Commit 680d04e0 authored Apr 07, 2013 by Mathias Krause Committed by David S. Miller Apr 07, 2013

VSOCK: vmci - fix possible info leak in vmci_transport_dgram_dequeue()



In case we received no data on the call to skb_recv_datagram(), i.e.
skb->data is NULL, vmci_transport_dgram_dequeue() will return with 0
without updating msg_namelen leading to net/socket.c leaking the local,
uninitialized sockaddr_storage variable to userland -- 128 bytes of
kernel stack memory.

Fix this by moving the already existing msg_namelen assignment a few
lines above.

Cc: Andy King <acking@vmware.com>
Cc: Dmitry Torokhov <dtor@vmware.com>
Cc: George Zhang <georgezhang@vmware.com>
Signed-off-by: Mathias Krause <minipli@googlemail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

parent 60085c3d

net/vmw_vsock/vmci_transport.c

+2 −1

Original line number	Diff line number	Diff line
		@@ -1736,6 +1736,8 @@ static int vmci_transport_dgram_dequeue(struct kiocb *kiocb,
		if (flags & MSG_OOB \|\| flags & MSG_ERRQUEUE)
		return -EOPNOTSUPP;

		msg->msg_namelen = 0;

		/* Retrieve the head sk_buff from the socket's receive queue. */
		err = 0;
		skb = skb_recv_datagram(&vsk->sk, flags, noblock, &err);
		@@ -1768,7 +1770,6 @@ static int vmci_transport_dgram_dequeue(struct kiocb *kiocb,
		if (err)
		goto out;

		msg->msg_namelen = 0;
		if (msg->msg_name) {
		struct sockaddr_vm *vm_addr;