What’s Vulnerable › Vulnerabilities

CVE-2026-98244: btrfs: clear free space tree creation state on rebuild failure

• Severity: unknown
• 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: 2026-10-06 · updated 2026-10-19

Description

In the Linux kernel, the following vulnerability has been resolved: btrfs: clear free space tree creation state on rebuild failure btrfs_rebuild_free_space_tree() sets BTRFS_FS_CREATING_FREE_SPACE_TREE before rebuilding the free space tree. Several error paths return without clearing this flag. The transaction restart failure path can leave the flag set on a live filesystem, causing delayed reference processing to be skipped. Clear it on all free space tree rebuild failure paths. Keep BTRFS_FS_FREE_SPACE_TREE_UNTRUSTED set, since a failed rebuild leaves the free space tree untrusted. Callers must fall back to extent-tree caching.

Affected products

• Linux kernel: 6.14 — fixed in 7.3

How to fix

Upgrade to a fixed version: Linux kernel 7.3. Check the vendor advisory for mitigations.

References

• https://git.kernel.org/stable/c/3565893cc72cdf6b795cf6a33e7ff9605322334d
• https://git.kernel.org/stable/c/a32bedab8ece9d1f90a1476a5b486a1804dc78ba
• https://git.kernel.org/stable/c/b1df2997d0cd2be7bef7b4ab64ccfd1019dedc81

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