util/main-loop: Fix incorrect assertion

The check for poll_fds in g_assert() was incorrect. The correct assertion should check "n_poll_fds + w->num <= ARRAY_SIZE(poll_fds)" because the subsequent for-loop is doing access to poll_fds[n_poll_fds + i] where i is in [0, w->num). This could happen with a very high number of file descriptors and/or wait objects. Signed-off-by: Lidong Chen <lidong.chen@oracle.com> Suggested-by: Peter Maydell <peter.maydell@linaro.org> Suggested-by: Liam Merwick <liam.merwick@oracle.com> Reviewed-by: Liran Alon <liran.alon@oracle.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Li Qiang <liq3ea@gmail.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Message-Id: <ded30967982811617ce7f0222d11228130c198b7.1560806687.git.lidong.chen@oracle.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
DrenfongWong · Jun 21, 2019 · 6512e34 · 6512e34
1 parent 1c598ab
commit 6512e34
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/util/main-loop.c b/util/main-loop.c
@@ -422,7 +422,7 @@ static int os_host_main_loop_wait(int64_t timeout)
     g_main_context_prepare(context, &max_priority);
     n_poll_fds = g_main_context_query(context, max_priority, &poll_timeout,
                                       poll_fds, ARRAY_SIZE(poll_fds));
-    g_assert(n_poll_fds <= ARRAY_SIZE(poll_fds));
+    g_assert(n_poll_fds + w->num <= ARRAY_SIZE(poll_fds));
 
     for (i = 0; i < w->num; i++) {
         poll_fds[n_poll_fds + i].fd = (DWORD_PTR)w->events[i];