[PATCH] Rework of IPC auditing
1) The audit_ipc_perms() function has been split into two different
functions:
- audit_ipc_obj()
- audit_ipc_set_perm()
There's a key shift here... The audit_ipc_obj() collects the uid, gid,
mode, and SElinux context label of the current ipc object. This
audit_ipc_obj() hook is now found in several places. Most notably, it
is hooked in ipcperms(), which is called in various places around the
ipc code permforming a MAC check. Additionally there are several places
where *checkid() is used to validate that an operation is being
performed on a valid object while not necessarily having a nearby
ipcperms() call. In these locations, audit_ipc_obj() is called to
ensure that the information is captured by the audit system.
The audit_set_new_perm() function is called any time the permissions on
the ipc object changes. In this case, the NEW permissions are recorded
(and note that an audit_ipc_obj() call exists just a few lines before
each instance).
2) Support for an AUDIT_IPC_SET_PERM audit message type. This allows
for separate auxiliary audit records for normal operations on an IPC
object and permissions changes. Note that the same struct
audit_aux_data_ipcctl is used and populated, however there are separate
audit_log_format statements based on the type of the message. Finally,
the AUDIT_IPC block of code in audit_free_aux() was extended to handle
aux messages of this new type. No more mem leaks I hope ;-)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/ipc/msg.c b/ipc/msg.c
index 48a7f17..7d1340c 100644
--- a/ipc/msg.c
+++ b/ipc/msg.c
@@ -13,6 +13,9 @@
* mostly rewritten, threaded and wake-one semantics added
* MSGMAX limit removed, sysctl's added
* (c) 1999 Manfred Spraul <manfred@colorfullife.com>
+ *
+ * support for audit of ipc object properties and permission changes
+ * Dustin Kirkland <dustin.kirkland@us.ibm.com>
*/
#include <linux/capability.h>
@@ -447,6 +450,11 @@
if (msg_checkid(msq,msqid))
goto out_unlock_up;
ipcp = &msq->q_perm;
+
+ err = audit_ipc_obj(ipcp);
+ if (err)
+ goto out_unlock_up;
+
err = -EPERM;
if (current->euid != ipcp->cuid &&
current->euid != ipcp->uid && !capable(CAP_SYS_ADMIN))
@@ -460,7 +468,8 @@
switch (cmd) {
case IPC_SET:
{
- if ((err = audit_ipc_perms(setbuf.qbytes, setbuf.uid, setbuf.gid, setbuf.mode, ipcp)))
+ err = audit_ipc_set_perm(setbuf.qbytes, setbuf.uid, setbuf.gid, setbuf.mode, ipcp);
+ if (err)
goto out_unlock_up;
err = -EPERM;