On Tue, Dec 19, 2017 at 09:12:58AM +0100, Dmitry Vyukov wrote: > On Tue, Dec 19, 2017 at 1:57 AM, Kees Cook <keesc...@chromium.org> wrote: > > On Mon, Dec 18, 2017 at 6:22 AM, Tetsuo Handa > > <penguin-ker...@i-love.sakura.ne.jp> wrote: > >> On 2017/12/18 22:40, syzbot wrote: > >>> Hello, > >>> > >>> syzkaller hit the following crash on > >>> 6084b576dca2e898f5c101baef151f7bfdbb606d > >>> git://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git/master > >>> compiler: gcc (GCC) 7.1.1 20170620 > >>> .config is attached > >>> Raw console output is attached. > >>> > >>> Unfortunately, I don't have any reproducer for this bug yet. > >>> > >>> > >> > >> This BUG is reporting > >> > >> [ 26.089789] usercopy: kernel memory overwrite attempt detected to > >> 0000000022a5b430 (kmalloc-1024) (1024 bytes) > >> > >> line. But isn't 0000000022a5b430 strange for kmalloc(1024, GFP_KERNEL)ed > >> kernel address? > > > > The address is hashed (see the %p threads for 4.15). > > > +Tobin, is there a way to disable hashing entirely? The only > designation of syzbot is providing crash reports to kernel developers > with as much info as possible. It's fine for it to leak whatever.
We have new specifier %px to print addresses in hex if leaking info is not a worry. Hope this helps, Tobin.
