On Fri, 2013-02-08 at 11:21 -0800, Kees Cook wrote: > On Fri, Feb 8, 2013 at 11:17 AM, Matthew Garrett > wrote: > > On Fri, 2013-02-08 at 11:12 -0800, Kees Cook wrote: > >> Writing to MSRs should not be allowed unless CAP_COMPROMISE_KERNEL is > >> set since it could lead to execution of arbitrary code in kernel mode. > > > > Willing to buy this, but do you have a description of one potential > > approach? We should probably also figure out what's writing to MSRs at > > the moment (anything other than energy_perf_bias?) and decide what the > > best thing to do there is. > > Yes, change the SYSENTER entry point to where-ever you like. There are > examples already written: > http://grsecurity.net/~spender/msr32.c Cool. Yup, this sounds like a good plan. ÿôèº{.nÇ+‰·Ÿ®‰­†+%ŠËÿ±éݶ¥Šwÿº{.nÇ+‰·¥Š{±þG«�éÿŠ{ayºʇڙë,j­¢f£¢·hš�ï�êÿ‘êçz_è®(­éšŽŠÝ¢j"�ú¶m§ÿÿ¾«þG«�éÿ¢¸?™¨è­Ú&£ø§~�á¶iO•æ¬z·švØ^¶m§ÿÿà ÿ¶ìÿ¢¸?–I¥