Audit: collect sessionid in netlink messages

Previously I added sessionid output to all audit messages where it was
available but we still didn't know the sessionid of the sender of
netlink messages.  This patch adds that information to netlink messages
so we can audit who sent netlink messages.

Signed-off-by: Eric Paris <eparis@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

1 files changed, 40 insertions, 32 deletions

diff --git a/kernel/audit.c b/kernel/audit.c
index a7b16086d36f..ad6d1abfa1d2 100644
--- a/kernel/audit.c
+++ b/kernel/audit.c
@@ -252,14 +252,15 @@ void audit_log_lost(const char *message)
 }
 
 static int audit_log_config_change(char *function_name, int new, int old,
-                                   uid_t loginuid, u32 sid, int allow_changes)
+                                   uid_t loginuid, u32 sessionid, u32 sid,
+                                   int allow_changes)
 {
         struct audit_buffer *ab;
         int rc = 0;
 
         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_CONFIG_CHANGE);
-        audit_log_format(ab, "%s=%d old=%d by auid=%u", function_name, new,
-                         old, loginuid);
+        audit_log_format(ab, "%s=%d old=%d auid=%u ses=%u", function_name, new,
+                         old, loginuid, sessionid);
         if (sid) {
                 char *ctx = NULL;
                 u32 len;
@@ -279,7 +280,8 @@ static int audit_log_config_change(char *function_name, int new, int old,
 }
 
 static int audit_do_config_change(char *function_name, int *to_change,
-                                  int new, uid_t loginuid, u32 sid)
+                                  int new, uid_t loginuid, u32 sessionid,
+                                  u32 sid)
 {
         int allow_changes, rc = 0, old = *to_change;
 
@@ -290,8 +292,8 @@ static int audit_do_config_change(char *function_name, int *to_change,
                 allow_changes = 1;
 
         if (audit_enabled != AUDIT_OFF) {
-                rc = audit_log_config_change(function_name, new, old,
-                                             loginuid, sid, allow_changes);
+                rc = audit_log_config_change(function_name, new, old, loginuid,
+                                             sessionid, sid, allow_changes);
                 if (rc)
                         allow_changes = 0;
         }
@@ -305,26 +307,28 @@ static int audit_do_config_change(char *function_name, int *to_change,
         return rc;
 }
 
-static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sid)
+static int audit_set_rate_limit(int limit, uid_t loginuid, u32 sessionid,
+                                u32 sid)
 {
         return audit_do_config_change("audit_rate_limit", &audit_rate_limit,
-                                      limit, loginuid, sid);
+                                      limit, loginuid, sessionid, sid);
 }
 
-static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sid)
+static int audit_set_backlog_limit(int limit, uid_t loginuid, u32 sessionid,
+                                   u32 sid)
 {
         return audit_do_config_change("audit_backlog_limit", &audit_backlog_limit,
-                                      limit, loginuid, sid);
+                                      limit, loginuid, sessionid, sid);
 }
 
-static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
+static int audit_set_enabled(int state, uid_t loginuid, u32 sessionid, u32 sid)
 {
         int rc;
         if (state < AUDIT_OFF || state > AUDIT_LOCKED)
                 return -EINVAL;
 
         rc =  audit_do_config_change("audit_enabled", &audit_enabled, state,
-                                     loginuid, sid);
+                                     loginuid, sessionid, sid);
 
         if (!rc)
                 audit_ever_enabled |= !!state;
@@ -332,7 +336,7 @@ static int audit_set_enabled(int state, uid_t loginuid, u32 sid)
         return rc;
 }
 
-static int audit_set_failure(int state, uid_t loginuid, u32 sid)
+static int audit_set_failure(int state, uid_t loginuid, u32 sessionid, u32 sid)
 {
         if (state != AUDIT_FAIL_SILENT
             && state != AUDIT_FAIL_PRINTK
@@ -340,7 +344,7 @@ static int audit_set_failure(int state, uid_t loginuid, u32 sid)
                 return -EINVAL;
 
         return audit_do_config_change("audit_failure", &audit_failure, state,
-                                      loginuid, sid);
+                                      loginuid, sessionid, sid);
 }
 
 static int kauditd_thread(void *dummy)
@@ -385,7 +389,7 @@ static int kauditd_thread(void *dummy)
         return 0;
 }
 
-static int audit_prepare_user_tty(pid_t pid, uid_t loginuid)
+static int audit_prepare_user_tty(pid_t pid, uid_t loginuid, u32 sessionid)
 {
         struct task_struct *tsk;
         int err;
@@ -404,7 +408,7 @@ static int audit_prepare_user_tty(pid_t pid, uid_t loginuid)
         if (err)
                 goto out;
 
-        tty_audit_push_task(tsk, loginuid);
+        tty_audit_push_task(tsk, loginuid, sessionid);
 out:
         read_unlock(&tasklist_lock);
         return err;
@@ -534,7 +538,8 @@ static int audit_netlink_ok(struct sk_buff *skb, u16 msg_type)
 }
 
 static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
-                                     u32 pid, u32 uid, uid_t auid, u32 sid)
+                                     u32 pid, u32 uid, uid_t auid, u32 ses,
+                                     u32 sid)
 {
         int rc = 0;
         char *ctx = NULL;
@@ -546,8 +551,8 @@ static int audit_log_common_recv_msg(struct audit_buffer **ab, u16 msg_type,
         }
 
