diff mbox series

[3/6] vhost: fix possible dead loop in relay helpers

Message ID 20190104040642.27463-4-tiwei.bie@intel.com (mailing list archive)
State Accepted, archived
Delegated to: Maxime Coquelin
Headers
Series Some fixes for vhost |

Checks

Context Check Description
ci/checkpatch success coding style OK
ci/Intel-compilation success Compilation OK

Commit Message

Tiwei Bie Jan. 4, 2019, 4:06 a.m. UTC 
  Fix a possible dead loop which may happen, e.g. when
driver created a loop in the desc list.

Fixes: b13ad2decc83 ("vhost: provide helpers for virtio ring relay")

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
---
 lib/librte_vhost/vdpa.c | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

Comments

Maxime Coquelin Jan. 4, 2019, 8:40 a.m. UTC | #1 
On 1/4/19 5:06 AM, Tiwei Bie wrote:
> Fix a possible dead loop which may happen, e.g. when
> driver created a loop in the desc list.
> 
> Fixes: b13ad2decc83 ("vhost: provide helpers for virtio ring relay")
> 
> Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
> ---
>   lib/librte_vhost/vdpa.c | 16 ++++++++++++++++
>   1 file changed, 16 insertions(+)
> 

Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

Thanks,
Maxime
diff mbox series

Patch

diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c
index 407d1c363..02083bb8a 100644
--- a/lib/librte_vhost/vdpa.c
+++ b/lib/librte_vhost/vdpa.c
@@ -157,6 +157,7 @@  rte_vdpa_relay_vring_avail(int vid, uint16_t qid, void *vring_m)
 	struct vring_desc *idesc = NULL;
 	struct vring *s_vring;
 	uint64_t dlen;
+	uint32_t nr_descs;
 	int ret;
 	uint8_t perm;
 
@@ -183,9 +184,14 @@  rte_vdpa_relay_vring_avail(int vid, uint16_t qid, void *vring_m)
 
 		s_vring->avail->ring[idx_m & (vq->size - 1)] = desc_id;
 		desc_ring = vq->desc;
+		nr_descs = vq->size;
 
 		if (vq->desc[desc_id].flags & VRING_DESC_F_INDIRECT) {
 			dlen = vq->desc[desc_id].len;
+			nr_descs = dlen / sizeof(struct vring_desc);
+			if (unlikely(nr_descs > vq->size))
+				return -1;
+
 			desc_ring = (struct vring_desc *)(uintptr_t)
 				vhost_iova_to_vva(dev, vq,
 						vq->desc[desc_id].addr, &dlen,
@@ -210,6 +216,8 @@  rte_vdpa_relay_vring_avail(int vid, uint16_t qid, void *vring_m)
 		do {
 			if (unlikely(desc_id >= vq->size))
 				goto fail;
+			if (unlikely(nr_descs-- == 0))
+				goto fail;
 			desc = desc_ring[desc_id];
 			perm = desc.flags & VRING_DESC_F_WRITE ?
 				VHOST_ACCESS_WO : VHOST_ACCESS_RO;
@@ -252,6 +260,7 @@  rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
 	struct vring_desc *idesc = NULL;
 	struct vring *s_vring;
 	uint64_t dlen;
+	uint32_t nr_descs;
 	int ret;
 
 	if (!dev || !vring_m)
@@ -276,12 +285,17 @@  rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
 
 		desc_id = vq->used->ring[idx & (vq->size - 1)].id;
 		desc_ring = vq->desc;
+		nr_descs = vq->size;
 
 		if (unlikely(desc_id >= vq->size))
 			return -1;
 
 		if (vq->desc[desc_id].flags & VRING_DESC_F_INDIRECT) {
 			dlen = vq->desc[desc_id].len;
+			nr_descs = dlen / sizeof(struct vring_desc);
+			if (unlikely(nr_descs > vq->size))
+				return -1;
+
 			desc_ring = (struct vring_desc *)(uintptr_t)
 				vhost_iova_to_vva(dev, vq,
 						vq->desc[desc_id].addr, &dlen,
@@ -306,6 +320,8 @@  rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
 		do {
 			if (unlikely(desc_id >= vq->size))
 				goto fail;
+			if (unlikely(nr_descs-- == 0))
+				goto fail;
 			desc = desc_ring[desc_id];
 			if (desc.flags & VRING_DESC_F_WRITE)
 				vhost_log_write(dev, desc.addr, desc.len);