CVE-2026-98745

/// Technical description

In the Linux kernel, the following vulnerability has been resolved:

arm64/fpsimd: signal: Forbid non-streaming SVE payload on SME-only systems

When system_supports_sme() is true but system_supports_sve() is false,

restoring a specifically crafted SVE signal context can result in the

task erroneously having non-streaming SVE state. Subsequent attempts to

manipulate the task's FPSIMD/SVE/SME state can result in a variety of

problems, including fatal EL1 UNDEFs.

In such configurations, the kernel always creates an SVE signal context

when delivering a signal, and this can only be in one of two states:

(1) SVE_SIG_FLAG_SM is set, and an SVE payload is present containing

streaming mode SVE state. The recorded VL is the task's live

streaming VL.

(2) SVE_SIG_FLAG_SM is clear, and an SVE payload is not present. The

FPSIMD context contains the non-streaming mode FPSIMD state. The

recorded VL is 0.

Currently restore_sve_fpsimd_context() correctly rejects cases where

SVE_SIG_

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References