[PATCH 2/3] libnvdimm, namespace: make 'resource' attribute only readable by root

From: Dan Williams
Date: Tue Sep 26 2017 - 19:04:08 EST


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")
Cc: <stable@xxxxxxxxxxxxxxx>
Reported-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
drivers/nvdimm/namespace_devs.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/nvdimm/namespace_devs.c b/drivers/nvdimm/namespace_devs.c
index 3e4d1e7998da..0af988739a06 100644
--- a/drivers/nvdimm/namespace_devs.c
+++ b/drivers/nvdimm/namespace_devs.c
@@ -1620,7 +1620,7 @@ static umode_t namespace_visible(struct kobject *kobj,
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)) {