Improper handling of exceptional conditions in Linux kernel - CVE-2026-64369

Vulnerability details

The vulnerability allows a local user to cause a denial of service.

The vulnerability exists due to improper exception handling in load_unaligned_zeropad() and the s390 secure storage access exception handler when reading unaligned data across page boundaries involving donated secure-execution pages. A local user can trigger the vulnerable kernel access pattern to cause a denial of service.

The issue can result in an endless exception loop when the second page access raises an exception for pages donated to the Ultravisor for secure execution purposes.

Affected software

How to mitigate CVE-2026-64369

External References

• https://git.kernel.org/stable/c/37540b8c287fc817bdbd0c62bb75ad6eab0e5d03
• https://git.kernel.org/stable/c/be79d285bea70d0edd5015bd487311bfa8cbebc9
• https://git.kernel.org/stable/c/c94806905e02cc8e17a69c822d93c41743b7ffc5
• https://git.kernel.org/stable/c/c9e0f1517631ac08987f8385817119bccf2f1f12

Related Security Bulletins

• Improper handling of exceptional conditions in Linux kernel s390 mm
• Debian update for linux