PT-2026-61134 · Linux · Linux

CVE-2026-63818 · Published 2026-07-19 · Updated 2026-07-19

NVD

CVSS v3.1

8.4

High

Base vector

AV:L/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

In 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.

Fix

Related Identifiers

CVE-2026-63818

Affected Products

Linux

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2026-63818 · Security Note
• https://git.kernel.org/stable/c/846c499a65816d13f1186e3090e825e8bb8bcb8b · Note
• https://git.kernel.org/stable/c/8aad54746c251f2c2370118df766c0c82e2d2091 · Note
• https://git.kernel.org/stable/c/550511a2470f6d204fa07b331f048bd2d3c51280 · Note
• https://git.kernel.org/stable/c/2e12381d4495dc8b0ff042c6856022b2e359835c · Note