What’s Vulnerable › Vulnerabilities

CVE-2025-39800: btrfs: abort transaction on unexpected eb generation at btrfs_copy_root()

• 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: 2025-09-15 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: abort transaction on unexpected eb generation at btrfs_copy_root() If we find an unexpected generation for the extent buffer we are cloning at btrfs_copy_root(), we just WARN_ON() and don't error out and abort the transaction, meaning we allow to persist metadata with an unexpected generation. Instead of warning only, abort the transaction and return -EUCLEAN.

Affected products

• Debian Linux: 11.0
• Linux kernel: from 2.6.29 before 6.1.149; from 6.2 before 6.6.103; from 6.7 before 6.12.44; from 6.13 before 6.16.4 — fixed in 6.1.149, 6.12.44, 6.16.4, 6.6.103

How to fix

Upgrade to a fixed version: Linux kernel 6.1.149, 6.12.44, 6.16.4, 6.6.103. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/33e8f24b52d2796b8cfb28c19a1a7dd6476323a8
• https://git.kernel.org/stable/c/4290e34fb87ae556b12c216efd0ae91583446b7a
• https://git.kernel.org/stable/c/4734255ef39b416864139dcda96a387fe5f33a6a
• https://git.kernel.org/stable/c/da2124719f386b6e5d4d4b1a2e67c440e4d5892f
• https://git.kernel.org/stable/c/f4f5bd9251a4cbe55aaa05725c6c3c32ad1f74b3
• https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html
• https://cert-portal.siemens.com/productcert/html/ssa-032379.html

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