[PATCH 4.4 48/96] libnvdimm, namespace: make resource attribute only readable by root

Greg Kroah-Hartman
2017-11-28T10:29:34Z

From: Dan Williams <dan.j.williams@intel.com>

commit c1fb3542074fd0c4d901d778bd52455111e4eb6f upstream.

For the same reason that /proc/iomem returns 0's for non-root readers
and acpi tables are root-only, make the 'resource' attribute for
namespace devices only readable by root. Otherwise we disclose physical
address information.

Fixes: bf9bccc14c05 ("libnvdimm: pmem label sets and namespace instantiation")
Reported-by: Dave Hansen <dave.hansen@linux.intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/nvdimm/namespace_devs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1305,7 +1305,7 @@ static umode_t namespace_visible(struct
if (a == &dev_attr_resource.attr) {
if (is_namespace_blk(dev))
return 0;
- return a->mode;
+ return 0400;
}

if (is_namespace_pmem(dev) || is_namespace_blk(dev)) {