On Wed, Mar 25, 2020 at 05:20:40PM -0500, Eric W. Biederman wrote: > Hmm. There is a big gotcha in here and I think it should be mentioned. > This code only works because no one has done set_fs(KERNEL_DS). Which > means this only works with strings that are kernel addresses essentially > by mistake. A big fat comment documenting why it is safe to pass in > kernel addresses to a function that takes a "char __user*" pointer > would be very good. Yeah, I was going to mention this too just now as I went looking through one of the handlers and was reminded that the args are marked __user. :P I suspect we might need to add some __force __user markings or something (with a comment as you say above), to keep sparse from going crazy. :) -- Kees Cook
