# CVE-2026-46169: hfsplus: fix uninit-value by validating catalog record size

CVE-2026-46169 is fixed in linux on 1 platform, first by DEBIAN-CVE-2026-46169, released June 24, 2026. It is not reported as exploited. Patch Radar priority: Routine.

- Web page: https://patchblox.com/security/cve/CVE-2026-46169
- Priority: Routine
- CVSS: 5.5 (Low)
- EPSS: 0.0013
- CISA KEV: not listed
- Exploited (vendor report): no
- Publicly disclosed: no
- Published: May 28, 2026
- Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-46169

## Description

In the Linux kernel, the following vulnerability has been resolved:  hfsplus: fix uninit-value by validating catalog record size  Syzbot reported a KMSAN uninit-value issue in hfsplus_strcasecmp(). The root cause is that hfs_brec_read() doesn't validate that the on-disk record size matches the expected size for the record type being read.  When mounting a corrupted filesystem, hfs_brec_read() may read less data than expected. For example, when reading a catalog thread record, the debug output showed:    HFSPLUS_BREC_READ: rec_len=520, fd->entrylength=26   HFSPLUS_BREC_READ: WARNING - entrylength (26) < rec_len (520) - PARTIAL READ!  hfs_brec_read() only validates that entrylength is not greater than the buffer size, but doesn't check if it's less than expected. It successfully reads 26 bytes into a 520-byte structure and returns success, leaving 494 bytes uninitialized.  This uninitialized data in tmp.thread.nodeName then gets copied by hfsplus_cat_build_key_uni() and used by hfsplus_strcasecmp(), triggering the KMSAN warning when the uninitialized bytes are used as array indices in case_fold().  Fix by introducing hfsplus_brec_read_cat() wrapper that: 1. Calls hfs_brec_read() to read the data 2. Validates the record size based on the type field:    - Fixed size for folder and file records    - Variable size for thread records (depends on string length) 3. Returns -EIO if size doesn't match expected  For thread records, check against HFSPLUS_MIN_THREAD_SZ before reading nodeName.length to avoid reading uninitialized data at call sites that don't zero-initialize the entry structure.  Also initialize the tmp variable in hfsplus_find_cat() as defensive programming to ensure no uninitialized data even if validation is bypassed.

## Where it's fixed

| Platform | Product | Fixed in | Fix | Released |
|---|---|---|---|---|
| Linux | linux Debian 12.15 (bookworm) | 6.1.176-1 | [DEBIAN-CVE-2026-46169](https://patchblox.com/security/data/fix/linux/debian-cve-2026-46169.md) | Jun 24, 2026 |
| Linux | linux Debian 13.5 (trixie) | 6.12.88-1 | [DEBIAN-CVE-2026-46169](https://patchblox.com/security/data/fix/linux/debian-cve-2026-46169.md) | Jun 24, 2026 |
| Linux | linux Debian 14 | 7.0.7-1 | [DEBIAN-CVE-2026-46169](https://patchblox.com/security/data/fix/linux/debian-cve-2026-46169.md) | Jun 24, 2026 |

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Data as of 2026-11-08T19:12:23Z UTC. Source: Patchblox Patch Radar (https://patchblox.com/security/patch-radar). Patchblox finds out-of-date software on Windows, macOS and Linux and updates it through release rings: https://patchblox.com/demo

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