On Fri, Apr 25, 2014 at 09:39:57PM +0530, Kumar Gaurav wrote: > Hence when transferring data involves loops then checking permission > (using access_ok()) once should be good to go then after we can > simply transfer data using __put_user(), instead of using put_user() > itself in loop. > Well, I can't tell you whether this is a good idea, but: This looks correct and other code is doing this already. However, put_user calls might_fault, but __put_user consumers I found (e.g. copy_siginfo_to_user) don't do that. While it has only debugging purposes and would not change anything for those consumers, it seems to be a bug to not include it. Thus I suggest adding access_ok variant which calls might_fault. -- Mateusz Guzik -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html