SB2026092829 - Incorrect calculation in Linux kernel ext4

Description

This security bulletin contains information about 1 vulnerability.

1) Incorrect calculation (CVE-ID: CVE-2026-100073)

CWE-ID: CWE-682 - Incorrect Calculation

CVSSv4: 2 [CVSS:4.0/AV:L/AC:L/AT:P/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N]

The vulnerability allows a local user to cause a transaction overflow.

The vulnerability exists due to incorrect transaction credit calculation in the ext4 writeback extent-conversion logic when performing ext4 writeback that requires extent conversion. A local user can trigger ext4 writeback requiring extent conversion to cause a transaction overflow.

This may occur when sparse folio dirtying requires a large unwritten extent to be split into multiple written extents and new extent-tree nodes to be allocated.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/46e8e31771f4f1c5e1cdec37a889a6730e42e9f1
• https://git.kernel.org/stable/c/a22464c5df5827e884a5a7d3d8fb03870e5bb6c8