CVE-2026-64082
Published: July 22, 2026Last modified: July 22, 2026
Description
In the Linux kernel, the following vulnerability has been resolved: riscv: Fix register corruption from uninitialized cregs on error compat_riscv_gpr_set() calls cregs_to_regs() unconditionally, even when user_regset_copyin() fails. Since cregs is an uninitialized stack variable, a copyin failure causes uninitialized stack data to be written into the target task's pt_regs, corrupting its register state and potentially leaking kernel stack contents. compat_restore_sigcontext() has the same issue: it calls cregs_to_regs() even when __copy_from_user() fails, leading to the same corruption of the signal-returning task's register state on error. Only call cregs_to_regs() when the user copy succeeds.
Severity score breakdown
| Parameter | Value |
|---|---|
| Base score | 7.8 |
| Attack Vector | LOCAL |
| Attack complexity | LOW |
| Privileges required | LOW |
| User interaction | NONE |
| Scope | UNCHANGED |
| Confidentiality | HIGH |
| Integrity impact | HIGH |
| Availability impact | HIGH |
| Vector | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H |
Status
| Product | Release | Package | Status |
|---|---|---|---|
| Alpaquita Linux | 23 LTS | linux-lts | Vulnerable (6.1.177-r0) |
| 25 LTS | linux-lts | Vulnerable (6.12.95-r0) | |
| Stream | linux-lts | Vulnerable (6.18.38-r0) |
References
- https://git.kernel.org/stable/c/0599aa23734c48de9bce36d043a9ec90c23945a1
- https://git.kernel.org/stable/c/2a7d1daf2674fe7d5b1cc99a4e3b5f0f72d5958f
- https://git.kernel.org/stable/c/66dedb6028c3df6c6a3372dd935b823917e150d5
- https://git.kernel.org/stable/c/6ebcbb53fc9bc30843054ed99fd60b8e542628f4
- https://git.kernel.org/stable/c/9e020156833f1ad0d425a1e3d85b65639f1c1c50
- https://git.kernel.org/stable/c/f2d88b0d7aebfa4643fc58bbae57210c6daff9c6