On Fri, Aug 12, 2005 at 09:35:03AM -0700, Linus Torvalds wrote: > On Thu, 11 Aug 2005, Steven Rostedt wrote: > > > > Found the problem. It is a bug with mmap_kmem. The order of checks is > > wrong, so here's the patch. Attached is a little program that reads the > > System map looking for the variable modprobe_path. If it finds it, then > > it opens /dev/kmem for read only and mmaping it to read the contents of > > modprobe_path. > > I'm actually more inclined to try to deprecate /dev/kmem.. I don't think > anybody has ever really used it except for some rootkits. It only exists > in the first place because it's historical.
We've had it disabled in Fedora for a long time, maybe as far back as FC2, for exactly this reason. The only things that broke, were things that needed fixing anyway. (Something like gdm was reading /dev/mem to get a source of random numbers of all things). > We do need to support /dev/mem for X, but even that might go away some > day. We also restrict /dev/mem to be a 'need to know' basis. Trying to read from certain regions of memory will fail. Again, nothing that wasn't already broken broke with this change. > So I'd be perfectly happy to fix this, but I'd be even happier if we made > the whole kmem thing a config variable (maybe even default it to "off"). The above patches were in -mm for a while, though they didn't have a config option, they just 'did it', and some of the changes were a bit unclean, but I can polish that up if you're interested. Dave - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/