CVE-2026-43228: hfs: Replace BUG_ON with error handling for CNID count checks

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: 2026-05-06 · updated 2026-10-15
Weakness: CWE-617

Description

In the Linux kernel, the following vulnerability has been resolved: hfs: Replace BUG_ON with error handling for CNID count checks In a06ec283e125 next_id, folder_count, and file_count in the super block info were expanded to 64 bits, and BUG_ONs were added to detect overflow. This triggered an error reported by syzbot: if the MDB is corrupted, the BUG_ON is triggered. This patch replaces this mechanism with proper error handling and resolves the syzbot reported bug. Singed-off-by: Jori Koolstra <jkoolstra@xs4all.nl>

Affected products

Linux kernel: from 6.18 before 6.19.6 — fixed in 6.19.6

How to fix

Upgrade to a fixed version: Linux kernel 6.19.6. Check the vendor advisory for mitigations.

References

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