On Tue, Oct 17, 2017 at 09:31:19AM -0400, Steven Rostedt wrote: > On Tue, 17 Oct 2017 15:52:51 +1100 > "Tobin C. Harding" <m...@tobin.cc> wrote: > > > Currently there are many places in the kernel where addresses are being > > printed using an unadorned %p. Kernel pointers should be printed using > > %pK allowing some control via the kptr_restrict sysctl. Exposing addresses > > gives attackers sensitive information about the kernel layout in memory. > > > > We can reduce the attack surface by hashing all addresses printed with > > %p. This will of course break some users, forcing code printing needed > > addresses to be updated. > > > > For what it's worth, usage of unadorned %p can be broken down as follows > > > > git grep '%p[^KFfSsBRrbMmIiEUVKNhdDgCGO]' | wc -l > > Does %p[FfSs] leak addresses? Well, I guess it does if they are not > found in kallsyms, but otherwise you have: > > function+0x<offset>
You are correct %pF and %pS print an offset. Does this provide an attack vector, I didn't think so but I'm no security expert. If they do then we need to amend those calls also. We still have %pa[pd] to see to as well obviously. thanks for the review, Tobin.
