CVE-2026-46078: erofs: fix the out-of-bounds nameoff handling for trailing dirents

Severity: high (CVSS 7.1 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.1% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-05-27 · updated 2026-10-19
Weakness: CWE-125

Description

In the Linux kernel, the following vulnerability has been resolved: erofs: fix the out-of-bounds nameoff handling for trailing dirents Currently we already have boundary-checks for nameoffs, but the trailing dirents are special since the namelens are calculated with strnlen() with unchecked nameoffs. If a crafted EROFS has a trailing dirent with nameoff >= maxsize, maxsize - nameoff can underflow, causing strnlen() to read past the directory block. nameoff0 should also be verified to be a multiple of `sizeof(struct erofs_dirent)` as well [1]. [1] https://sashiko.dev/#/patchset/20260416063511.3173774-1-hsiangkao%40linux.alibaba.com

Affected products

Linux kernel: from 4.19 before 5.10.259; from 5.11 before 5.15.210; from 5.16 before 6.1.175; from 6.2 before 6.6.140; from 6.7 before 6.12.86; from 6.13 before 6.18.27 — fixed in 5.10.259, 5.15.210, 6.1.175, 6.12.86, 6.18.27, 6.6.140

How to fix

Upgrade to a fixed version: Linux kernel 5.10.259, 5.15.210, 6.1.175, 6.12.86. Check the vendor advisory for mitigations.

References

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