUG in folio_set_bh():\n\n    kernel BUG at fs/buffer.c:1582!\n    BUG_ON(size \u003e PAGE_SIZE);\n\nFix by checking the return value of sb_set_blocksize() and failing the\nmount with -EINVAL if it returns 0.",
  "id": "GHSA-wj4m-w3qm-xpch",
  "modified": "2026-03-04T15:30:36Z",
  "published": "2026-03-04T15:30:36Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-23238"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/2c5829cd8fbbc91568c520b666898f57cdcb8cf6"
    },
    {
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      "url": "https://git.kernel.org/stable/c/4b71ad7676564a94ec5f7d18298f51e8ae53db73"
    },
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      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/9b203b8ddd7359270e8a694d0584743555128e2c"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/a381f0f61b35c8894b0bd0d6acef2d8f9b08b244"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/ab7ad7abb3660c58ffffdf07ff3bb976e7e0afa0"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/cbd9931e6456822067725354d83446c5bb813030"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/f2521ab1f63a8c244f06a080319e5ff9a2e1bd95"
    }
  ],
  "schema_version": "1.4.0",
  "severity": []
}

Sightings

Author	Source	Type	Date

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Detection rules are retrieved from Rulezet.

Action not permitted

CVE-2026-23238 (GCVE-0-2026-23238)

GHSA-WJ4M-W3QM-XPCH

Tags

Sightings

Nomenclature