On Sat 2015-01-03 00:00:22, Richard Weinberger wrote: > Am 02.01.2015 um 23:54 schrieb Pavel Machek: > > On Fri 2015-01-02 23:49:52, Jiri Kosina wrote: > >> On Fri, 2 Jan 2015, Pavel Machek wrote: > >> > >>>> You also want to protect against binaries that are evil on purpose, > >>>> right? > >>> > >>> Umm. No. Not by default. We don't want to break crashme or trinity by > >>> default. > >> > >> I thought trinity is issuing syscalls directly (would make more sense than > >> going through glibc, wouldn't it?) ... haven't checked the source though. > > > > Patch in this thread wanted to insert delays into kernel on SIGSEGV > > processing. That's bad idea by default. > > No. This is not what this patch does. > > > But changing glibc to do sleep(30); abort(); instead of abort(); to > > slow down bruteforcing of canaries makes some kind of sense... and > > should be ok by default. > > As I saidn only focusing one the specific stack canary case is not enough. Ok, so I am now saying "adding random delays to the kernel, hoping they slow attacker down" is bad idea. Feel free to add my NAK to the patch. If really neccessary, "kill_me_slowly()" syscall would be acceptable, but it seems just sleep(); abort(); combination is enough. glibc should cover 99% cases where this matters, please just fix glibc, others will follow. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
