[hra5th]

In addition to the other comment, the primary problem with malloc() in embedded environments is that you push the memory exhaustion error to runtime, rather than compile time (not memory fragmentation). A call to malloc() in a rarely-called function might not exhaust available RAM until a system has been deployed for days or weeks, which is much worse than finding out your program requires too much memory at compile time, or at boot time. While stack overflows are always possible, many embedded projects at least have static analysis tools that can (with varying degrees of soundness) calculate worst-case stack use.