SB20260720155 - Use of Uninitialized Variable in Linux kernel riscv kernel

Description

This security bulletin contains information about 1 vulnerability.

1) Use of Uninitialized Variable (CVE-ID: CVE-2026-64082)

CWE-ID: CWE-457 - Use of Uninitialized Variable

CVSSv4: 4.8 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N]

The vulnerability allows a local user to corrupt register state and disclose kernel stack contents.

The vulnerability exists due to use of uninitialized stack data in compat_riscv_gpr_set() and compat_restore_sigcontext() when handling failed user memory copies. A local user can provide crafted user-supplied register or signal context data that triggers a copy failure to corrupt register state and disclose kernel stack contents.

The issue affects the RISC-V compatibility signal and ptrace handling paths.

Remediation

Install update from vendor's website.

References

• https://git.kernel.org/stable/c/6ebcbb53fc9bc30843054ed99fd60b8e542628f4
• https://git.kernel.org/stable/c/9e020156833f1ad0d425a1e3d85b65639f1c1c50