Add audit uid to netlink credentials

Most audit control messages are sent over netlink.In order to properly
log the identity of the sender of audit control messages, we would like
to add the loginuid to the netlink_creds structure, as per the attached
patch.

Signed-off-by: Serge Hallyn <serue@us.ibm.com>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>

2 files changed, 29 insertions, 22 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index 58c7d7e47299..587d3b2eba7f 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -239,36 +239,36 @@ void audit_log_lost(const char *message)
 
 }
 
-static int audit_set_rate_limit(int limit)
+static int audit_set_rate_limit(int limit, uid_t loginuid)
 {
         int old          = audit_rate_limit;
         audit_rate_limit = limit;
-        audit_log(current->audit_context, "audit_rate_limit=%d old=%d",
-                  audit_rate_limit, old);
+        audit_log(NULL, "audit_rate_limit=%d old=%d by auid %u",
+                        audit_rate_limit, old, loginuid);
         return old;
 }
 
-static int audit_set_backlog_limit(int limit)
+static int audit_set_backlog_limit(int limit, uid_t loginuid)
 {
         int old          = audit_backlog_limit;
         audit_backlog_limit = limit;
-        audit_log(current->audit_context, "audit_backlog_limit=%d old=%d",
-                  audit_backlog_limit, old);
+        audit_log(NULL, "audit_backlog_limit=%d old=%d by auid %u",
+                        audit_backlog_limit, old, loginuid);
         return old;
 }
 
-static int audit_set_enabled(int state)
+static int audit_set_enabled(int state, uid_t loginuid)
 {
         int old          = audit_enabled;
         if (state != 0 && state != 1)
                 return -EINVAL;
         audit_enabled = state;
-        audit_log(current->audit_context, "audit_enabled=%d old=%d",
-                  audit_enabled, old);
+        audit_log(NULL, "audit_enabled=%d old=%d by auid %u",
+                  audit_enabled, old, loginuid);
         return old;
 }
 
-static int audit_set_failure(int state)
+static int audit_set_failure(int state, uid_t loginuid)
 {
         int old          = audit_failure;
         if (state != AUDIT_FAIL_SILENT
@@ -276,8 +276,8 @@ static int audit_set_failure(int state)
             && state != AUDIT_FAIL_PANIC)
                 return -EINVAL;
         audit_failure = state;
-        audit_log(current->audit_context, "audit_failure=%d old=%d",
-                  audit_failure, old);
+        audit_log(NULL, "audit_failure=%d old=%d by auid %u",
+                  audit_failure, old, loginuid);
         return old;
 }
 
@@ -344,6 +344,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         int                     err;
         struct audit_buffer     *ab;
         u16                     msg_type = nlh->nlmsg_type;
+        uid_t                   loginuid; /* loginuid of sender */
 
         err = audit_netlink_ok(NETLINK_CB(skb).eff_cap, msg_type);
         if (err)
@@ -351,6 +352,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
 
         pid  = NETLINK_CREDS(skb)->pid;
         uid  = NETLINK_CREDS(skb)->uid;
+        loginuid = NETLINK_CB(skb).loginuid;
         seq  = nlh->nlmsg_seq;
         data = NLMSG_DATA(nlh);
 
@@ -371,34 +373,36 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                         return -EINVAL;
                 status_get   = (struct audit_status *)data;
                 if (status_get->mask & AUDIT_STATUS_ENABLED) {
-                        err = audit_set_enabled(status_get->enabled);
+                        err = audit_set_enabled(status_get->enabled, loginuid);
                         if (err < 0) return err;
                 }
                 if (status_get->mask & AUDIT_STATUS_FAILURE) {
-                        err = audit_set_failure(status_get->failure);
+                        err = audit_set_failure(status_get->failure, loginuid);
                         if (err < 0) return err;
                 }
                 if (status_get->mask & AUDIT_STATUS_PID) {
                         int old   = audit_pid;
                         audit_pid = status_get->pid;
-                        audit_log(current->audit_context,
-                                  "audit_pid=%d old=%d", audit_pid, old);
+                        audit_log(NULL, "audit_pid=%d old=%d by auid %u",
+                                  audit_pid, old, loginuid);
                 }
                 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
-                        audit_set_rate_limit(status_get->rate_limit);
+                        audit_set_rate_limit(status_get->rate_limit, loginuid);
                 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
-                        audit_set_backlog_limit(status_get->backlog_limit);
+                        audit_set_backlog_limit(status_get->backlog_limit,
+                                                        loginuid);
                 break;
         case AUDIT_USER:
                 ab = audit_log_start(NULL);
                 if (!ab)
                         break;  /* audit_panic has been called */
                 audit_log_format(ab,
-                                 "user pid=%d uid=%d length=%d msg='%.1024s'",
+                                 "user pid=%d uid=%d length=%d loginuid=%u"
+                                 " msg='%.1024s'",
                                  pid, uid,
                                  (int)(nlh->nlmsg_len
                                        - ((char *)data - (char *)nlh)),
-                                 (char *)data);
+                                 loginuid, (char *)data);
                 ab->type = AUDIT_USER;
                 ab->pid  = pid;
                 audit_log_end(ab);
@@ -411,7 +415,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         case AUDIT_LIST:
 #ifdef CONFIG_AUDITSYSCALL
                 err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
-                                           uid, seq, data);
+                                           uid, seq, data, loginuid);
 #else
                 err = -EOPNOTSUPP;
 #endif
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 9ff2c1b1033e..66148f81d783 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -251,7 +251,8 @@ static int audit_copy_rule(struct audit_rule *d, struct audit_rule *s)
         return 0;
 }
 
-int audit_receive_filter(int type, int pid, int uid, int seq, void *data)
+int audit_receive_filter(int type, int pid, int uid, int seq, void *data,
+                                                        uid_t loginuid)
 {
         u32                flags;
         struct audit_entry *entry;
@@ -286,6 +287,7 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data)
                         err = audit_add_rule(entry, &audit_entlist);
                 if (!err && (flags & AUDIT_AT_EXIT))
                         err = audit_add_rule(entry, &audit_extlist);
+                audit_log(NULL, "auid %u added an audit rule\n", loginuid);
                 break;
         case AUDIT_DEL:
                 flags =((struct audit_rule *)data)->flags;
@@ -295,6 +297,7 @@ int audit_receive_filter(int type, int pid, int uid, int seq, void *data)
                         err = audit_del_rule(data, &audit_entlist);
                 if (!err && (flags & AUDIT_AT_EXIT))
                         err = audit_del_rule(data, &audit_extlist);
+                audit_log(NULL, "auid %u removed an audit rule\n", loginuid);
                 break;
         default:
                 return -EINVAL;