[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, 7 insertions, 0 deletions

diff --git a/security/keys/proc.c b/security/keys/proc.c
index 12b750e51fbf..686a9ee0c5de 100644
--- a/security/keys/proc.c
+++ b/security/keys/proc.c
@@ -137,6 +137,13 @@ static int proc_keys_show(struct seq_file *m, void *v)
         struct timespec now;
         unsigned long timo;
         char xbuf[12];
+        int rc;
+
+        /* check whether the current task is allowed to view the key (assuming
+         * non-possession) */
+        rc = key_task_permission(make_key_ref(key, 0), current, KEY_VIEW);
+        if (rc < 0)
+                return 0;
 
         now = current_kernel_time();