3.18-stable review patch. If anyone has any objections, please let me know.
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From: Greg Kroah-Hartman gregkh@linuxfoundation.org
commit af97a77bc01ce49a466f9d4c0125479e2e2230b6 upstream.
Thanks to the scripts/leaking_addresses.pl script, it was found that some EFI values should not be readable by non-root users.
So make them root-only, and to do that, add a __ATTR_RO_MODE() macro to make this easier, and use it in other places at the same time.
Reported-by: Linus Torvalds torvalds@linux-foundation.org Tested-by: Dave Young dyoung@redhat.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Ard Biesheuvel ard.biesheuvel@linaro.org Cc: H. Peter Anvin hpa@zytor.com Cc: Matt Fleming matt@codeblueprint.co.uk Cc: Peter Zijlstra peterz@infradead.org Cc: Thomas Gleixner tglx@linutronix.de Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20171206095010.24170-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar mingo@kernel.org Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/firmware/efi/efi.c | 3 +-- drivers/firmware/efi/runtime-map.c | 10 +++++----- include/linux/sysfs.h | 6 ++++++ 3 files changed, 12 insertions(+), 7 deletions(-)
--- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -96,8 +96,7 @@ static ssize_t systab_show(struct kobjec return str - buf; }
-static struct kobj_attribute efi_attr_systab = - __ATTR(systab, 0400, systab_show, NULL); +static struct kobj_attribute efi_attr_systab = __ATTR_RO_MODE(systab, 0400);
#define EFI_FIELD(var) efi.var
--- a/drivers/firmware/efi/runtime-map.c +++ b/drivers/firmware/efi/runtime-map.c @@ -67,11 +67,11 @@ static ssize_t map_attr_show(struct kobj 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_RO_MODE(type, 0400); +static struct map_attribute map_phys_addr_attr = __ATTR_RO_MODE(phys_addr, 0400); +static struct map_attribute map_virt_addr_attr = __ATTR_RO_MODE(virt_addr, 0400); +static struct map_attribute map_num_pages_attr = __ATTR_RO_MODE(num_pages, 0400); +static struct map_attribute map_attribute_attr = __ATTR_RO_MODE(attribute, 0400);
/* * These are default attributes that are added for every memmap entry. --- a/include/linux/sysfs.h +++ b/include/linux/sysfs.h @@ -82,6 +82,12 @@ struct attribute_group { .show = _name##_show, \ }
+#define __ATTR_RO_MODE(_name, _mode) { \ + .attr = { .name = __stringify(_name), \ + .mode = VERIFY_OCTAL_PERMISSIONS(_mode) }, \ + .show = _name##_show, \ +} + #define __ATTR_WO(_name) { \ .attr = { .name = __stringify(_name), .mode = S_IWUSR }, \ .store = _name##_store, \