On Tue, Dec 19, 2017 at 10:04 AM, Tobin C. Harding <me@xxxxxxxx> wrote: >> >> > <penguin-kernel@xxxxxxxxxxxxxxxxxxx> 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. >> >> This is not a per-printf-site thing. It's per-machine thing. > > There is no way to disable the hashing currently built into the system. Ack. Any kind of continuous testing systems would be a use case for this. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
