On Fri, Jun 26, 2020 at 03:20:35PM +0900, Tetsuo Handa wrote: > On 2020/06/26 14:41, Alexei Starovoitov wrote: > >> I was hoping that fork_usermode_blob() accepts only simple program > >> like the content of "hello64" generated by > > > > pretty much. statically compiled elf that is self contained. > > But fork_usermode_blob() itself does not check that. As I said few emails back it's trivial to add such check. > > In the future it would be trivial to add a new ptrace flag to > > make sure that blob's memory is not ptraceable from the start. > > I guess it is some PF_* flag (like PF_KTHREAD is used for avoiding some interference). Kinda. I was thinking about PTRACE_MODE_xxx flag. > What I am hoping is that we can restrict interference between usermode blob processes > and other processes without using LSMs, I don't see why not. Extra piece of mind that blob memory is untouchable by other root processes is nice to have.