         *ab = audit_log_start(NULL, GFP_KERNEL, msg_type);
-        audit_log_format(*ab, "user pid=%d uid=%u auid=%u",
-                         pid, uid, auid);
+        audit_log_format(*ab, "user pid=%d uid=%u auid=%u ses=%u",
+                         pid, uid, auid, ses);
         if (sid) {
                 rc = security_secid_to_secctx(sid, &ctx, &len);
                 if (rc)
@@ -570,6 +575,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         struct audit_buffer     *ab;
         u16                     msg_type = nlh->nlmsg_type;
         uid_t                   loginuid; /* loginuid of sender */
+        u32                     sessionid;
         struct audit_sig_info   *sig_data;
         char                    *ctx = NULL;
         u32                     len;
@@ -591,6 +597,7 @@ 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;
+        sessionid = NETLINK_CB(skb).sessionid;
         sid  = NETLINK_CB(skb).sid;
         seq  = nlh->nlmsg_seq;
         data = NLMSG_DATA(nlh);
@@ -613,12 +620,12 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 status_get   = (struct audit_status *)data;
                 if (status_get->mask & AUDIT_STATUS_ENABLED) {
                         err = audit_set_enabled(status_get->enabled,
-                                                        loginuid, sid);
+                                                loginuid, sessionid, sid);
                         if (err < 0) return err;
                 }
                 if (status_get->mask & AUDIT_STATUS_FAILURE) {
                         err = audit_set_failure(status_get->failure,
-                                                         loginuid, sid);
+                                                loginuid, sessionid, sid);
                         if (err < 0) return err;
                 }
                 if (status_get->mask & AUDIT_STATUS_PID) {
@@ -627,17 +634,17 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                         if (audit_enabled != AUDIT_OFF)
                                 audit_log_config_change("audit_pid", new_pid,
                                                         audit_pid, loginuid,
-                                                        sid, 1);
+                                                        sessionid, sid, 1);
 
                         audit_pid = new_pid;
                         audit_nlk_pid = NETLINK_CB(skb).pid;
                 }
                 if (status_get->mask & AUDIT_STATUS_RATE_LIMIT)
                         err = audit_set_rate_limit(status_get->rate_limit,
-                                                         loginuid, sid);
+                                                   loginuid, sessionid, sid);
                 if (status_get->mask & AUDIT_STATUS_BACKLOG_LIMIT)
                         err = audit_set_backlog_limit(status_get->backlog_limit,
-                                                        loginuid, sid);
+                                                      loginuid, sessionid, sid);
                 break;
         case AUDIT_USER:
         case AUDIT_FIRST_USER_MSG ... AUDIT_LAST_USER_MSG:
@@ -649,12 +656,13 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 if (err == 1) {
                         err = 0;
                         if (msg_type == AUDIT_USER_TTY) {
-                                err = audit_prepare_user_tty(pid, loginuid);
+                                err = audit_prepare_user_tty(pid, loginuid,
+                                                             sessionid);
                                 if (err)
                                         break;
                         }
                         audit_log_common_recv_msg(&ab, msg_type, pid, uid,
-                                                  loginuid, sid);
+                                                  loginuid, sessionid, sid);
 
                         if (msg_type != AUDIT_USER_TTY)
                                 audit_log_format(ab, " msg='%.1024s'",
@@ -677,7 +685,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                         return -EINVAL;
                 if (audit_enabled == AUDIT_LOCKED) {
                         audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
-                                                  uid, loginuid, sid);
+                                                  uid, loginuid, sessionid, sid);
 
                         audit_log_format(ab, " audit_enabled=%d res=0",
                                          audit_enabled);
@@ -688,7 +696,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         case AUDIT_LIST:
                 err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
                                            uid, seq, data, nlmsg_len(nlh),
-                                           loginuid, sid);
+                                           loginuid, sessionid, sid);
                 break;
         case AUDIT_ADD_RULE:
         case AUDIT_DEL_RULE:
@@ -696,7 +704,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                         return -EINVAL;
                 if (audit_enabled == AUDIT_LOCKED) {
                         audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
-                                                  uid, loginuid, sid);
+                                                  uid, loginuid, sessionid, sid);
 
                         audit_log_format(ab, " audit_enabled=%d res=0",
                                          audit_enabled);
@@ -707,13 +715,13 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
         case AUDIT_LIST_RULES:
                 err = audit_receive_filter(nlh->nlmsg_type, NETLINK_CB(skb).pid,
                                            uid, seq, data, nlmsg_len(nlh),
-                                           loginuid, sid);
+                                           loginuid, sessionid, sid);
                 break;
         case AUDIT_TRIM:
                 audit_trim_trees();
 
                 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
-                                          uid, loginuid, sid);
+                                          uid, loginuid, sessionid, sid);
 
                 audit_log_format(ab, " op=trim res=1");
                 audit_log_end(ab);
@@ -745,7 +753,7 @@ static int audit_receive_msg(struct sk_buff *skb, struct nlmsghdr *nlh)
                 err = audit_tag_tree(old, new);
 
                 audit_log_common_recv_msg(&ab, AUDIT_CONFIG_CHANGE, pid,
-                                          uid, loginuid, sid);
+                                          uid, loginuid, sessionid, sid);
 
                 audit_log_format(ab, " op=make_equiv old=");
                 audit_log_untrustedstring(ab, old);