Articles

Buffer overflows: quick mental model

The stack is just bytes. Functions place local buffers on the stack next to saved state (saved base pointer and the return address).

If input writes more than the buffer can hold, it overwrites whatever comes next. Classic target: the saved return address (RIP). If you overwrite it, you control where the program returns.

Tip: On x86_64, sometimes insert one extra ret to fix stack alignment.

DDS in ROS 2: what matters

DDS is the middleware that moves messages between nodes. Most issues come down to QoS: reliability, history depth, and whether messages should be kept for late joiners.

For high-rate sensor streams, best-effort often avoids stalls. For critical commands, reliable makes sense. Tune QoS per topic.