vhost: fix possible out of bound access in relay helpers

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

Signed-off-by: Tiwei Bie <tiwei.bie@intel.com>
Reviewed-by: Maxime Coquelin <maxime.coquelin@redhat.com>

diff --git a/lib/librte_vhost/vdpa.c b/lib/librte_vhost/vdpa.c
index 77d92f9..407d1c3 100644 (file)
--- a/lib/librte_vhost/vdpa.c
+++ b/lib/librte_vhost/vdpa.c
@@ -178,6 +178,9 @@ rte_vdpa_relay_vring_avail(int vid, uint16_t qid, void *vring_m)
        while (idx_m != idx) {
                /* avail entry copy */
                desc_id = vq->avail->ring[idx_m & (vq->size - 1)];
+               if (unlikely(desc_id >= vq->size))
+                       return -1;
+
                s_vring->avail->ring[idx_m & (vq->size - 1)] = desc_id;
                desc_ring = vq->desc;
 
@@ -205,15 +208,14 @@ rte_vdpa_relay_vring_avail(int vid, uint16_t qid, void *vring_m)
 
                /* check if the buf addr is within the guest memory */
                do {
+                       if (unlikely(desc_id >= vq->size))
+                               goto fail;
                        desc = desc_ring[desc_id];
                        perm = desc.flags & VRING_DESC_F_WRITE ?
                                VHOST_ACCESS_WO : VHOST_ACCESS_RO;
                        if (invalid_desc_check(dev, vq, desc.addr, desc.len,
-                                               perm)) {
-                               if (unlikely(idesc))
-                                       free_ind_table(idesc);
-                               return -1;
-                       }
+                                               perm))
+                               goto fail;
                        desc_id = desc.next;
                } while (desc.flags & VRING_DESC_F_NEXT);
 
@@ -232,6 +234,11 @@ rte_vdpa_relay_vring_avail(int vid, uint16_t qid, void *vring_m)
                vhost_avail_event(vq) = idx;
 
        return ret;
+
+fail:
+       if (unlikely(idesc))
+               free_ind_table(idesc);
+       return -1;
 }
 
 int __rte_experimental
@@ -270,6 +277,9 @@ 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;
 
+               if (unlikely(desc_id >= vq->size))
+                       return -1;
+
                if (vq->desc[desc_id].flags & VRING_DESC_F_INDIRECT) {
                        dlen = vq->desc[desc_id].len;
                        desc_ring = (struct vring_desc *)(uintptr_t)
@@ -294,6 +304,8 @@ rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
 
                /* dirty page logging for DMA writeable buffer */
                do {
+                       if (unlikely(desc_id >= vq->size))
+                               goto fail;
                        desc = desc_ring[desc_id];
                        if (desc.flags & VRING_DESC_F_WRITE)
                                vhost_log_write(dev, desc.addr, desc.len);
@@ -315,4 +327,9 @@ rte_vdpa_relay_vring_used(int vid, uint16_t qid, void *vring_m)
                vring_used_event(s_vring) = idx_m;
 
        return ret;
+
+fail:
+       if (unlikely(idesc))
+               free_ind_table(idesc);
+       return -1;
 }