On Wed, Jan 25, 2012 at 3:30 PM, Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> wrote: > On Mon, 23 Jan 2012 13:21:15 -0800 > Kees Cook <keescook@xxxxxxxxxxxx> wrote: >> Add the "proc_pid_mem" sysctl to control whether or not /proc/pid/mem is >> allowed to work: 0: disabled, 1: read only, 2: read/write (default). > > I agree with Colin on this (he stole my line!). > > Overall, the patch looks really hacky and random. I felt the same way > as Vasily: it's easy to see how a significant number of similar (and > hacky and random) patches could be added, resulting in a regrettable > mess. > > Is there some better designed, more organized way of approaching all of > this? Random ideas: > > - A parallel /procfs-perms filesystem. You write a number into > /procfs-perms/stat to affect access to /proc/stat (although why the > heck not just run `chmod /proc/stat'?) It's unclear how to handle > /proc/pid/. Perhaps literally have a /procfs-perms/pid/ directory. This seems like too much overhead to me. > - Make tasks inherit their /proc/pid/* permissions across fork, do a > chmod /proc/1/whatever in initscripts. This is actually pretty interesting. I think as long as it only allowed the _reduction_ of access. I don't want a process to open up access, just restrict it further. It does make me wonder what the side-effects would be, though. Dropping user r/w perms to things for non-DAC_OVERRIDE processes would be ... weird. -Kees -- Kees Cook ChromeOS 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
