Hey you know what, I've used dd to write into process memory but haven't actually used it to disable KASLR, so it's possible I am misremembering. My bad.
:(
Sounds super 1337 and I hope it's actually possible somehow.
Parse /proc/<pid>/maps to find the relevant target_addr in your process-under-attack. And then its a matter of:
$ dd if=shellcode.bin of=/proc/<pid>/mem bs=1 seek=$((target_addr)) ...