[PATCH] keys: add a way to store the appropriate context for newly-created keys

Add a /proc/<pid>/attr/keycreate entry that stores the appropriate context for
newly-created keys.  Modify the selinux_key_alloc hook to make use of the new
entry.  Update the flask headers to include a new "setkeycreate" permission
for processes.  Update the flask headers to include a new "create" permission
for keys.  Use the create permission to restrict which SIDs each task can
assign to newly-created keys.  Add a new parameter to the security hook
"security_key_alloc" to indicate whether it is being invoked by the kernel, or
from userspace.  If it is being invoked by the kernel, the security hook
should never fail.  Update the documentation 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, 6 insertions, 0 deletions

diff --git a/fs/proc/base.c b/fs/proc/base.c
index 6afff725a8c9..c4a1ff371b8d 100644
--- a/fs/proc/base.c
+++ b/fs/proc/base.c
@@ -121,6 +121,7 @@ enum pid_directory_inos {
         PROC_TGID_ATTR_PREV,
         PROC_TGID_ATTR_EXEC,
         PROC_TGID_ATTR_FSCREATE,
+        PROC_TGID_ATTR_KEYCREATE,
 #endif
 #ifdef CONFIG_AUDITSYSCALL
         PROC_TGID_LOGINUID,
@@ -162,6 +163,7 @@ enum pid_directory_inos {
         PROC_TID_ATTR_PREV,
         PROC_TID_ATTR_EXEC,
         PROC_TID_ATTR_FSCREATE,
+        PROC_TID_ATTR_KEYCREATE,
 #endif
 #ifdef CONFIG_AUDITSYSCALL
         PROC_TID_LOGINUID,
@@ -275,6 +277,7 @@ static struct pid_entry tgid_attr_stuff[] = {
         E(PROC_TGID_ATTR_PREV,     "prev",     S_IFREG|S_IRUGO),
         E(PROC_TGID_ATTR_EXEC,     "exec",     S_IFREG|S_IRUGO|S_IWUGO),
         E(PROC_TGID_ATTR_FSCREATE, "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
+        E(PROC_TGID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
         {0,0,NULL,0}
 };
 static struct pid_entry tid_attr_stuff[] = {
@@ -282,6 +285,7 @@ static struct pid_entry tid_attr_stuff[] = {
         E(PROC_TID_ATTR_PREV,      "prev",     S_IFREG|S_IRUGO),
         E(PROC_TID_ATTR_EXEC,      "exec",     S_IFREG|S_IRUGO|S_IWUGO),
         E(PROC_TID_ATTR_FSCREATE,  "fscreate", S_IFREG|S_IRUGO|S_IWUGO),
+        E(PROC_TID_ATTR_KEYCREATE, "keycreate", S_IFREG|S_IRUGO|S_IWUGO),
         {0,0,NULL,0}
 };
 #endif
@@ -1801,6 +1805,8 @@ static struct dentry *proc_pident_lookup(struct inode *dir,
                 case PROC_TGID_ATTR_EXEC:
                 case PROC_TID_ATTR_FSCREATE:
                 case PROC_TGID_ATTR_FSCREATE:
+                case PROC_TID_ATTR_KEYCREATE:
+                case PROC_TGID_ATTR_KEYCREATE:
                         inode->i_fop = &proc_pid_attr_operations;
                         break;
 #endif