From 278f72e8eb572a5f392cb291566b9d4c9ea68dc8 Mon Sep 17 00:00:00 2001 From: Stefano Garzarella Date: Mon, 22 Nov 2021 17:35:24 +0100 Subject: [PATCH] vhost/vsock: fix incorrect used length reported to the guest commit 49d8c5ffad07ca014cfae72a1b9b8c52b6ad9cb8 upstream. The "used length" reported by calling vhost_add_used() must be the number of bytes written by the device (using "in" buffers). In vhost_vsock_handle_tx_kick() the device only reads the guest buffers (they are all "out" buffers), without writing anything, so we must pass 0 as "used length" to comply virtio spec. Fixes: 433fc58e6bf2 ("VSOCK: Introduce vhost_vsock.ko") Cc: stable@vger.kernel.org Reported-by: Halil Pasic Suggested-by: Jason Wang Signed-off-by: Stefano Garzarella Link: https://lore.kernel.org/r/20211122163525.294024-2-sgarzare@redhat.com Signed-off-by: Michael S. Tsirkin Reviewed-by: Stefan Hajnoczi Reviewed-by: Halil Pasic Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/vsock.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c index 938aefb..4e3b95a 100644 --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -554,7 +554,7 @@ static void vhost_vsock_handle_tx_kick(struct vhost_work *work) virtio_transport_free_pkt(pkt); len += sizeof(pkt->hdr); - vhost_add_used(vq, head, len); + vhost_add_used(vq, head, 0); total_len += len; added = true; } while(likely(!vhost_exceeds_weight(vq, ++pkts, total_len))); -- 2.7.4