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From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com
Cc: virtualization@lists.linux-foundation.org,
	linux-kernel@vger.kernel.org, xieyongji@bytedance.com,
	stefanha@redhat.com, file@sect.tu-berlin.de,
	ashish.kalra@amd.com, martin.radev@aisec.fraunhofer.de,
	konrad.wilk@oracle.com, kvm@vger.kernel.org
Subject: [RFC PATCH 4/7] virtio_ring: secure handling of mapping errors
Date: Wed, 21 Apr 2021 11:21:14 +0800	[thread overview]
Message-ID: <20210421032117.5177-5-jasowang@redhat.com> (raw)
In-Reply-To: <20210421032117.5177-1-jasowang@redhat.com>

We should not depend on the DMA address, length and flag of descriptor
table since they could be wrote with arbitrary value by the device. So
this patch switches to use the stored one in desc_extra.

Note that the indirect descriptors are fine since they are read-only
streaming mappings.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/virtio/virtio_ring.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 0cdd965dba58..5509c2643fb1 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1213,13 +1213,16 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
 unmap_release:
 	err_idx = i;
 	i = head;
+	curr = vq->free_head;
 
 	vq->packed.avail_used_flags = avail_used_flags;
 
 	for (n = 0; n < total_sg; n++) {
 		if (i == err_idx)
 			break;
-		vring_unmap_desc_packed(vq, &desc[i]);
+		vring_unmap_state_packed(vq,
+					 &vq->packed.desc_extra[curr]);
+		curr = vq->packed.desc_extra[curr].next;
 		i++;
 		if (i >= vq->packed.vring.num)
 			i = 0;
-- 
2.25.1


WARNING: multiple messages have this Message-ID (diff)
From: Jason Wang <jasowang@redhat.com>
To: mst@redhat.com, jasowang@redhat.com
Cc: ashish.kalra@amd.com, file@sect.tu-berlin.de,
	martin.radev@aisec.fraunhofer.de, kvm@vger.kernel.org,
	konrad.wilk@oracle.com, linux-kernel@vger.kernel.org,
	virtualization@lists.linux-foundation.org,
	xieyongji@bytedance.com, stefanha@redhat.com
Subject: [RFC PATCH 4/7] virtio_ring: secure handling of mapping errors
Date: Wed, 21 Apr 2021 11:21:14 +0800	[thread overview]
Message-ID: <20210421032117.5177-5-jasowang@redhat.com> (raw)
In-Reply-To: <20210421032117.5177-1-jasowang@redhat.com>

We should not depend on the DMA address, length and flag of descriptor
table since they could be wrote with arbitrary value by the device. So
this patch switches to use the stored one in desc_extra.

Note that the indirect descriptors are fine since they are read-only
streaming mappings.

Signed-off-by: Jason Wang <jasowang@redhat.com>
---
 drivers/virtio/virtio_ring.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 0cdd965dba58..5509c2643fb1 100644
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1213,13 +1213,16 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
 unmap_release:
 	err_idx = i;
 	i = head;
+	curr = vq->free_head;
 
 	vq->packed.avail_used_flags = avail_used_flags;
 
 	for (n = 0; n < total_sg; n++) {
 		if (i == err_idx)
 			break;
-		vring_unmap_desc_packed(vq, &desc[i]);
+		vring_unmap_state_packed(vq,
+					 &vq->packed.desc_extra[curr]);
+		curr = vq->packed.desc_extra[curr].next;
 		i++;
 		if (i >= vq->packed.vring.num)
 			i = 0;
-- 
2.25.1

_______________________________________________
Virtualization mailing list
Virtualization@lists.linux-foundation.org
https://lists.linuxfoundation.org/mailman/listinfo/virtualization

  parent reply	other threads:[~2021-04-21  3:22 UTC|newest]

Thread overview: 32+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-04-21  3:21 [RFC PATCH 0/7] Untrusted device support for virtio Jason Wang
2021-04-21  3:21 ` Jason Wang
2021-04-21  3:21 ` [RFC PATCH 1/7] virtio-ring: maintain next in extra state for packed virtqueue Jason Wang
2021-04-21  3:21   ` Jason Wang
2021-04-21  3:21 ` [RFC PATCH 2/7] virtio_ring: rename vring_desc_extra_packed Jason Wang
2021-04-21  3:21   ` Jason Wang
2021-04-21  3:21 ` [RFC PATCH 3/7] virtio-ring: factor out desc_extra allocation Jason Wang
2021-04-21  3:21   ` Jason Wang
2021-04-21  3:21 ` Jason Wang [this message]
2021-04-21  3:21   ` [RFC PATCH 4/7] virtio_ring: secure handling of mapping errors Jason Wang
2021-04-21  3:21 ` [RFC PATCH 5/7] virtio_ring: introduce virtqueue_desc_add_split() Jason Wang
2021-04-21  3:21   ` Jason Wang
2021-04-21  3:21 ` [RFC PATCH 6/7] virtio: use err label in __vring_new_virtqueue() Jason Wang
2021-04-21  3:21   ` Jason Wang
2021-04-21  3:21 ` [RFC PATCH 7/7] virtio-ring: store DMA metadata in desc_extra for split virtqueue Jason Wang
2021-04-21  3:21   ` Jason Wang
2021-04-22  6:31 ` [RFC PATCH 0/7] Untrusted device support for virtio Christoph Hellwig
2021-04-22  6:31   ` Christoph Hellwig
2021-04-22  8:19   ` Jason Wang
2021-04-22  8:19     ` Jason Wang
2021-04-23 20:14     ` Michael S. Tsirkin
2021-04-23 20:14       ` Michael S. Tsirkin
2021-04-25  1:43       ` Jason Wang
2021-04-25  1:43         ` Jason Wang
2021-04-28 21:06 ` Konrad Rzeszutek Wilk
2021-04-28 21:06   ` Konrad Rzeszutek Wilk
2021-04-29  4:16   ` Jason Wang
2021-04-29  4:16     ` Jason Wang
2021-06-04 15:17     ` Konrad Rzeszutek Wilk
2021-06-04 15:17       ` Konrad Rzeszutek Wilk
2021-06-07  2:46       ` Jason Wang
2021-06-07  2:46         ` Jason Wang

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