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->log_base when vq->log_used is already set to false.

vhost-thread                       QEMU-thread

vhost_scsi_complete_cmd_work() -> vhost_add_used() -> vhost_add_used_n() if (unlikely(vq->log_used)) QEMU disables vq->log_used via VHOST_SET_VRING_ADDR. mutex_lock(&vq->mutex); vq->log_used = 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.

This vulnerability has no security impact on Red Hat Enterprise Linux or other Red Hat products because the affected vhost-scsi driver is not enabled in supported kernels. The flaw stems from improper locking during vring logging updates, which could allow asynchronous I/O completion routines to write into deallocated hypervisor memory space. Because Red Hat kernel builds do not compile or ship this virtualization driver, supported configurations are not susceptible to this condition.