CVE-2026-80809

/// Technical description

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

ocfs2: fix missing metadata reservation for large xattrs

[BUG]

lsetxattr() panics the kernel when setting a large xattr value on a

fragmented filesystem where the file already has an external xattr

block.

[CAUSE]

ocfs2_calc_xattr_set_need() never reserves metadata blocks for a new

xattr value's extent tree when the file already has an external xattr

block. The not_found path leaves meta_add at zero, so meta_ac is NULL

when ocfs2_xattr_extend_allocation() runs.

A new value root has room for a single extent record. On a fragmented

filesystem, the allocator cannot satisfy the xattr value in one

contiguous run, so each non-contiguous run requires its own extent

record. When the value root's extent list is full and meta_ac is NULL,

ocfs2_add_clusters_in_btree() returns RESTART_META, and

ocfs2_xattr_extend_allocation() hits BUG_ON(why == RESTART_META).

[FIX]

The case where no xattr block exists yet already calls

ocfs2_e

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References