Incomplete cleanup in Linux kernel - CVE-2026-98244

Vulnerability identifier: #VU153775

CSH Severity: Low

CVSS v4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N]

CVE-ID: CVE-2026-98244

CWE-ID: CWE-459

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to cause delayed reference processing to be skipped.

The vulnerability exists due to incomplete cleanup of the free space tree creation state in btrfs_rebuild_free_space_tree() when rebuilding the free space tree fails. A local user can trigger a free space tree rebuild that encounters an error to cause delayed reference processing to be skipped.

The transaction restart failure path can leave the affected filesystem live.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-aws (Ubuntu package)
linux-gcp (Ubuntu package)
linux-oracle (Ubuntu package)
linux-ibm (Ubuntu package)
linux-hwe-7.0 (Ubuntu package)
linux-oem-7.0 (Ubuntu package)

Install security update from vendor's repository.

Linux kernel - update to 7.0 rc3
linux (Ubuntu package) - update to 7.0.0-42.42
linux-aws (Ubuntu package) - update to 7.0.0-1016.17
linux-gcp (Ubuntu package) - update to 7.0.0-1016.18
linux-oracle (Ubuntu package) - update to 7.0.0-1015.16
linux-ibm (Ubuntu package) - update to 7.0.0-1017.17
linux-hwe-7.0 (Ubuntu package) - update to 7.0.0-42.42~24.04.1
linux-oem-7.0 (Ubuntu package) - update to 7.0.0-1017.17

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

• Incomplete cleanup in Linux kernel btrfs
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more