[AUDIT] add session id to audit messages

In order to correlate audit records to an individual login add a session
id.  This is incremented every time a user logs in and is included in
almost all messages which currently output the auid.  The field is
labeled ses=  or oses=

Signed-off-by: Eric Paris <eparis@redhat.com>

1 files changed, 27 insertions, 9 deletions

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index a222e73fec74..4e67abb02904 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -178,6 +178,7 @@ struct audit_aux_data_pids {
         pid_t                   target_pid[AUDIT_AUX_PIDS];
         uid_t                   target_auid[AUDIT_AUX_PIDS];
         uid_t                   target_uid[AUDIT_AUX_PIDS];
+        unsigned int            target_sessionid[AUDIT_AUX_PIDS];
         u32                     target_sid[AUDIT_AUX_PIDS];
         char                    target_comm[AUDIT_AUX_PIDS][TASK_COMM_LEN];
         int                     pid_count;
@@ -219,6 +220,7 @@ struct audit_context {
         pid_t               target_pid;
         uid_t               target_auid;
         uid_t               target_uid;
+        unsigned int        target_sessionid;
         u32                 target_sid;
         char                target_comm[TASK_COMM_LEN];
 
@@ -936,7 +938,8 @@ static void audit_log_task_info(struct audit_buffer *ab, struct task_struct *tsk
 }
 
 static int audit_log_pid_context(struct audit_context *context, pid_t pid,
-                                 uid_t auid, uid_t uid, u32 sid, char *comm)
+                                 uid_t auid, uid_t uid, unsigned int sessionid,
+                                 u32 sid, char *comm)
 {
         struct audit_buffer *ab;
         char *s = NULL;
@@ -947,7 +950,8 @@ static int audit_log_pid_context(struct audit_context *context, pid_t pid,
         if (!ab)
                 return 1;
 
-        audit_log_format(ab, "opid=%d oauid=%d ouid=%d", pid, auid, uid);
+        audit_log_format(ab, "opid=%d oauid=%d ouid=%d oses=%d", pid, auid,
+                         uid, sessionid);
         if (selinux_sid_to_string(sid, &s, &len)) {
                 audit_log_format(ab, " obj=(none)");
                 rc = 1;
@@ -1056,7 +1060,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                   " a0=%lx a1=%lx a2=%lx a3=%lx items=%d"
                   " ppid=%d pid=%d auid=%u uid=%u gid=%u"
                   " euid=%u suid=%u fsuid=%u"
-                  " egid=%u sgid=%u fsgid=%u tty=%s",
+                  " egid=%u sgid=%u fsgid=%u tty=%s ses=%u",
                   context->argv[0],
                   context->argv[1],
                   context->argv[2],
@@ -1068,7 +1072,8 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                   context->uid,
                   context->gid,
                   context->euid, context->suid, context->fsuid,
-                  context->egid, context->sgid, context->fsgid, tty);
+                  context->egid, context->sgid, context->fsgid, tty,
+                  tsk->sessionid);
 
         mutex_unlock(&tty_mutex);
 
@@ -1187,6 +1192,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
                         if (audit_log_pid_context(context, axs->target_pid[i],
                                                   axs->target_auid[i],
                                                   axs->target_uid[i],
+                                                  axs->target_sessionid[i],
                                                   axs->target_sid[i],
                                                   axs->target_comm[i]))
                                 call_panic = 1;
@@ -1195,6 +1201,7 @@ static void audit_log_exit(struct audit_context *context, struct task_struct *ts
         if (context->target_pid &&
             audit_log_pid_context(context, context->target_pid,
                                   context->target_auid, context->target_uid,
+                                  context->target_sessionid,
                                   context->target_sid, context->target_comm))
                         call_panic = 1;
 
@@ -1787,6 +1794,9 @@ void auditsc_get_stamp(struct audit_context *ctx,
         ctx->auditable = 1;
 }
 
+/* global counter which is incremented every time something logs in */
+static atomic_t session_id = ATOMIC_INIT(0);
+
 /**
  * audit_set_loginuid - set a task's audit_context loginuid
  * @task: task whose audit context is being modified
@@ -1798,6 +1808,7 @@ void auditsc_get_stamp(struct audit_context *ctx,
  */
 int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
 {
+        unsigned int sessionid = atomic_inc_return(&session_id);
         struct audit_context *context = task->audit_context;
 
         if (context && context->in_syscall) {
@@ -1806,12 +1817,15 @@ int audit_set_loginuid(struct task_struct *task, uid_t loginuid)
                 ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_LOGIN);
                 if (ab) {
                         audit_log_format(ab, "login pid=%d uid=%u "
-                                "old auid=%u new auid=%u",
+                                "old auid=%u new auid=%u"
+                                " old ses=%u new ses=%u",
                                 task->pid, task->uid,
-                                task->loginuid, loginuid);
+                                task->loginuid, loginuid,
+                                task->sessionid, sessionid);
                         audit_log_end(ab);
                 }
         }
+        task->sessionid = sessionid;
         task->loginuid = loginuid;
         return 0;
 }
@@ -2200,6 +2214,7 @@ void __audit_ptrace(struct task_struct *t)
         context->target_pid = t->pid;
         context->target_auid = audit_get_loginuid(t);
         context->target_uid = t->uid;
+        context->target_sessionid = audit_get_sessionid(t);
         selinux_get_task_sid(t, &context->target_sid);
         memcpy(context->target_comm, t->comm, TASK_COMM_LEN);
 }
@@ -2240,6 +2255,7 @@ int __audit_signal_info(int sig, struct task_struct *t)
                 ctx->target_pid = t->tgid;
                 ctx->target_auid = audit_get_loginuid(t);
                 ctx->target_uid = t->uid;
+                ctx->target_sessionid = audit_get_sessionid(t);
                 selinux_get_task_sid(t, &ctx->target_sid);
                 memcpy(ctx->target_comm, t->comm, TASK_COMM_LEN);
                 return 0;
@@ -2260,6 +2276,7 @@ int __audit_signal_info(int sig, struct task_struct *t)
         axp->target_pid[axp->pid_count] = t->tgid;
         axp->target_auid[axp->pid_count] = audit_get_loginuid(t);
         axp->target_uid[axp->pid_count] = t->uid;
+        axp->target_sessionid[axp->pid_count] = audit_get_sessionid(t);
         selinux_get_task_sid(t, &axp->target_sid[axp->pid_count]);
         memcpy(axp->target_comm[axp->pid_count], t->comm, TASK_COMM_LEN);
         axp->pid_count++;
@@ -2278,6 +2295,8 @@ void audit_core_dumps(long signr)
 {
         struct audit_buffer *ab;
         u32 sid;
+        uid_t auid = audit_get_loginuid(current);
+        unsigned int sessionid = audit_get_sessionid(current);
 
         if (!audit_enabled)
                 return;
@@ -2286,9 +2305,8 @@ void audit_core_dumps(long signr)
                 return;
 
         ab = audit_log_start(NULL, GFP_KERNEL, AUDIT_ANOM_ABEND);
-        audit_log_format(ab, "auid=%u uid=%u gid=%u",
-                        audit_get_loginuid(current),
-                        current->uid, current->gid);
+        audit_log_format(ab, "auid=%u uid=%u gid=%u ses=%u",
+                        auid, current->uid, current->gid, sessionid);
         selinux_get_task_sid(current, &sid);
         if (sid) {
                 char *ctx = NULL;