CVE-2025-39815: RISC-V: KVM: fix stack overrun when loading vlenb
In the Linux kernel, the following vulnerability has been resolved:
RISC-V: KVM: fix stack overrun when loading vlenb
The userspace load can put up to 2048 bits into an xlen bit stack buffer. We want only xlen bits, so check the size beforehand.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.13-1 - Compensating control
In RISC-V KVM, validate the userspace load size before loading vlenb into the stack buffer, accepting only xlen bits to prevent up to 2048 bits from overflowing the xlen-bit buffer.
Event History
Frequently Asked Questions
What is the severity of CVE-2025-39815?
CVE-2025-39815 has been rated as a high severity vulnerability due to the potential for stack overflows in the Linux kernel.
How do I fix CVE-2025-39815?
To fix CVE-2025-39815, users should update their Linux kernel to the latest patched version that addresses this vulnerability.
What are the potential impacts of CVE-2025-39815?
The potential impacts of CVE-2025-39815 include system crashes or arbitrary code execution resulting from a stack overrun.
Which versions of Linux Kernel are affected by CVE-2025-39815?
CVE-2025-39815 affects multiple versions of the Linux Kernel; specifically, any version that allows the stack buffer to be overloaded.
Is CVE-2025-39815 publicly known?
Yes, CVE-2025-39815 is a publicly known vulnerability, and it has been documented in various security advisories.