Re: [patch] let CONFIG_SECCOMP default to n

Ingo Molnar
2006-07-13T11:41:30Z

* Jeff Dike <jdike@addtoit.com> wrote:

> Now, there were a couple of ways to legitimately escape from UML, and
> they *did* involve ptrace. Things like single-stepping a system call
> instruction or putting a breakpoint on a system call instruction and
> single-stepping from the breakpoint. As far as I know, these were
> discovered and fixed by UML developers before there was any outside
> awareness of these bugs.

also, UML 'ptrace clients' are allowed alot more leeway than what a
seccomp-alike ptrace/utrace based syscall filter would allow. It would
clearly exclude activities like 'setting a breakpoint' or
'single-stepping' - valid syscalls would be limited to
read/write/sigreturn/exit.

Ingo