From 8acd7c21335305426fbbc0a3aea2978734d0b2a8 Mon Sep 17 00:00:00 2001 From: Maxime Coquelin Date: Mon, 19 Oct 2020 19:34:09 +0200 Subject: [PATCH] vhost: fix virtqueues metadata allocation The Vhost-user backend implementation assumes there will be no holes in the device's array of virtqueues metadata pointers. It can happen though, and would cause segmentation faults, memory leaks or undefined behaviour. This patch keep the assumption that there is no holes in this array, and allocate all uninitialized virtqueues metadata up to requested index. Fixes: 160cbc815b41 ("vhost: remove a hack on queue allocation") Cc: stable@dpdk.org Suggested-by: Adrian Moreno Signed-off-by: Maxime Coquelin Reviewed-by: Chenbo Xia --- lib/librte_vhost/vhost.c | 33 ++++++++++++++++++++------------- 1 file changed, 20 insertions(+), 13 deletions(-) diff --git a/lib/librte_vhost/vhost.c b/lib/librte_vhost/vhost.c index 6068c38ec6..0c9ba3b3af 100644 --- a/lib/librte_vhost/vhost.c +++ b/lib/librte_vhost/vhost.c @@ -579,22 +579,29 @@ int alloc_vring_queue(struct virtio_net *dev, uint32_t vring_idx) { struct vhost_virtqueue *vq; + uint32_t i; - vq = rte_malloc(NULL, sizeof(struct vhost_virtqueue), 0); - if (vq == NULL) { - VHOST_LOG_CONFIG(ERR, - "Failed to allocate memory for vring:%u.\n", vring_idx); - return -1; - } + /* Also allocate holes, if any, up to requested vring index. */ + for (i = 0; i <= vring_idx; i++) { + if (dev->virtqueue[i]) + continue; - dev->virtqueue[vring_idx] = vq; - init_vring_queue(dev, vring_idx); - rte_spinlock_init(&vq->access_lock); - vq->avail_wrap_counter = 1; - vq->used_wrap_counter = 1; - vq->signalled_used_valid = false; + vq = rte_malloc(NULL, sizeof(struct vhost_virtqueue), 0); + if (vq == NULL) { + VHOST_LOG_CONFIG(ERR, + "Failed to allocate memory for vring:%u.\n", i); + return -1; + } + + dev->virtqueue[i] = vq; + init_vring_queue(dev, vring_idx); + rte_spinlock_init(&vq->access_lock); + vq->avail_wrap_counter = 1; + vq->used_wrap_counter = 1; + vq->signalled_used_valid = false; + } - dev->nr_vring += 1; + dev->nr_vring = RTE_MAX(dev->nr_vring, vring_idx + 1); return 0; } -- 2.20.1