On 7/10/2025 9:41 PM, Greg KH wrote:
On Wed, Jul 02, 2025 at 08:29:45AM +0000, Xinyu Zheng wrote:
From: Dongli Zhang <dongli.zh...@oracle.com>
[ Upstream commit f591cf9fce724e5075cc67488c43c6e39e8cbe27 ]
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.
CVE-2025-38074
This is not needed.
Cc: sta...@vger.kernel.org#5.10.x
What about 5.15.y and 6.1.y? We can't take a patch just for 5.10 as
that would cause regressions, right?
Please provide all relevant backports and I will be glad to queue them
up then. I'll drop this from my queue for now, thanks.
greg k-h
Sorry for forgetting the 5.15.y and 6.1.y patches. I will resend it as
soon as possible. Thanks for pointing out my patch format error.
Xinyu Zheng
