CVE Catalog

CVE-2026-93798

HighCVSS 7.8
Published: Updated: Translated: NVD NIST

Exploitation Probability (EPSS)

Low risk
0.13%

2th percentile - higher than 2% of all known CVEs

Summary

In the Linux kernel btrfs filesystem, merge_reloc_roots() has an issue with reloc root cleanup: when a root has zero references, the reloc_root pointer is reset without memory barriers, and the BTRFS_ROOT_DEAD_RELOC_TREE flag is cleared incorrectly. The fix uses clear_reloc_root() to ensure proper synchronization.

Risk Assessment

This could lead to filesystem state inconsistencies, potentially causing data corruption or system crashes.

Recommendation

Install the updated Linux kernel with the btrfs fix.

Other vulnerabilities in Linux kernel

See all
Original NVD description (English source)

In the Linux kernel, the following vulnerability has been resolved: btrfs: fix reloc root cleanup in merge_reloc_roots() If the root we got has zero root refs in its root item, we are resetting the root's ->reloc_root without using barriers like we do everywhere else. Sashiko complained about this while reviewing another patch, and it's correct (see the Link tag below). Also, we should not clear BTRFS_ROOT_DEAD_RELOC_TREE from the root unless the root points to the reloc root we have. Fix this by using clear_reloc_root(), which issues the memory barrier after setting the root's ->reloc_root to NULL and before clearing the bit BTRFS_ROOT_DEAD_RELOC_TREE from the root.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS