net: vmw_vsock: vmci: Check memcpy_from_msg()

vmci_transport_dgram_enqueue() does not check the return value
of memcpy_from_msg().  If memcpy_from_msg() fails, it is possible that
uninitialized memory contents are sent unintentionally instead of user's
message in the datagram to the destination.  Return with an error if
memcpy_from_msg() fails.

Found by Linux Verification Center (linuxtesting.org) with SVACE.

Fixes: 0f7db23a07af ("vmci_transport: switch ->enqeue_dgram, ->enqueue_stream and ->dequeue_stream to msghdr")
Signed-off-by: Artem Chernyshev <artem.chernyshev@red-soft.ru>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Reviewed-by: Vishnu Dasa <vdasa@vmware.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/vmw_vsock/vmci_transport.c b/net/vmw_vsock/vmci_transport.c
index 842c94286d316af337fa2fa9f3a598284bf2f306..36eb16a40745d2fc07f3a8dd5c81396c20320843 100644 (file)
--- a/net/vmw_vsock/vmci_transport.c
+++ b/net/vmw_vsock/vmci_transport.c
@@ -1711,7 +1711,11 @@ static int vmci_transport_dgram_enqueue(
        if (!dg)
                return -ENOMEM;
 
-       memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len);
+       err = memcpy_from_msg(VMCI_DG_PAYLOAD(dg), msg, len);
+       if (err) {
+               kfree(dg);
+               return err;
+       }
 
        dg->dst = vmci_make_handle(remote_addr->svm_cid,
                                   remote_addr->svm_port);