CVE-2026-64146: erofs: fix metabuf leak in inode xattr initialization

Severity: medium (CVSS 5.5 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: 2026-07-19 · updated 2026-10-30
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: erofs: fix metabuf leak in inode xattr initialization commit bb88e8da0025 ("erofs: use meta buffers for xattr operations") converted xattr operations to use on-stack erofs_buf instances. erofs_init_inode_xattrs() uses such a metabuf while reading the inline xattr header and shared xattr id array. Some error paths after erofs_read_metabuf() leave through out_unlock without dropping the metabuf, so the folio reference can leak. Consolidate the cleanup at out_unlock. erofs_put_metabuf() is a no-op if no folio has been acquired, and this keeps all paths after taking EROFS_I_BL_XATTR_BIT covered by a single cleanup site.

Affected products

Linux kernel: from 5.17 before 7.0.11; 7.1-rc1, 7.1-rc2, 7.1-rc3, 7.1-rc4 — fixed in 7.0.11
Linux: 5.17 — fixed in 7.1

How to fix

Upgrade to a fixed version: Linux kernel 7.0.11; Linux 7.1. Check the vendor advisory for mitigations.

References

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