CVE-2026-64360: hfs/hfsplus: zero-initialize buffer in hfs_bnode_read
In the Linux kernel, the following vulnerability has been resolved:
hfs/hfsplus: zero-initialize buffer in hfsbnoderead
hfsbnoderead() can return early without writing to the output buffer when isbnodeoffsetvalid() fails or when checkandcorrectrequested length() corrects the length to zero. Callers such as hfsbnoderead u16() and hfsbnodereadu8() pass stack-allocated buffers and use the result unconditionally, leading to KMSAN uninit-value reports.
Rather than initializing at each individual call site, zero the buffer at the start of hfsbnoderead() before any validation checks. This ensures all callers in both hfs and hfsplus get a deterministic zero value regardless of which early-return path is taken.
Affected Software
Event History
Frequently Asked Questions
What level of access does an attacker need?
The CVSS vector indicates local attack access and low privileges are required. No user interaction is required.
Which filesystem code paths are covered by the fix?
The change applies to callers in both the hfs and hfsplus code. It ensures early returns from hfs_bnode_read() leave callers with a deterministic zero value rather than uninitialized stack data.
What is the primary security impact?
The reported impact is availability only, rated High in the CVSS vector. The vector reports no confidentiality or integrity impact.