3.5.7.9 -stable review patch. If anyone has any objections, please let me know.
------------------ From: "Michael S. Tsirkin" <[email protected]> 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 <[email protected]> Signed-off-by: Michael S. Tsirkin <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Luis Henriques <[email protected]> --- drivers/vhost/net.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 3c4dcc3d9..f2e8236 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; -- 1.8.1.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
