Messages in this thread | | | Date | Sat, 26 Sep 2009 20:49:51 +0200 | From | Arjan van de Ven <> | Subject | [PATCH 0/9] Series to make copy_from_user to a stack slot provable right |
| |
[PATCH 0/9] Series to make copy_from_user to a stack slot provable right
This series contains a series of patches that, when applied, make every copy_from_user() in a make allyesconfig to a (direct) stack slot provable-by-gcc to have a correct size.
This is useful because if we fix all of these, we can make the non-provable case an error, as an indication of a possible security hole.
Now the series has 4 types of patches 1) changes where the original code really was missing checks 2) changes where the checks were coded so complex and games were played with types, that I (and the compiler) couldn't be sure if it was correct or not 3) changes where we're hitting a small gcc missing optimization, but where a simplification of the code allows gcc to prove things anyway. (http://gcc.gnu.org/bugzilla/show_bug.cgi?id=41477 is filed for this) 4) a case in sys_socketcall where Dave Miller and co were very smart in optimizing the code to the point where it's not reasonable for gcc to realize the result is ok.
-- Arjan van de Ven Intel Open Source Technology Centre For development, discussion and tips for power savings, visit http://www.lesswatts.org
| |