From: Dongli Zhang <dongli.zhang@oracle.com> stable inclusion from stable-v6.6.93 commit ca85c2d0db5f8309832be45858b960d933c2131c category: bugfix bugzilla: https://gitee.com/src-openeuler/kernel/issues/ICGAEC CVE: CVE-2025-38074 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ 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. Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com> Acked-by: Jason Wang <jasowang@redhat.com> Reviewed-by: Mike Christie <michael.christie@oracle.com> Message-Id: <20250403063028.16045-2-dongli.zhang@oracle.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> --- drivers/vhost/scsi.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 99813232c25e..d4e60a6ed214 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -560,6 +560,9 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) int ret; llnode = llist_del_all(&svq->completion_list); + + mutex_lock(&svq->vq.mutex); + llist_for_each_entry_safe(cmd, t, llnode, tvc_completion_list) { se_cmd = &cmd->tvc_se_cmd; @@ -593,6 +596,8 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) vhost_scsi_release_cmd_res(se_cmd); } + mutex_unlock(&svq->vq.mutex); + if (signal) vhost_signal(&svq->vs->dev, &svq->vq); } @@ -1301,8 +1306,11 @@ static void vhost_scsi_tmf_resp_work(struct vhost_work *work) resp_code = VIRTIO_SCSI_S_FUNCTION_REJECTED; } + mutex_lock(&tmf->svq->vq.mutex); vhost_scsi_send_tmf_resp(tmf->vhost, &tmf->svq->vq, tmf->in_iovs, tmf->vq_desc, &tmf->resp_iov, resp_code); + mutex_unlock(&tmf->svq->vq.mutex); + vhost_scsi_release_tmf_res(tmf); } -- 2.34.1