Merge 5.18-rc5 into char-misc-next

We need the char-misc fixes in here as well.

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

1 files changed, 19 insertions, 1 deletions

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 87838cbe38cf..cbba9d2e8f32 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -1005,6 +1005,24 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 			 * xdp.data_meta were adjusted
 			 */
 			len = xdp.data_end - xdp.data + vi->hdr_len + metasize;
+
+			/* recalculate headroom if xdp.data or xdp_data_meta
+			 * were adjusted, note that offset should always point
+			 * to the start of the reserved bytes for virtio_net
+			 * header which are followed by xdp.data, that means
+			 * that offset is equal to the headroom (when buf is
+			 * starting at the beginning of the page, otherwise
+			 * there is a base offset inside the page) but it's used
+			 * with a different starting point (buf start) than
+			 * xdp.data (buf start + vnet hdr size). If xdp.data or
+			 * data_meta were adjusted by the xdp prog then the
+			 * headroom size has changed and so has the offset, we
+			 * can use data_hard_start, which points at buf start +
+			 * vnet hdr size, to calculate the new headroom and use
+			 * it later to compute buf start in page_to_skb()
+			 */
+			headroom = xdp.data - xdp.data_hard_start - metasize;
+
 			/* We can only create skb based on xdp_page. */
 			if (unlikely(xdp_page != page)) {
 				rcu_read_unlock();
@@ -1012,7 +1030,7 @@ static struct sk_buff *receive_mergeable(struct net_device *dev,
 				head_skb = page_to_skb(vi, rq, xdp_page, offset,
 						       len, PAGE_SIZE, false,
 						       metasize,
-						       VIRTIO_XDP_HEADROOM);
+						       headroom);
 				return head_skb;
 			}
 			break;