[3/6] vhost: fix possible dead loop in relay helpers
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Commit Message
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
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
@@ -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);