diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2013-03-17 02:46:09 +0000 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2013-03-27 02:41:02 +0000 |
| commit | 984cbc9c6686f399cb4ec5bd8fae5ff8ec2fa9a8 (patch) | |
| tree | b1f0e64e6e06609fb038367af3ff85b706005794 /drivers/vhost | |
| parent | d86449a761337092171d90ea295ac745b05f384a (diff) | |
vhost/net: fix heads usage of ubuf_info
commit 46aa92d1ba162b4b3d6b7102440e459d4e4ee255 upstream.
ubuf info allocator uses guest controlled head as an index,
so a malicious guest could put the same head entry in the ring twice,
and we will get two callbacks on the same value.
To fix use upend_idx which is guaranteed to be unique.
Reported-by: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Diffstat (limited to 'drivers/vhost')
| -rw-r--r-- | drivers/vhost/net.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index b76071e12ce..5c5812860ec 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -234,7 +234,8 @@ static void handle_tx(struct vhost_net *net) msg.msg_controllen = 0; ubufs = NULL; } else { - struct ubuf_info *ubuf = &vq->ubuf_info[head]; + struct ubuf_info *ubuf; + ubuf = vq->ubuf_info + vq->upend_idx; vq->heads[vq->upend_idx].len = len; ubuf->callback = vhost_zerocopy_callback; |