Set up signal handlers before initializing sysdb

A temporary signal handler for SIGTERM is set up in server_setup()
that calls exit() from within a pure signal handler. This causes a
race condition where it's possible that if the SSSD is restarted
immediately while it is still initializing the sysdb caches for
the first time, it can leave the cache in a corrupt and unusable
state.

https://bugzilla.redhat.com/show_bug.cgi?id=658444

1 files changed, 30 insertions, 29 deletions

diff --git a/src/monitor/monitor.c b/src/monitor/monitor.c
index ac55d7c3..1a62f69a 100644
--- a/src/monitor/monitor.c
+++ b/src/monitor/monitor.c
@@ -1769,6 +1769,36 @@ int monitor_process_init(struct mt_ctx *ctx,
     int num_providers;
     int ret;
 
+    /* Set up an event handler for a SIGHUP */
+    tes = tevent_add_signal(ctx->ev, ctx, SIGHUP, 0,
+                            monitor_hup, ctx);
+    if (tes == NULL) {
+        return EIO;
+    }
+
+    /* Set up an event handler for a SIGINT */
+    BlockSignals(false, SIGINT);
+    tes = tevent_add_signal(ctx->ev, ctx, SIGINT, 0,
+                            monitor_quit, ctx);
+    if (tes == NULL) {
+        return EIO;
+    }
+
+    /* Set up an event handler for a SIGTERM */
+    tes = tevent_add_signal(ctx->ev, ctx, SIGTERM, 0,
+                            monitor_quit, ctx);
+    if (tes == NULL) {
+        return EIO;
+    }
+
+    /* Handle SIGUSR1 (tell all providers to go offline) */
+    BlockSignals(false, SIGUSR1);
+    tes = tevent_add_signal(ctx->ev, ctx, SIGUSR1, 0,
+                            signal_offline, ctx);
+    if (tes == NULL) {
+        return EIO;
+    }
+
 #if 0
     This feature is incomplete and can leave the SSSD in a bad state if the
     config file is changed while the SSSD is running.
@@ -1846,35 +1876,6 @@ int monitor_process_init(struct mt_ctx *ctx,
     /* now start checking for global events */
     set_global_checker(ctx);
 
-    /* Set up an event handler for a SIGHUP */
-    tes = tevent_add_signal(ctx->ev, ctx, SIGHUP, 0,
-                            monitor_hup, ctx);
-    if (tes == NULL) {
-        return EIO;
-    }
-
-    /* Set up an event handler for a SIGINT */
-    tes = tevent_add_signal(ctx->ev, ctx, SIGINT, 0,
-                            monitor_quit, ctx);
-    if (tes == NULL) {
-        return EIO;
-    }
-
-    /* Set up an event handler for a SIGTERM */
-    tes = tevent_add_signal(ctx->ev, ctx, SIGTERM, 0,
-                            monitor_quit, ctx);
-    if (tes == NULL) {
-        return EIO;
-    }
-
-    /* Handle SIGUSR1 (tell all providers to go offline) */
-    BlockSignals(false, SIGUSR1);
-    tes = tevent_add_signal(ctx->ev, ctx, SIGUSR1, 0,
-                            signal_offline, ctx);
-    if (tes == NULL) {
-        return EIO;
-    }
-
     return EOK;
 }