Linux hwe edge: In the Linux kernel, the following vulnerability has been resolved: hfsplus: Add a sanity check for btree node size Syzbot reported an uninit-value… (CVE-2026-80656)

The Linux kernel's HFS+ filesystem driver had an uninitialized value vulnerability reported by Syzbot. During the mounting of a corrupted HFS+ image, a corrupted node_size value of 1 led to an excessively large offset passed to hfs_bnode_read_u16(), causing the function to fail to return a valid value and triggering the bug. The vulnerability was addressed by adding a sanity check to ensure the B-tree node size conforms to the specification requiring it to be a power of two between 512 and 32,768 bytes.

This vulnerability could allow a local attacker with the ability to mount a crafted corrupted HFS+ filesystem image to cause memory corruption, potentially leading to denial of service or escalation of privileges. The CVSS score of 7.8 indicates a high impact on confidentiality, integrity, and availability, but the attack vector requires local access and low privileges.

A fix has been implemented in the Linux kernel to add a sanity check for the B-tree node size in the HFS+ filesystem driver. Users should update their Linux kernel to a version that includes this patch. Since this is a kernel-level fix, applying the official kernel update from the vendor or distribution is the recommended remediation. No additional mitigation steps are indicated.