From: Zbigniew Jędrzejewski-Szmek <zbyszek@in.waw.pl>
Date: Wed, 14 Oct 2020 12:03:13 +0000 (+0200)
Subject: sd-bus: break the loop in bus_ensure_running() if the bus is not connecting
X-Git-Tag: v247-rc1~71
X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=93a59b1ae5d3bcb0ec1488ebc13d0d1ff4d1729a;p=thirdparty%2Fsystemd.git

sd-bus: break the loop in bus_ensure_running() if the bus is not connecting

This might fix #17025:
> the call trace is
> bus_ensure_running -> sd_bus_process -> bus_process_internal -> process_closeing --> sd_bus_close
>                                                                                  |
>                                                                                  \-> process_match

We ended doing callouts to the Disconnected matches from bus_ensure_running()
and shouldn't. bus_ensure_running() should never do callouts. This change
should fix this however: once we notice that the connection is going down we
will now fail instantly with ENOTOCONN instead of calling any callbacks.
---

diff --git a/src/libsystemd/sd-bus/sd-bus.c b/src/libsystemd/sd-bus/sd-bus.c
index 015a215c420..f9d426f4f21 100644
--- a/src/libsystemd/sd-bus/sd-bus.c
+++ b/src/libsystemd/sd-bus/sd-bus.c
@@ -2120,12 +2120,13 @@ int bus_ensure_running(sd_bus *bus) {
 
         assert(bus);
 
-        if (IN_SET(bus->state, BUS_UNSET, BUS_CLOSED, BUS_CLOSING))
-                return -ENOTCONN;
         if (bus->state == BUS_RUNNING)
                 return 1;
 
         for (;;) {
+                if (IN_SET(bus->state, BUS_UNSET, BUS_CLOSED, BUS_CLOSING))
+                        return -ENOTCONN;
+
                 r = sd_bus_process(bus, NULL);
                 if (r < 0)
                         return r;