[Qemu-devel] [PATCH] spice-qemu-char: do not use port device when it is not active

[Pavel Grunt <pgrunt@redhat.com>]

Avoid segmentation fault when the webdav channel (spice port channel) is
used with the vnc display:
 #0  0x00007ffff7ab2594 in spice_char_device_state_opaque_get (dev=0x0) at char_device.c:700
 #1  0x00007ffff7b0def3 in spice_server_port_event (sin=<optimized out>, event=<optimized out>) at spicevmc.c:572
 #2  0x0000555555781564 in set_guest_connected (port=<optimized out>, guest_connected=1) at hw/char/virtio-console.c:89
 #3  0x000055555567273c in control_out (len=<optimized out>, buf=0x5555563b3cf0, vser=0x555557906370) at /home/pgrunt/RH/qemu/hw/char/virtio-serial-bus.c:404
 #4  0x000055555567273c in control_out (vdev=0x555557906370, vq=0x5555579769f0) at /home/pgrunt/RH/qemu/hw/char/virtio-serial-bus.c:441
 #5  0x0000555555883678 in aio_dispatch (ctx=0x5555562d9db0) at aio-posix.c:156
 #6  0x0000555555876f5e in aio_ctx_dispatch (source=<optimized out>, callback=<optimized out>, user_data=<optimized out>) at async.c:226
 #7  0x00007ffff618ff0a in g_main_context_dispatch (context=0x5555562dae00) at gmain.c:3154
 #8  0x00007ffff618ff0a in g_main_context_dispatch (context=context@entry=0x5555562dae00) at gmain.c:3769
 #9  0x00005555558823fb in main_loop_wait () at main-loop.c:211
 #10 0x00005555558823fb in main_loop_wait (timeout=<optimized out>) at main-loop.c:256
 #11 0x00005555558823fb in main_loop_wait (nonblocking=<optimized out>) at main-loop.c:504
 #12 0x000055555561514c in main () at vl.c:1879
 #13 0x000055555561514c in main (argc=<optimized out>, argv=<optimized out>, envp=<optimized out>) at vl.c:4633

Signed-off-by: Pavel Grunt <pgrunt@redhat.com>
---
I just changed the display of a VM from Spice to VNC in virt-manager, started the VM and the crash occurred.
The VM is the latest Fedora with spice-webdavd installed.
---
 spice-qemu-char.c | 12 ++++++++++++
 1 file changed, 12 insertions(+)

diff --git a/spice-qemu-char.c b/spice-qemu-char.c
index d41bb74..840c181 100644
--- a/spice-qemu-char.c
+++ b/spice-qemu-char.c
@@ -229,6 +229,12 @@ static void spice_port_set_fe_open(struct CharDriverState *chr, int fe_open)
 #if SPICE_SERVER_VERSION >= 0x000c02
     SpiceCharDriver *s = chr->opaque;
 
+    if (!s->active) {
+        fprintf(stderr, "spice-qemu-char: port '%s' is not active\n",
+                s->sin.portname);
+        return;
+    }
+
     if (fe_open) {
         spice_server_port_event(&s->sin, SPICE_PORT_EVENT_OPENED);
     } else {
@@ -242,6 +248,12 @@ static void spice_chr_fe_event(struct CharDriverState *chr, int event)
 #if SPICE_SERVER_VERSION >= 0x000c02
     SpiceCharDriver *s = chr->opaque;
 
+    if (!s->active) {
+        fprintf(stderr, "spice-qemu-char: port '%s' is not active\n",
+                s->sin.portname);
+        return;
+    }
+
     spice_server_port_event(&s->sin, event);
 #endif
 }
-- 
2.5.0