locks: Don't allow mounts in user namespaces to enable mandatory locking

Since no one uses mandatory locking and files with mandatory locks can
cause problems don't allow them in user namespaces.

Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Jeff Layton <jeff.layton@primarydata.com>

diff --git a/fs/namespace.c b/fs/namespace.c
index 4219885e9681124747f1266c402c219e0ce05918..4d2c8f64b7bf03e4ca0817bcfa1c51a11c8891cb 100644 (file)
--- a/fs/namespace.c
+++ b/fs/namespace.c
@@ -1589,7 +1589,7 @@ static inline bool may_mandlock(void)
 #ifndef        CONFIG_MANDATORY_FILE_LOCKING
        return false;
 #endif
-       return true;
+       return capable(CAP_SYS_ADMIN);
 }
 
 /*