alsa: fix bad memory access for devices that lack a mixer

diff --git a/src/modules/alsa/alsa-util.c b/src/modules/alsa/alsa-util.c
index c03866cc30672c31ff76479b762bdce483866e27..b27362524282325378133f0831947d9d1e1b33ed 100644 (file)
--- a/src/modules/alsa/alsa-util.c
+++ b/src/modules/alsa/alsa-util.c
@@ -1289,8 +1289,10 @@ int pa_alsa_find_mixer_and_elem(
     }
 
     if (!e) {
-        if (ctl_device)
+        if (ctl_device) {
             pa_xfree(*ctl_device);
+            *ctl_device = NULL;
+        }
 
         snd_mixer_close(m);
         return -1;