Merge commit 'v3.5-rc2' into next

1 files changed, 21 insertions, 0 deletions

diff --git a/kernel/capability.c b/kernel/capability.c
index 3f1adb6c6470..493d97259484 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -419,3 +419,24 @@ bool nsown_capable(int cap)
 {
 	return ns_capable(current_user_ns(), cap);
 }
+
+/**
+ * inode_capable - Check superior capability over inode
+ * @inode: The inode in question
+ * @cap: The capability in question
+ *
+ * Return true if the current task has the given superior capability
+ * targeted at it's own user namespace and that the given inode is owned
+ * by the current user namespace or a child namespace.
+ *
+ * Currently we check to see if an inode is owned by the current
+ * user namespace by seeing if the inode's owner maps into the
+ * current user namespace.
+ *
+ */
+bool inode_capable(const struct inode *inode, int cap)
+{
+	struct user_namespace *ns = current_user_ns();
+
+	return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid);
+}