[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>
This commit is contained in:
Steve Grubb
2006-04-02 17:07:33 -04:00
committed by Al Viro
parent ce29b682e2
commit 073115d6b2
6 changed files with 98 additions and 11 deletions

View File

@ -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 @@ asmlinkage long sys_msgctl (int msqid, int cmd, struct msqid_ds __user *buf)
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 @@ asmlinkage long sys_msgctl (int msqid, int cmd, struct msqid_ds __user *buf)
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;