From: "Michael S. Tsirkin" <mst@redhat.com>
To: linux-kernel@vger.kernel.org
Cc: Alex Williamson <alex.williamson@redhat.com>,
Greg Kurz <gkurz@linux.vnet.ibm.com>,
kvm@vger.kernel.org, virtualization@lists.linux-foundation.org,
netdev@vger.kernel.org
Subject: [PATCH] vhost/net: length miscalculation
Date: Wed, 7 Jan 2015 10:55:55 +0200 [thread overview]
Message-ID: <1420620847-24477-1-git-send-email-mst@redhat.com> (raw)
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 <alex.williamson@redhat.com>
Suggested-by: Greg Kurz <gkurz@linux.vnet.ibm.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
Alex, could you please confirm this fixes the crash for you?
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 14419a8..d415d69 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;
--
MST
next reply other threads:[~2015-01-07 8:56 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-01-07 8:55 Michael S. Tsirkin [this message]
2015-01-07 15:09 ` [PATCH] vhost/net: length miscalculation Alex Williamson
2015-01-07 20:58 ` Sergei Shtylyov
2015-01-08 8:08 ` Michael S. Tsirkin
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