On Wed, Jan 10, 2018 at 7:25 AM, Christopher Lameter <cl@xxxxxxxxx> wrote: > On Tue, 9 Jan 2018, Kees Cook wrote: > >> -static void report_usercopy(unsigned long len, bool to_user, const char *type) >> +int report_usercopy(const char *name, const char *detail, bool to_user, >> + unsigned long offset, unsigned long len) >> { >> - pr_emerg("kernel memory %s attempt detected %s '%s' (%lu bytes)\n", >> + pr_emerg("kernel memory %s attempt detected %s %s%s%s%s (offset %lu, size %lu)\n", >> to_user ? "exposure" : "overwrite", >> - to_user ? "from" : "to", type ? : "unknown", len); >> + to_user ? "from" : "to", >> + name ? : "unknown?!", >> + detail ? " '" : "", detail ? : "", detail ? "'" : "", >> + offset, len); >> /* >> * For greater effect, it would be nice to do do_group_exit(), >> * but BUG() actually hooks all the lock-breaking and per-arch >> * Oops code, so that is used here instead. >> */ >> BUG(); > > Should this be a WARN() or so? Or some configuration that changes > BUG() behavior? Otherwise This BUG() is the existing behavior, with the new behavior taking the WARN() route in a following patch. >> + >> + return -1; > > This return code will never be returned. > > Why a return code at all? Maybe I will see that in the following patches? I was trying to simplify the callers, but I agree, the result is rather ugly. I'll see if I can fix this up. -Kees -- Kees Cook Pixel Security