commit 1f691b07 upstream.

Though clients we care about mostly don't do this, it is possible for
rpc requests to be sent in multiple fragments.  Here we have a sanity
check to ensure that the final received rpc isn't too small--except that
the number we're actually checking is the length of just the final
fragment, not of the whole rpc.  So a perfectly legal rpc that's
unluckily fragmented could cause the server to close the connection
here.
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>