Hands-On System Programming with Linux

Thread capability sets

Within thread capsets, there are actually several types per thread.

Linux per-thread capability sets:

• Permitted (Prm): The overall limiting superset of effective capabilities for the thread. If a capability is dropped, it can never be reacquired.
• Inheritable (Inh): Inheritance here refers to the absorption of capset attributes across an exec. What happens to the capsets when a process executes another process? (Details on the exec are dealt with in a later chapter. For now, suffice it to say that if bash execs vi, then we call bash the predecessor and vi the successor). Will the successor process inherit the capsets of the predecessor? Well, yes the inheritable capset, that is. From the previous table, we can see that ...