virtio: packed: fix unmap leak for indirect desc table

[ Upstream commit d5c0ed17fea60cca9bc3bf1278b49ba79242bbcd ]

When use_dma_api and premapped are true, then the do_unmap is false.

Because the do_unmap is false, vring_unmap_extra_packed is not called by
detach_buf_packed.

  if (unlikely(vq->do_unmap)) {
                curr = id;
                for (i = 0; i < state->num; i++) {
                        vring_unmap_extra_packed(vq,
                                                 &vq->packed.desc_extra[curr]);
                        curr = vq->packed.desc_extra[curr].next;
                }
  }

So the indirect desc table is not unmapped. This causes the unmap leak.

So here, we check vq->use_dma_api instead. Synchronously, dma info is
updated based on use_dma_api judgment

This bug does not occur, because no driver use the premapped with
indirect.

Fixes: b319940f83c2 ("virtio_ring: skip unmap for premapped")
Signed-off-by: Xuan Zhuo <xuanzhuo@linux.alibaba.com>
Message-Id: <20240223071833.26095-1-xuanzhuo@linux.alibaba.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/virtio/virtio_ring.c b/drivers/virtio/virtio_ring.c
index 49299b1f9ec746bcfae28186c7644092c4849fd8..6f7e5010a6735daf093952bad0025f0acd356253 100644 (file)
--- a/drivers/virtio/virtio_ring.c
+++ b/drivers/virtio/virtio_ring.c
@@ -1340,7 +1340,7 @@ static int virtqueue_add_indirect_packed(struct vring_virtqueue *vq,
                                sizeof(struct vring_packed_desc));
        vq->packed.vring.desc[head].id = cpu_to_le16(id);
 
-       if (vq->do_unmap) {
+       if (vq->use_dma_api) {
                vq->packed.desc_extra[id].addr = addr;
                vq->packed.desc_extra[id].len = total_sg *
                                sizeof(struct vring_packed_desc);
@@ -1481,7 +1481,7 @@ static inline int virtqueue_add_packed(struct virtqueue *_vq,
                        desc[i].len = cpu_to_le32(sg->length);
                        desc[i].id = cpu_to_le16(id);
 
-                       if (unlikely(vq->do_unmap)) {
+                       if (unlikely(vq->use_dma_api)) {
                                vq->packed.desc_extra[curr].addr = addr;
                                vq->packed.desc_extra[curr].len = sg->length;
                                vq->packed.desc_extra[curr].flags =
@@ -1615,7 +1615,7 @@ static void detach_buf_packed(struct vring_virtqueue *vq,
        vq->free_head = id;
        vq->vq.num_free += state->num;
 
-       if (unlikely(vq->do_unmap)) {
+       if (unlikely(vq->use_dma_api)) {
                curr = id;
                for (i = 0; i < state->num; i++) {
                        vring_unmap_extra_packed(vq,