Michael Brown
de2616165b
[xfer] Avoid using stack-allocated memory in xfer_printf()
xfer_printf() occasionally has to deal with strings that are
potentially long, such as HTTP URIs with multiple query parameters.
Allocating these on the stack can lead to stack overruns and memory
corruption.
Fix by using vasprintf() instead of a stack allocation.
Signed-off-by: Michael Brown <mcb30@ipxe.org>