From 99975cc6ada0d5f2675e83abecae05aba5f437d2 Mon Sep 17 00:00:00 2001 From: "Michael S. Tsirkin" Date: Wed, 7 Jan 2015 10:51:00 +0200 Subject: [PATCH] vhost/net: length miscalculation commit 8b38694a2dc8b18374310df50174f1e4376d6824 vhost/net: virtio 1.0 byte swap had this chunk: - heads[headcount - 1].len += datalen; + heads[headcount - 1].len = cpu_to_vhost32(vq, len - datalen); This adds datalen with the wrong sign, causing guest panics. Fixes: 8b38694a2dc8b18374310df50174f1e4376d6824 Reported-by: Alex Williamson Suggested-by: Greg Kurz Signed-off-by: Michael S. Tsirkin --- drivers/vhost/net.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 14419a8ccbb6..d415d69dc237 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -538,7 +538,7 @@ static int get_rx_bufs(struct vhost_virtqueue *vq, ++headcount; seg += in; } - heads[headcount - 1].len = cpu_to_vhost32(vq, len - datalen); + heads[headcount - 1].len = cpu_to_vhost32(vq, len + datalen); *iovcount = seg; if (unlikely(log)) *log_num = nlogs; -- 2.30.2