Bug 2373357 (CVE-2025-38074)

Summary: CVE-2025-38074 kernel: vhost-scsi: protect vq->log_used with vq->mutex
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: dfreiber, drow, jburrell, vkumar
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Description OSIDB Bzimport 2025-06-18 10:03:21 UTC
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.

Comment 1 Avinash Hanwate 2025-06-20 18:57:16 UTC
Upstream advisory:
https://lore.kernel.org/linux-cve-announce/2025061839-CVE-2025-38074-dc14@gregkh/T