[3.5.y.z extended stable] Patch "audit: printk USER_AVC messages when audit isn't enabled" has been added to staging queue

[Luis Henriques]

This is a note to let you know that I have just added a patch titled

    audit: printk USER_AVC messages when audit isn't enabled

to the linux-3.5.y-queue branch of the 3.5.y.z extended stable tree 
which can be found at:

 http://kernel.ubuntu.com/git?p=ubuntu/linux.git;a=shortlog;h=refs/heads/linux-3.5.y-queue

If you, or anyone else, feels it should not be added to this tree, please 
reply to this email.

For more information about the 3.5.y.z tree, see
https://wiki.ubuntu.com/Kernel/Dev/ExtendedStable

Thanks.
-Luis

------

>From bd4bba2750d68bb460f4a85a781aa36dbdb5491e Mon Sep 17 00:00:00 2001
From: Tyler Hicks <tyhicks at canonical.com>
Date: Thu, 25 Jul 2013 18:02:55 -0700
Subject: audit: printk USER_AVC messages when audit isn't enabled

commit 0868a5e150bc4c47e7a003367cd755811eb41e0b upstream.

When the audit=1 kernel parameter is absent and auditd is not running,
AUDIT_USER_AVC messages are being silently discarded.

AUDIT_USER_AVC messages should be sent to userspace using printk(), as
mentioned in the commit message of 4a4cd633 ("AUDIT: Optimise the
audit-disabled case for discarding user messages").

When audit_enabled is 0, audit_receive_msg() discards all user messages
except for AUDIT_USER_AVC messages. However, audit_log_common_recv_msg()
refuses to allocate an audit_buffer if audit_enabled is 0. The fix is to
special case AUDIT_USER_AVC messages in both functions.

It looks like commit 50397bd1 ("[AUDIT] clean up audit_receive_msg()")
introduced this bug.

Signed-off-by: Tyler Hicks <tyhicks at canonical.com>
Cc: Al Viro <viro at zeniv.linux.org.uk>
Cc: Eric Paris <eparis at redhat.com>
Cc: linux-audit at redhat.com
Acked-by: Kees Cook <keescook at chromium.org>
Signed-off-by: Richard Guy Briggs <rgb at redhat.com>
Signed-off-by: Eric Paris <eparis at redhat.com>
[ luis: backported to 3.5: adjusted context ]
Signed-off-by: Luis Henriques <luis.henriques at canonical.com>
---
 kernel/audit.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 5917dfe..f02d3fc 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -625,7 +625,7 @@ static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
 	char *ctx = NULL;
 	u32 len;

-	if (!audit_enabled) {
+	if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
 		*ab = NULL;
 		return rc;
 	}
--
1.8.3.2