diff options
| author | Michael S. Tsirkin <mst@redhat.com> | 2013-03-17 02:46:09 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2013-03-28 12:11:54 -0700 |
| commit | c2abe8ada7b63b6ede9c80e615fdbc97dde2e2e2 (patch) | |
| tree | 9002f32dd5e99c50d8176ea88d0bfe271eba1162 /drivers/vhost | |
| parent | 08ebc8f4c0acb1e9a104e66fdc2bb5b4e29171f5 (diff) | |
vhost/net: fix heads usage of ubuf_info
[ Upstream commit 46aa92d1ba162b4b3d6b7102440e459d4e4ee255 ]
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>
Cc: stable@kernel.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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 4134e53d7311..50a3cb5b589a 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -235,7 +235,8 @@ 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; |