> On Jun 19, 2018, at 1:12 PM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: > >> On Tue, Jun 19, 2018 at 10:20 AM, Andy Lutomirski <luto@xxxxxxxxxxxxxx> wrote: >> >>> On Jun 19, 2018, at 10:07 AM, Kees Cook <keescook@xxxxxxxxxxxx> wrote: >>> >>> Does it provide anything beyond what PR_DUMPABLE does? >> >> What do you mean? > > I was just going by the name of it. I wasn't sure what "ptrace CET > lock" meant, so I was trying to understand if it was another "you > can't ptrace me" toggle, and if so, wouldn't it be redundant with > PR_SET_DUMPABLE = 0, etc. > No, other way around. The valid CET states are on/unlocked, off/unlocked, on/locked, off/locked. arch_prctl can freely the state unless locked. ptrace can change it no matter what. The lock is to prevent the existence of a gadget to disable CET (unless the gadget involves ptrace, but I don’t think that’s a real concern).
