On Mar 3, 2011, at 5:30 PM, Dan Rosenberg wrote: > I appreciate your input on this, you've made very reasonable points. > I'm just not convinced that those few real users are being substantially > inconvenienced, even if there's only a small benefit for the larger > population of users who are at risk for attacks. Perhaps others could > contribute their opinions to the discussion. Being able to monitor /proc/slabinfo is incredibly useful for finding various kernel problems. We can see if some part of the kernel is out of balance, and we can also find memory leaks. I once saved a school system's Linux deployment because their systems were crashing once a week, and becoming progressively more unreliable before they crashed, and the school board was about to pull the plug. Turned out the "virus scanner" was a piece of garbage that slowly leaked memory over time, and since it was proprietary code that was loaded as a kernel module, it showed up in /proc/slabinfo. If it had been protected it would have been much harder for me to get access to such debugging data. I wonder if there is some other change we could make to the slab allocator that would make it harder for exploit writers without having to protect the /proc/slabinfo file. For example, could we randomly select different free objects in a page instead of filling them in sequentially? -- Ted -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>