[PATCH 31/43] userns: Teach inode_capable to understand inodes whose uids map to other namespaces.

[\"Eric W. Beiderman]

From: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>

Signed-off-by: Eric W. Biederman <ebiederm@xxxxxxxxxxxx>
---
 kernel/capability.c |    6 ++++--
 1 files changed, 4 insertions(+), 2 deletions(-)

diff --git a/kernel/capability.c b/kernel/capability.c
index cc5f071..493d972 100644
--- a/kernel/capability.c
+++ b/kernel/capability.c
@@ -429,12 +429,14 @@ bool nsown_capable(int cap)
  * targeted at it's own user namespace and that the given inode is owned
  * by the current user namespace or a child namespace.
  *
- * Currently inodes can only be owned by the initial user 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) && (ns == &init_user_ns);
+	return ns_capable(ns, cap) && kuid_has_mapping(ns, inode->i_uid);
 }
-- 
1.7.2.5

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