Improper error handling in Linux kernel - CVE-2025-21984

Vulnerability identifier: #VU106837

CSH Severity: Low

CVSS v4: 6.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2025-21984

CWE-ID: CWE-388

Exploitation vector: Local access

Exploit availability: No public exploit available

The vulnerability allows a local user to perform a denial of service (DoS) attack.

The vulnerability exists due to improper error handling within the validate_dst_vma(), move_swap_pte(), move_pages_pte() and pte_to_swp_entry() functions in mm/userfaultfd.c. A local user can perform a denial of service (DoS) attack.

Linux kernel
Ubuntu
linux (Ubuntu package)
linux-lowlatency (Ubuntu package)
linux-azure (Ubuntu package)
linux-oem-6.11 (Ubuntu package)

Install update from vendor's website.

Linux kernel - addressed in versions 6.12.20, 6.13.8, 6.14
linux (Ubuntu package) - addressed in versions 6.11.0-28.28, 6.11.0-28.28~24.04.1, 6.11.0-1011.11, 6.11.0-1014.14, 6.11.0-1015.16, 6.11.0-1016.16, 6.11.0-1016.16~24.04.1, 6.11.0-1017.18
linux-lowlatency (Ubuntu package) - addressed in versions 6.11.0-1015.16, 6.11.0-1015.16~24.04.2
linux-azure (Ubuntu package) - addressed in versions 6.11.0-1018.18, 6.11.0-1018.18~24.04.1
linux-oem-6.11 (Ubuntu package) - update to 6.11.0-1024.24

• https://git.kernel.org/stable/c/4e9507246298fd6f1ca7bb42ef01a6e34fb93684
• https://git.kernel.org/stable/c/b1e11bd86c0943bb7624efebdc384340a50ad683
• https://git.kernel.org/stable/c/c50f8e6053b0503375c2975bf47f182445aebb4c
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.20
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.13.8
• https://mirrors.edge.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.14

• Improper error handling in Linux kernel mm
• Ubuntu update for linux
• Ubuntu update for linux-oem-6.11
• Ubuntu update for linux-lowlatency
• Ubuntu update for linux-azure