GHSA-3qx8-rv27-j6gp Undefined behaviour in `kvm_ioctls::ioctls::vm::VmFd::create_device`
Undefined behavior in KVM device creation causes incorrect file descriptor handling, potentially leading to logic errors or crashes in virtualization applications.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Not stated
- Victim action needed
- Not needed
- Fix
- Available
What is GHSA-3qx8-rv27-j6gp?
GHSA-3qx8-rv27-j6gp is a vulnerability in kvm-ioctls, published on 5 Dec 2024.
Official description
An issue was identified in the VmFd::create_device function, leading to undefined behavior and miscompilations on rustc 1.82.0 and newer due to the function's violation of Rust's pointer safety rules.
The function downcasted a mutable reference to its struct kvm_create_device argument to an immutable pointer, and then proceeded to pass this pointer to a mutating system call. Rustc 1.82.0 and newer elides subsequent reads of this structure's fields, meaning code will not see the value written by the kernel into the fd member. Instead, the code will observe the value that this field was initialized to prior to calling VmFd::create_device (usually, 0).
The issue started in kvm-ioctls 0.1.0 and was fixed in 0.19.1 by correctly using a mutable pointer.
Which versions are affected by GHSA-3qx8-rv27-j6gp?
3 open source packages ship an affected version, including kvm-ioctls.
| Package | Affected | Fixed in |
|---|---|---|
kvm-ioctls crates.io | All versions | 0.19.1 |
kvm-ioctls crates.io | All versions | 0.19.1 |
kvm-ioctls crates.io | From 0.0.0-0 | 0.19.1 |
How do I fix GHSA-3qx8-rv27-j6gp?
Upgrade kvm-ioctls to 0.19.1 or later.
Is GHSA-3qx8-rv27-j6gp being exploited?
There is no known exploitation of GHSA-3qx8-rv27-j6gp in the wild and no public exploit code.
Sources
Also known as RUSTSEC-2024-0428.