Type conversion in Linux kernel - CVE-2026-98475

Vulnerability details

The vulnerability allows a local user to potentially corrupt memory or cause a denial of service through firmware writes to an incorrect memory address.

The vulnerability exists due to missing virtual-to-physical address translation in the s390 channel measurement facility when configuring the measurement block address for extended format channel measurement data. A local user can potentially trigger affected channel measurement processing to cause firmware to store measurement data at an incorrect absolute address, which may corrupt memory or cause a denial of service.

The incorrect addressing occurs on kernels built with CONFIG_RANDOMIZE_IDENTITY_BASE=y.

Affected software

How to mitigate CVE-2026-98475

External References

• https://git.kernel.org/stable/c/748ec2f7f5df9b4fc742546a8bfc8aa5d847353e
• https://git.kernel.org/stable/c/7f78226eb743b362f52b212d7763801642539d1c
• https://git.kernel.org/stable/c/b11f369be31ea11c746833e4d3ad51dcd6b5fa2b
• https://git.kernel.org/stable/c/f4d04425e66af2ecee9d1a49ae0484436f3c2fd1

Related Security Bulletins

• Type conversion in Linux kernel s390 cio driver
• Ubuntu update for linux-oem-7.0
• Ubuntu update for linux, linux-aws, linux-gcp and more