On Thu, Mar 21, 2019 at 6:55 AM Steven Rostedt <rost...@goodmis.org> wrote: > > Looks to be an issue with the save_stack_trace_user() not checking if > the address is canonical before reading it. I guess access_ok() doesn't > check that.
access_ok() definitely does check for non-canonical. But it only does so when USER_DS is in effect. If you use KERNEL_DS, then you have to check the address yourself. Linus