GHSA-2Q7W-RGHX-VWH8
Vulnerability from github – Published: 2026-07-19 12:30 – Updated: 2026-07-24 15:32In the Linux kernel, the following vulnerability has been resolved:
f2fs: validate orphan inode entry count
f2fs_recover_orphan_inodes() trusts the orphan block entry_count when replaying orphan inodes from the checkpoint pack. A corrupted entry_count larger than F2FS_ORPHANS_PER_BLOCK makes the recovery loop read past the ino[] array and interpret footer or following data as inode numbers.
On a crafted image, mounting an unpatched kernel can drive orphan recovery into f2fs_bug_on() and panic the kernel. Validate entry_count before consuming entries so corrupted checkpoint data fails the mount with -EFSCORRUPTED and requests fsck instead.
Set ERROR_INCONSISTENT_ORPHAN as well, so the corruption reason can be recorded in the superblock s_errors[] field. This gives fsck a persistent hint even though mount-time orphan recovery failure may leave no chance to persist SBI_NEED_FSCK through a checkpoint.
{
"affected": [],
"aliases": [
"CVE-2026-63818"
],
"database_specific": {
"cwe_ids": [],
"github_reviewed": false,
"github_reviewed_at": null,
"nvd_published_at": "2026-07-19T12:16:54Z",
"severity": "HIGH"
},
"details": "In the Linux kernel, the following vulnerability has been resolved:\n\nf2fs: validate orphan inode entry count\n\nf2fs_recover_orphan_inodes() trusts the orphan block entry_count when\nreplaying orphan inodes from the checkpoint pack. A corrupted entry_count\nlarger than F2FS_ORPHANS_PER_BLOCK makes the recovery loop read past the\nino[] array and interpret footer or following data as inode numbers.\n\nOn a crafted image, mounting an unpatched kernel can drive orphan recovery\ninto f2fs_bug_on() and panic the kernel. Validate entry_count before\nconsuming entries so corrupted checkpoint data fails the mount with\n-EFSCORRUPTED and requests fsck instead.\n\nSet ERROR_INCONSISTENT_ORPHAN as well, so the corruption reason can be\nrecorded in the superblock s_errors[] field. This gives fsck a persistent\nhint even though mount-time orphan recovery failure may leave no chance to\npersist SBI_NEED_FSCK through a checkpoint.",
"id": "GHSA-2q7w-rghx-vwh8",
"modified": "2026-07-24T15:32:43Z",
"published": "2026-07-19T12:30:23Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2026-63818"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/210c210c92d78fdf5051bc55c5c69044b1a2150a"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/2e12381d4495dc8b0ff042c6856022b2e359835c"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/550511a2470f6d204fa07b331f048bd2d3c51280"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/846c499a65816d13f1186e3090e825e8bb8bcb8b"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/8aad54746c251f2c2370118df766c0c82e2d2091"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/ad101d15716f5a24d1fa82a849f80430c805a3dd"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d18c81f5d0ecd5796aa47d66d98f2dd54d8d0f70"
},
{
"type": "WEB",
"url": "https://git.kernel.org/stable/c/d2f236196d542ccd8505736e41c3a1d3f0305f6f"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H",
"type": "CVSS_V3"
}
]
}
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