Messages in this thread | | | Date | Sat, 19 Nov 2011 20:59:03 +0400 | From | Solar Designer <> | Subject | Re: [PATCH 3/3] security: Yama: add ptrace relationship tracking interface |
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On Sat, Nov 19, 2011 at 08:30:58PM +0400, Vasiliy Kulikov wrote: > On Wed, Oct 26, 2011 at 16:49 -0700, Kees Cook wrote: > > + if (mode == PTRACE_MODE_ATTACH && > > + ptrace_scope && > > + !capable(CAP_SYS_PTRACE) && > > + !task_is_descendant(current, child) && > > + !ptracer_exception_found(current, child)) > > + rc = -EPERM; > > capable() is better to put after all other tests
Right, but...
> as a failed capable() > might emit a false positive warning into logs or something.
...primarily for another reason: a successful capable() sets PF_SUPERPRIV, whereas the permission might have been granted without capable() as well. The PF_SUPERPRIV flag is visible via BSD process accounting.
Alexander
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