GHSA-V76Q-G5WV-JJW6

Vulnerability from github – Published: 2026-05-06 12:30 – Updated: 2026-05-08 15:31
VLAI?
Details

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

ocfs2: fix out-of-bounds write in ocfs2_write_end_inline

KASAN reports a use-after-free write of 4086 bytes in ocfs2_write_end_inline, called from ocfs2_write_end_nolock during a copy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on a loop device. The actual bug is an out-of-bounds write past the inode block buffer, not a true use-after-free. The write overflows into an adjacent freed page, which KASAN reports as UAF.

The root cause is that ocfs2_try_to_write_inline_data trusts the on-disk id_count field to determine whether a write fits in inline data. On a corrupted filesystem, id_count can exceed the physical maximum inline data capacity, causing writes to overflow the inode block buffer.

Call trace (crash path):

vfs_copy_file_range (fs/read_write.c:1634) do_splice_direct splice_direct_to_actor iter_file_splice_write ocfs2_file_write_iter generic_perform_write ocfs2_write_end ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949) ocfs2_write_end_inline (fs/ocfs2/aops.c:1915) memcpy_from_folio <-- KASAN: write OOB

So add id_count upper bound check in ocfs2_validate_inode_block() to alongside the existing i_size check to fix it.

Severity ?
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
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{
  "affected": [],
  "aliases": [
    "CVE-2026-43075"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-787"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-05-06T10:16:20Z",
    "severity": "HIGH"
  },
  "details": "In the Linux kernel, the following vulnerability has been resolved:\n\nocfs2: fix out-of-bounds write in ocfs2_write_end_inline\n\nKASAN reports a use-after-free write of 4086 bytes in\nocfs2_write_end_inline, called from ocfs2_write_end_nolock during a\ncopy_file_range splice fallback on a corrupted ocfs2 filesystem mounted on\na loop device.  The actual bug is an out-of-bounds write past the inode\nblock buffer, not a true use-after-free.  The write overflows into an\nadjacent freed page, which KASAN reports as UAF.\n\nThe root cause is that ocfs2_try_to_write_inline_data trusts the on-disk\nid_count field to determine whether a write fits in inline data.  On a\ncorrupted filesystem, id_count can exceed the physical maximum inline data\ncapacity, causing writes to overflow the inode block buffer.\n\nCall trace (crash path):\n\n   vfs_copy_file_range (fs/read_write.c:1634)\n     do_splice_direct\n       splice_direct_to_actor\n         iter_file_splice_write\n           ocfs2_file_write_iter\n             generic_perform_write\n               ocfs2_write_end\n                 ocfs2_write_end_nolock (fs/ocfs2/aops.c:1949)\n                   ocfs2_write_end_inline (fs/ocfs2/aops.c:1915)\n                     memcpy_from_folio     \u003c-- KASAN: write OOB\n\nSo add id_count upper bound check in ocfs2_validate_inode_block() to\nalongside the existing i_size check to fix it.",
  "id": "GHSA-v76q-g5wv-jjw6",
  "modified": "2026-05-08T15:31:15Z",
  "published": "2026-05-06T12:30:26Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-43075"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/0c1af902223b6fcedb60904ca0b551254686c7b9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/69d3c69ade1e4285ab4ca48fe7acee0767e65604"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/7bc5da4842bed3252d26e742213741a4d0ac1b14"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/947f953978b0d9463498d548d0f054f5a75be2e9"
    },
    {
      "type": "WEB",
      "url": "https://git.kernel.org/stable/c/e2c9dc6b6e96f3585f2a1062ca3374a52db0938f"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ]
}


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