monitor: monitor_kill_service - refactor

After freeing *svc* return immediately instead of creating event operating on
*svc* (use-after-free). Also check tevent_add_timer failure and remove unused
sigkill_ev variable.

1 files changed, 20 insertions, 8 deletions

diff --git a/src/monitor/monitor.c b/src/monitor/monitor.c
index 5ea4fc930..4c0c22ce9 100644
--- a/src/monitor/monitor.c
+++ b/src/monitor/monitor.c
@@ -126,8 +126,6 @@ struct mt_svc {
     struct tevent_timer *ping_ev;
 
     struct sss_child_ctx *child_ctx;
-
-    struct tevent_timer *sigkill_ev;
 };
 
 struct config_file_callback {
@@ -613,23 +611,37 @@ static int monitor_kill_service (struct mt_svc *svc)
 {
     int ret;
     struct timeval tv;
+    struct tevent_timer *te;
 
     ret = kill(svc->pid, SIGTERM);
-    if (ret != EOK) {
+    if (ret == -1) {
+        ret = errno;
         DEBUG(SSSDBG_FATAL_FAILURE,
-              ("Sending signal to child (%s:%d) failed! "
+              ("Sending signal to child (%s:%d) failed: [%d]: %s! "
                "Ignore and pretend child is dead.\n",
-               svc->name, svc->pid));
-        talloc_free(svc);
+               svc->name, svc->pid, ret, strerror(ret)));
+        goto done;
     }
 
     /* Set up a timer to send SIGKILL if this process
      * doesn't exit within sixty seconds
      */
     tv = tevent_timeval_current_ofs(svc->kill_time, 0);
-    svc->sigkill_ev = tevent_add_timer(svc->mt_ctx->ev, svc, tv,
-                                       mt_svc_sigkill, svc);
+    te = tevent_add_timer(svc->mt_ctx->ev, svc, tv, mt_svc_sigkill, svc);
+    if (te == NULL) {
+        /* Nothing much we can do */
+        ret = ENOMEM;
+        DEBUG(SSSDBG_CRIT_FAILURE,
+              ("Failed to allocate timed event: mt_svc_sigkill.\n"));
+        goto done;
+    }
+
+    ret = EOK;
 
+done:
+    if (ret != EOK) {
+        talloc_free(svc);
+    }
     return ret;
 }