CVE-2025-68761: hfs: fix potential use after free in hfs_correct_next_unused_CNID()

Severity: high (CVSS 7.8 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: 2026-01-05 · updated 2026-10-14

Description

In the Linux kernel, the following vulnerability has been resolved: hfs: fix potential use after free in hfs_correct_next_unused_CNID() This code calls hfs_bnode_put(node) which drops the refcount and then dreferences "node" on the next line. It's only safe to use "node" when we're holding a reference so flip these two lines around.

Affected products

Linux kernel: 6.18 — fixed in 6.19

How to fix

Upgrade to a fixed version: Linux kernel 6.19. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/40a1e0142096dd7dd6cb5373841222b528698588
https://git.kernel.org/stable/c/c105e76bb17cf4b55fe89c6ad4f6a0e3972b5b08

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