[Pkg-xfce-devel] Bug#712868: xfce4-settings-helper generates segfault when running under VNC

Koehrer Mathias (ETAS/ESS2) mathias.koehrer at etas.com
Thu Jun 20 11:17:26 UTC 2013

Package: xfce4-settings
Version: 4.8.3-2
Severity: important
Tags: patch

Dear Maintainer,

when running xfce4 under VNC (vnc4server), xfce4-settings-helper
generates a segfault.
kernel: xfce4-settings-[20447]: segfault at 1 ip 8000936e sp bffff270
error 4 in xfce4-settings-helper[80000000+f000]

I debugged and identifed the issue:
When running under VNC, the function XGetExtensionVersion returns "1".
This is not considered in xfce_pointers_helper_init().

The following patch fixes the issue.

Thanks for processing this issue.




Author: Mathias Koehrer <mathias.koehrer at etas.com>

--- xfce4-settings-4.8.3.orig/xfce4-settings-helper/pointers.c
+++ xfce4-settings-4.8.3/xfce4-settings-helper/pointers.c
@@ -135,8 +135,11 @@ xfce_pointers_helper_init (XfcePointersH
     /* query the extension version */
     version = XGetExtensionVersion (xdisplay, INAME);
-    /* check for Xi */
-    if (version == NULL || !version->present)
+    /* check for Xi.
+     * Note: if running under VNC, XGetExtensionVersion returns a pointer
+     * with the address "1". This has to be considered here.
+     * */
+    if (version == NULL || version == (void*)1 || !version->present)
         g_critical ("XI is not present.");

-- System Information:
Debian Release: 7.1
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 3.2.46-rt67-2 (SMP w/8 CPU cores; PREEMPT)
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /bin/dash

Versions of packages xfce4-settings depends on:
ii  libc6               2.13-38
ii  libcairo2           1.12.2-3
ii  libdbus-1-3         1.6.8-1
ii  libexo-1-0          0.6.2-5
ii  libgdk-pixbuf2.0-0  2.26.1-1
ii  libglib2.0-0        2.33.12+really2.32.4-5
ii  libgtk2.0-0         2.24.10-2
ii  libnotify4          0.7.5-1
ii  libpango1.0-0       1.30.0-1
ii  libx11-6            2:1.5.0-1+deb7u1
ii  libxcursor1         1:1.1.13-1+deb7u1
ii  libxfce4ui-1-0      4.8.1-1
ii  libxfce4util4       4.8.2-1
ii  libxfconf-0-2       4.8.1-1
ii  libxi6              2:1.6.1-1+deb7u1
ii  libxklavier16       5.2.1-1
ii  libxrandr2          2:1.3.2-2+deb7u1
ii  xfconf              4.8.1-1

Versions of packages xfce4-settings recommends:
ii  x11-utils      7.7~1
pn  xfce4-volumed  <none>

xfce4-settings suggests no packages.

-- no debconf information

More information about the Pkg-xfce-devel mailing list