On Tue, Apr 16, 2019 at 10:19:42PM +0200, Arnd Bergmann wrote: > +#ifdef CONFIG_COMPAT > +struct ppp_option_data32 { > + compat_caddr_t ptr; Huh? compat_uptr_t, surely? I realize that compat_ioctl.c is bogus that way right now, but let's not spread that crap into the places where it's harder to find... > err = -EFAULT; > - if (copy_from_user(&data, (void __user *) arg, sizeof(data))) > - goto out; > +#ifdef CONFIG_COMPAT > + if (compat) { > + struct ppp_option_data32 data32; > + > + if (copy_from_user(&data32, (void __user *) arg, > + sizeof(data32))) > + goto out; > + > + data.ptr = compat_ptr(data32.ptr); > + data.length = data32.length; > + data.transmit = data32.transmit; > + } else > +#endif > + { > + if (copy_from_user(&data, (void __user *) arg, sizeof(data))) > + goto out; > + } *UGH* Do that in caller, please. And sod the flag argument...