Software versions of OpenWrt/LEDE release, packages, etc. 19.07.8
Steps to reproduce
Use a tool like netcat to open many (i.e 20+) TCP connections to port 53, simulating TCP dns queries
Observe how dnsmasq forks for each connection
Observe how at some point enough dnsmasq children are running that the kernel starts OOMing
This is a quick/easy demonstration on how simply an OpenWRT router can be DoS attacked.
There is a hard coded MAX_PROCS which defaults to 20. This clearly is too high for resource constrained systems like OpenWRT routers.