[PATCH] Revert "AUDIT: Allow login in non-init namespaces"

From: Calvin Owens
Date: Tue Nov 04 2014 - 19:46:57 EST


This reverts 543bc6a1a987 "AUDIT: Allow login in non-init namespaces".

This commit incorrectly assumes that libpam treats -ECONNREFUSED as
an indicator that audit is disabled, and -EPERM or any other error
as a fatal error that prevents the login from continuing.

The opposite is in fact true: -EPERM allows the login to continue,
and -ECONNREFUSED causes it to refuse the login. This behavior has
been unchanged in upstream linux-pam since at least 2008.

Reverting this change allows libpam to again work as expected in
non-init user namespaces.

Signed-off-by: Calvin Owens <calvinowens@xxxxxx>
Cc: stable@xxxxxxxxxxxxxxx
---
Relevant code in linux-pam:
https://git.fedorahosted.org/cgit/linux-pam.git/tree/libpam/pam_audit.c#n56

kernel/audit.c | 12 +-----------
1 file changed, 1 insertion(+), 11 deletions(-)

diff --git a/kernel/audit.c b/kernel/audit.c
index 80983df..656e8ce 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -640,18 +640,8 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
int err = 0;

/* Only support initial user namespace for now. */
- /*
- * We return ECONNREFUSED because it tricks userspace into thinking
- * that audit was not configured into the kernel. Lots of users
- * configure their PAM stack (because that's what the distro does)
- * to reject login if unable to send messages to audit. If we return
- * ECONNREFUSED the PAM stack thinks the kernel does not have audit
- * configured in and will let login proceed. If we return EPERM
- * userspace will reject all logins. This should be removed when we
- * support non init namespaces!!
- */
if (current_user_ns() != &init_user_ns)
- return -ECONNREFUSED;
+ return -EPERM;

switch (msg_type) {
case AUDIT_LIST:
--
2.1.1

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/