audit: printk USER_AVC messages when audit isn't enabled

BugLink: http://bugs.launchpad.net/bugs/1473584

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.

Cc: <stable@kernel.org> # v2.6.25+
Signed-off-by: Tyler Hicks <tyhicks@canonical.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Eric Paris <eparis@redhat.com>
Cc: linux-audit@redhat.com
Acked-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Guy Briggs <rgb@redhat.com>
Signed-off-by: Eric Paris <eparis@redhat.com>
(cherry picked from commit 0868a5e150bc4c47e7a003367cd755811eb41e0b)
Signed-off-by: Tim Gardner <tim.gardner@canonical.com>
This commit is contained in:
Tyler Hicks
2013-07-25 18:02:55 -07:00
committed by Tim Gardner
parent dc24e8522f
commit f95d736274

View File

@@ -625,7 +625,7 @@ static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
char *ctx = NULL; char *ctx = NULL;
u32 len; u32 len;
if (!audit_enabled) { if (!audit_enabled && msg_type != AUDIT_USER_AVC) {
*ab = NULL; *ab = NULL;
return rc; return rc;
} }