CVE-2025-38382: btrfs: fix iteration of extrefs during log replay

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-25 · updated 2026-07-30
Weakness: CWE-908

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix iteration of extrefs during log replay At __inode_add_ref() when processing extrefs, if we jump into the next label we have an undefined value of victim_name.len, since we haven't initialized it before we did the goto. This results in an invalid memory access in the next iteration of the loop since victim_name.len was not initialized to the length of the name of the current extref. Fix this by initializing victim_name.len with the current extref's name length.

Affected products

Debian Linux: 11.0
Linux kernel: from 6.1.57 before 6.1.144; from 6.2 before 6.6.97; from 6.7 before 6.12.37; from 6.13 before 6.15.6; 6.16-rc1, 6.16-rc2, 6.16-rc3, 6.16-rc4 — fixed in 6.1.144, 6.12.37, 6.15.6, 6.6.97

How to fix

Upgrade to a fixed version: Linux kernel 6.1.144, 6.12.37, 6.15.6, 6.6.97. Check the vendor advisory for mitigations.

References

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