From: Greg Kroah-Hartman Date: Wed, 6 Dec 2017 09:50:08 +0000 (+0000) Subject: efi: Move some sysfs files to be read-only by root X-Git-Tag: v3.18.88~54 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=25ea12ec0370ad88d356e84bca5a2a0f65b1bac6;p=thirdparty%2Fkernel%2Fstable.git efi: Move some sysfs files to be read-only by root 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 Tested-by: Dave Young Signed-off-by: Greg Kroah-Hartman Signed-off-by: Ard Biesheuvel Cc: H. Peter Anvin Cc: Matt Fleming Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: linux-efi@vger.kernel.org Link: http://lkml.kernel.org/r/20171206095010.24170-2-ard.biesheuvel@linaro.org Signed-off-by: Ingo Molnar Signed-off-by: Greg Kroah-Hartman --- diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c index 71e090c8c85e7..297066df69462 100644 --- a/drivers/firmware/efi/efi.c +++ b/drivers/firmware/efi/efi.c @@ -96,8 +96,7 @@ static ssize_t systab_show(struct kobject *kobj, 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 diff --git a/drivers/firmware/efi/runtime-map.c b/drivers/firmware/efi/runtime-map.c index 87b8e3b900d21..1df70fd4787f7 100644 --- 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 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_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. diff --git a/include/linux/sysfs.h b/include/linux/sysfs.h index f97d0dbb59fac..70ceb2a14a57f 100644 --- 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, \