NULL pointer dereference in carp_vm_make()

Question

NULL pointer dereference in carp_vm_make()

Closed this issue 10 years ago · 2 comments

https://github.com/tekknolagi/carp/blob/master/src/carp_machine.c#L52 dereferences res although https://github.com/tekknolagi/carp/blob/master/src/carp_machine.c#L49 checked for res == NULL and https://github.com/tekknolagi/carp/blob/master/src/carp_machine.c#L50 certainly doesn't quit Carp.

Answer 1 · 2014-12-06T03:03:30.000Z

Why does it not quit Carp?

Answer 2 · 2014-12-06T11:55:37.000Z

Let's say res == NULL is true: carp_vm_err calls carp_vm_exit which sets m->regs[CARP_RUN] to 0. Then it unwinds back into carp_vm_make and you continue execution with setting m->regs[CARP_RUN] to 1. All in the meantime exit() not having been called at all. I understand that you want to exit carp on an error condition by setting the program code to exit carp, but I am almost certain separating VM code paths from program code paths is a good idea, at least it's simpler :)