On Fri, Mar 15, 2013 at 08:48:49AM -0700, Luigi Semenzato wrote: > On Fri, Mar 15, 2013 at 2:04 AM, Ric Mason <ric.masonn@xxxxxxxxx> wrote: > > On 03/12/2013 07:57 AM, Luigi Semenzato wrote: > >> > >> Greetings linux-mmers, > >> > >> before we can fully deploy zram, we must ensure it conforms to the > >> Chrome OS security requirements. In particular, we do not want to > >> allow user space to read/write the swap device---not even root-owned > >> processes. > > > > > > Interesting. > > Thank you. > > >> > >> A similar restriction is available for /dev/mem under > >> CONFIG_STRICT_DEVMEM. > > > > > > Sorry, what's /dev/mem used for? and why relevant your topic? > > I don't know what it's used for Chrome OS, but I don't think it > matters. The point is that /dev/mem is compiled in the kernel, and > without CONFIG_STRICT_DEVMEM it offers a way for a root-owned process > to read/write all of physical memory. The situation is not as dire > with a swap device, but currently a root-owned process can open a > block device used for swap and peek and poke its data, which means > that a root-owned process has now potential access to the data segment > of any other process, among other things. How do you handle /proc/<pid>/mem? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>