CVE-2025-38435: riscv: vector: Fix context save/restore with xtheadvector

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2025-07-25 · updated 2026-07-30

Description

In the Linux kernel, the following vulnerability has been resolved: riscv: vector: Fix context save/restore with xtheadvector Previously only v0-v7 were correctly saved/restored, and the context of v8-v31 are damanged. Correctly save/restore v8-v31 to avoid breaking userspace.

Affected products

Linux kernel: from 6.14 before 6.15.5; 6.16-rc1, 6.16-rc2, 6.16-rc3 — fixed in 6.15.5

How to fix

Upgrade to a fixed version: Linux kernel 6.15.5. Check the vendor advisory for mitigations.

References

https://git.kernel.org/stable/c/4262bd0d9cc704ea1365ac00afc1272400c2cbef
https://git.kernel.org/stable/c/dd5ceea8d50e9e108a10d1e0d89fa2c9ff442ca2

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