[PATCH] keys: restrict contents of /proc/keys to Viewable keys

Restrict /proc/keys such that only those keys to which the current task is
granted View permission are presented.

The documentation is also updated to reflect these changes.

Signed-off-by: Michael LeMay <mdlemay@epoch.ncsc.mil>
Signed-off-by: James Morris <jmorris@namei.org>
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 13 insertions, 7 deletions

diff --git a/security/Kconfig b/security/Kconfig
index 34f593410d5..67785df264e 100644
--- a/security/Kconfig
+++ b/security/Kconfig
@@ -22,16 +22,22 @@ config KEYS
           If you are unsure as to whether this is required, answer N.
 
 config KEYS_DEBUG_PROC_KEYS
-        bool "Enable the /proc/keys file by which all keys may be viewed"
+        bool "Enable the /proc/keys file by which keys may be viewed"
         depends on KEYS
         help
-          This option turns on support for the /proc/keys file through which
-          all the keys on the system can be listed.
+          This option turns on support for the /proc/keys file - through which
+          can be listed all the keys on the system that are viewable by the
+          reading process.
 
-          This option is a slight security risk in that it makes it possible
-          for anyone to see all the keys on the system. Normally the manager
-          pretends keys that are inaccessible to a process don't exist as far
-          as that process is concerned.
+          The only keys included in the list are those that grant View
+          permission to the reading process whether or not it possesses them.
+          Note that LSM security checks are still performed, and may further
+          filter out keys that the current process is not authorised to view.
+
+          Only key attributes are listed here; key payloads are not included in
+          the resulting table.
+
+          If you are unsure as to whether this is required, answer N.
 
 config SECURITY
         bool "Enable different security models"