CVE-2025-38074

In the Linux kernel, the following vulnerability has been resolved:

vhost-scsi: protect vq->log_used with vq->mutex

The vhost-scsi completion path may access vq->logbase when vq->logused is already set to false.

vhost-thread                       QEMU-thread

vhostscsicompletecmdwork() -> vhostaddused() -> vhostaddusedn() if (unlikely(vq->logused)) QEMU disables vq->logused via VHOSTSETVRINGADDR. mutexlock(&vq->mutex); vq->logused = false now! mutex_unlock(&vq->mutex);

                  QEMU gfree(vq->log_base)
    log_used()
    -> log_write(vq->log_base)

Assuming the VMM is QEMU. The vq->log_base is from QEMU userpace and can be reclaimed via gfree(). As a result, this causes invalid memory writes to QEMU userspace.

The control queue path has the same issue.