On Wed, Nov 29, 2017 at 01:36:25PM -0800, Linus Torvalds wrote: > On Wed, Nov 29, 2017 at 1:14 PM, Linus Torvalds > <torvalds@xxxxxxxxxxxxxxxxxxxx> wrote: > > > > Not because %pK itself changed, but because the semantics of %p did. > > The baseline moved, and the "safe" version did not. > > Btw, that baseline for me is now that I can do > > ./scripts/leaking_addresses.pl | wc -l > 18 > > and of those 18 hits, six are false positives (looks like bitmaps in > the uevent keys). > > The remaining 12 are from the EFI runtime map files > (/sys/firmware/efi/runtime-map/*). They should presumably not be > world-readable, but sadly the kset_create_and_add() helper seems to do > that by default. > > I think the sysfs code makes it insanely too easy to make things > world-readable. You try to be careful, and mark things read-only etc, > but __ATTR_RO() jkust means S_IRUGO, which means world-readable. > > There seems to be no convenient model for kobjects having better > permissions. Greg? They can just use __ATTR() which lets you set the exact mode settings that are wanted. Something like the patch below, which breaks the build as the map_attributes are "odd", but you get the idea. The EFI developers can fix this up properly :) Note, this only accounts for 5 attributes, what is the whole list? thanks, greg k-h diff --git a/drivers/firmware/efi/runtime-map.c b/drivers/firmware/efi/runtime-map.c index 8e64b77aeac9..09444964c8d7 100644 --- a/drivers/firmware/efi/runtime-map.c +++ b/drivers/firmware/efi/runtime-map.c @@ -63,11 +63,11 @@ static ssize_t map_attr_show(struct kobject *kobj, struct attribute *attr, return map_attr->show(entry, buf); } -static struct map_attribute map_type_attr = __ATTR_RO(type); -static struct map_attribute map_phys_addr_attr = __ATTR_RO(phys_addr); -static struct map_attribute map_virt_addr_attr = __ATTR_RO(virt_addr); -static struct map_attribute map_num_pages_attr = __ATTR_RO(num_pages); -static struct map_attribute map_attribute_attr = __ATTR_RO(attribute); +static struct map_attribute map_type_attr = __ATTR(type, 0400, type_show, NULL); +static struct map_attribute map_phys_addr_attr = __ATTR(phys_addr, 0400, phys_addr_show, NULL); +static struct map_attribute map_virt_addr_attr = __ATTR(virt_addr, 0400, virt_addr_show, NULL); +static struct map_attribute map_num_pages_attr = __ATTR(num_pages, 0400, num_pages_show, NULL); +static struct map_attribute map_attribute_attr = __ATTR(attribute, 0400, attribute_show, NULL); /* * These are default attributes that are added for every memmap entry. -- To unsubscribe from this list: send the line "unsubscribe linux-efi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
