X-Git-Url: https://err.no/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=security%2Fdevice_cgroup.c;h=fd764a0858d0d5f1f60f1b671cbcc41c04be77dd;hb=aafcd2f7d6790490bd921f04390bc210b386ecfa;hp=4ea583689eec0ae6cdb638d7ed025f25e9bac025;hpb=c15a2434ed4868cad99278ac4d4ae4de9de62e02;p=linux-2.6

diff --git a/security/device_cgroup.c b/security/device_cgroup.c
index 4ea583689e..fd764a0858 100644
--- a/security/device_cgroup.c
+++ b/security/device_cgroup.c
@@ -49,10 +49,14 @@ struct dev_cgroup {
 	spinlock_t lock;
 };
 
+static inline struct dev_cgroup *css_to_devcgroup(struct cgroup_subsys_state *s)
+{
+	return container_of(s, struct dev_cgroup, css);
+}
+
 static inline struct dev_cgroup *cgroup_to_devcgroup(struct cgroup *cgroup)
 {
-	return container_of(cgroup_subsys_state(cgroup, devices_subsys_id),
-			    struct dev_cgroup, css);
+	return css_to_devcgroup(cgroup_subsys_state(cgroup, devices_subsys_id));
 }
 
 struct cgroup_subsys devices_subsys;
@@ -102,7 +106,7 @@ free_and_exit:
 static int dev_whitelist_add(struct dev_cgroup *dev_cgroup,
 			struct dev_whitelist_item *wh)
 {
-	struct dev_whitelist_item *whcopy;
+	struct dev_whitelist_item *whcopy, *walk;
 
 	whcopy = kmalloc(sizeof(*whcopy), GFP_KERNEL);
 	if (!whcopy)
@@ -110,7 +114,21 @@ static int dev_whitelist_add(struct dev_cgroup *dev_cgroup,
 
 	memcpy(whcopy, wh, sizeof(*whcopy));
 	spin_lock(&dev_cgroup->lock);
-	list_add_tail(&whcopy->list, &dev_cgroup->whitelist);
+	list_for_each_entry(walk, &dev_cgroup->whitelist, list) {
+		if (walk->type != wh->type)
+			continue;
+		if (walk->major != wh->major)
+			continue;
+		if (walk->minor != wh->minor)
+			continue;
+
+		walk->access |= wh->access;
+		kfree(whcopy);
+		whcopy = NULL;
+	}
+
+	if (whcopy != NULL)
+		list_add_tail(&whcopy->list, &dev_cgroup->whitelist);
 	spin_unlock(&dev_cgroup->lock);
 	return 0;
 }
@@ -364,6 +382,8 @@ static ssize_t devcgroup_access_write(struct cgroup *cgroup, struct cftype *cft,
 	case 'a':
 		wh.type = DEV_ALL;
 		wh.access = ACC_MASK;
+		wh.major = ~0;
+		wh.minor = ~0;
 		goto handle;
 	case 'b':
 		wh.type = DEV_BLOCK;
@@ -502,7 +522,6 @@ struct cgroup_subsys devices_subsys = {
 
 int devcgroup_inode_permission(struct inode *inode, int mask)
 {
-	struct cgroup *cgroup;
 	struct dev_cgroup *dev_cgroup;
 	struct dev_whitelist_item *wh;
 
@@ -511,8 +530,8 @@ int devcgroup_inode_permission(struct inode *inode, int mask)
 		return 0;
 	if (!S_ISBLK(inode->i_mode) && !S_ISCHR(inode->i_mode))
 		return 0;
-	cgroup = task_cgroup(current, devices_subsys.subsys_id);
-	dev_cgroup = cgroup_to_devcgroup(cgroup);
+	dev_cgroup = css_to_devcgroup(task_subsys_state(current,
+				devices_subsys_id));
 	if (!dev_cgroup)
 		return 0;
 
@@ -543,12 +562,11 @@ acc_check:
 
 int devcgroup_inode_mknod(int mode, dev_t dev)
 {
-	struct cgroup *cgroup;
 	struct dev_cgroup *dev_cgroup;
 	struct dev_whitelist_item *wh;
 
-	cgroup = task_cgroup(current, devices_subsys.subsys_id);
-	dev_cgroup = cgroup_to_devcgroup(cgroup);
+	dev_cgroup = css_to_devcgroup(task_subsys_state(current,
+				devices_subsys_id));
 	if (!dev_cgroup)
 		return 0;