Re: [PATCH 3/3] audit: drop audit_cmd_lock in AUDIT_USER family of cases

We do not need to hold the audit_cmd_mutex for this family of cases. The possible exception to this is the call to audit_filter_user(), so drop the lock immediately after. To help in fixing the race we are trying to avoid, make sure that nothing called by audit_filter_user() calls audit_log_start(). In particular, watch out for *_audit_rule_match(). This fix will take care of systemd and anything USING audit. It still means that we could race with something configuring audit and auditd shutting down. Signed-off-by: Richard Guy Briggs <rgb(a)tricolour.ca&gt; Signed-off-by: Richard Guy Briggs <rgb(a)redhat.com&gt;

--- kernel/audit.c | 2 ++ 1 files changed, 2 insertions(+), 0 deletions(-) diff --git a/kernel/audit.c b/kernel/audit.c index 4689012..4cbc945 100644 --- a/kernel/audit.c +++ b/kernel/audit.c @@ -713,6 +713,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) if (err) break; } + mutex_unlock(&audit_cmd_mutex); audit_log_common_recv_msg(&ab, msg_type); if (msg_type != AUDIT_USER_TTY) audit_log_format(ab, " msg='%.1024s'", @@ -729,6 +730,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh) } audit_set_pid(ab, NETLINK_CB(skb).portid); audit_log_end(ab); + mutex_lock(&audit_cmd_mutex); } break; case AUDIT_ADD_RULE: -- 1.7.1