On 28/06/17 18:09, Daniel Borkmann wrote: > Could you elaborate on this one? If I understand it correctly, then > the scalar += pointer case would mean the following: given I have one > of the allowed pointer types in adjust_ptr_min_max_vals() then the > prior scalar type inherits the ptr type/id. I would then 'destroy' the > pointer value so we get a -EACCES on it. We mark the tmp off_reg as > scalar type, but shouldn't also actual dst_reg be marked as such > like in below pointer += scalar case, such that we undo the prior > ptr_type inheritance? Good catch. The intent was that adjust_ptr_min_max_vals() wouldn't mark dst_reg's type/id in the case when it returned -EACCES, but indeed there are some such paths, and rather than changing those it may be easier to change the type/id back to scalar/0. I don't think we need to go as far as calling __mark_reg_unknown() on it though, its bounds and align shouldn't have been screwed up by adjust_ptr_min_max_vals().
-Ed
