[PATCH 4.13 15/52] thunderbolt: Make key root-only accessible

From: Greg Kroah-Hartman
Date: Mon Sep 18 2017 - 05:10:29 EST

4.13-stable review patch. If anyone has any objections, please let me know.


From: Bernat, Yehezkel <yehezkel.bernat@xxxxxxxxx>

commit 0956e41169222822d3557871fcd1d32e4fa7e934 upstream.

Non-root user may read the key back after root wrote it there.
This removes read access to everyone but root.

Signed-off-by: Yehezkel Bernat <yehezkel.bernat@xxxxxxxxx>
Acked-by: Mika Westerberg <mika.westerberg@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

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

--- a/drivers/thunderbolt/switch.c
+++ b/drivers/thunderbolt/switch.c
@@ -826,7 +826,7 @@ static ssize_t key_store(struct device *
return ret;
-static DEVICE_ATTR_RW(key);
+static DEVICE_ATTR(key, 0600, key_show, key_store);

static ssize_t nvm_authenticate_show(struct device *dev,
struct device_attribute *attr, char *buf)