From de5109898a8a0cb001abcb6916bef4efa32bf39b Mon Sep 17 00:00:00 2001
From: Rusty Russell <rusty@rustcorp.com.au>
Date: Wed, 14 May 2014 10:33:50 +0930
Subject: [PATCH] samples/kobject/: avoid world-writable sysfs files.

In line with practice for module parameters, we're adding a build-time
check that sysfs files aren't world-writable.

Cc: Greg Kroah-Hartman <greg@kroah.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
---
 samples/kobject/kobject-example.c | 7 ++++---
 samples/kobject/kset-example.c    | 7 ++++---
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/samples/kobject/kobject-example.c b/samples/kobject/kobject-example.c
index 86ea0c3ad97511..01562e0d499202 100644
--- a/samples/kobject/kobject-example.c
+++ b/samples/kobject/kobject-example.c
@@ -40,8 +40,9 @@ static ssize_t foo_store(struct kobject *kobj, struct kobj_attribute *attr,
 	return count;
 }
 
+/* Sysfs attributes cannot be world-writable. */
 static struct kobj_attribute foo_attribute =
-	__ATTR(foo, 0666, foo_show, foo_store);
+	__ATTR(foo, 0664, foo_show, foo_store);
 
 /*
  * More complex function where we determine which variable is being accessed by
@@ -73,9 +74,9 @@ static ssize_t b_store(struct kobject *kobj, struct kobj_attribute *attr,
 }
 
 static struct kobj_attribute baz_attribute =
-	__ATTR(baz, 0666, b_show, b_store);
+	__ATTR(baz, 0664, b_show, b_store);
 static struct kobj_attribute bar_attribute =
-	__ATTR(bar, 0666, b_show, b_store);
+	__ATTR(bar, 0664, b_show, b_store);
 
 
 /*
diff --git a/samples/kobject/kset-example.c b/samples/kobject/kset-example.c
index 5dce351f131f8c..ab5e447ec23871 100644
--- a/samples/kobject/kset-example.c
+++ b/samples/kobject/kset-example.c
@@ -124,8 +124,9 @@ static ssize_t foo_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
 	return count;
 }
 
+/* Sysfs attributes cannot be world-writable. */
 static struct foo_attribute foo_attribute =
-	__ATTR(foo, 0666, foo_show, foo_store);
+	__ATTR(foo, 0664, foo_show, foo_store);
 
 /*
  * More complex function where we determine which variable is being accessed by
@@ -157,9 +158,9 @@ static ssize_t b_store(struct foo_obj *foo_obj, struct foo_attribute *attr,
 }
 
 static struct foo_attribute baz_attribute =
-	__ATTR(baz, 0666, b_show, b_store);
+	__ATTR(baz, 0664, b_show, b_store);
 static struct foo_attribute bar_attribute =
-	__ATTR(bar, 0666, b_show, b_store);
+	__ATTR(bar, 0664, b_show, b_store);
 
 /*
  * Create a group of attributes so that we can create and destroy them all
-- 
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