Commit fc6d70f4 authored by Xuan Zhuo's avatar Xuan Zhuo Committed by Michael S. Tsirkin
Browse files

virtio_ring: check desc == NULL when using indirect with packed 



When using indirect with packed, we don't check for allocation failures.
This patch checks that and fall back on direct.

Fixes: 1ce9e605 ("virtio_ring: introduce packed ring support")
Signed-off-by: default avatarXuan Zhuo <xuanzhuo@linux.alibaba.com>
Link: https://lore.kernel.org/r/20211020112323.67466-3-xuanzhuo@linux.alibaba.com


Signed-off-by: default avatarMichael S. Tsirkin <mst@redhat.com>
parent 8d7670f3

drivers/virtio/virtio_ring.c

+11 −3
Original line number Diff line number Diff line
@@ -1065,6 +1065,8 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq, 


	head = vq->packed.next_avail_idx;

	desc = alloc_indirect_packed(total_sg, gfp);

	if (!desc)

		return -ENOMEM;



	if (unlikely(vq->vq.num_free < 1)) {

		pr_debug("Can't add buf len 1 - avail = 0\n");
@@ -1176,6 +1178,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, 
	unsigned int i, n, c, descs_used, err_idx;

	__le16 head_flags, flags;

	u16 head, id, prev, curr, avail_used_flags;

	int err;



	START_USE(vq);
@@ -1191,9 +1194,14 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq, 


	BUG_ON(total_sg == 0);



	if (virtqueue_use_indirect(_vq, total_sg))

		return virtqueue_add_indirect_packed(vq, sgs, total_sg,

				out_sgs, in_sgs, data, gfp);

	if (virtqueue_use_indirect(_vq, total_sg)) {

		err = virtqueue_add_indirect_packed(vq, sgs, total_sg, out_sgs,

						    in_sgs, data, gfp);

		if (err != -ENOMEM)

			return err;



		/* fall back on direct */

	}



	head = vq->packed.next_avail_idx;

	avail_used_flags = vq->packed.avail_used_flags;