On Sat, Jun 30, 2012 at 2:14 AM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > On Mon, Jun 25, 2012 at 02:05:26PM -0700, Kees Cook wrote: > >> +config PROTECTED_LINKS >> + bool "Evaluate vulnerable link conditions" >> + default y > > Remember Linus' rants about 'default y' in general? I added these configs due to other people's requests. I am happy to remove them all and have the sysctls start their life == 1. It would eliminate all the #ifdef logic too. >> + /* Check parent directory mode and owner. */ > > I suspect that we ought to simply pass that parent directory as argument - caller > *does* have a reference to it, so we don't need to mess with ->d_lock, etc. I don't see where the parent is held in either path_openat nor path_lookupat. What should I be passing into may_follow_link() for the parent? >> + err = may_follow_link(&link); >> + if (unlikely(err)) >> + break; > > No. This is definitely wrong - you are leaking dentries and vfsmount here. What should I do to avoid the leak? I thought it was avoiding the need to call put_link because it aborts before calling follow_link. >> + error = may_follow_link(&link); >> + if (unlikely(error)) >> + break; > > Ditto. Same thing here -- it aborts before the follow_link. I must be misunderstanding something. What am I missing? Thanks for the feedback! I'll clean up the other things you mentioned as well. -Kees -- Kees Cook Chrome OS Security -- To unsubscribe from this list: send the line "unsubscribe linux-doc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
