Bug#629248: cheese: segmentation fault when permission is denied to video device

[Márton Németh]

Package: cheese
Version: 2.30.1-2
Severity: normal


When the user has access rights to /dev/video0 then cheese runs correctly:

$ ls -la /dev/video0 
crw-rw----+ 1 root video 81, 0 Jun  5 00:14 /dev/video0
$ groups 
nmarci dialout cdrom floppy audio dip video plugdev
$ cheese 

Whent the user has not the necessary rights then cheese crashes with segmentation fault right after startup:

$ sudo chmod 600 /dev/video0 
$ ls -la /dev/video0 
crw-------+ 1 root video 81, 0 Jun  5 00:14 /dev/video0
$ cheese 
Segmentation fault

My first investigations leaded to cheese_camera_create_camera_source_bin() function in libcheese/cheese-camera.c , where the library function gst_parse_bin_from_description() is called. I guess this library function shall return NULL if an error occured, according to http://gstreamer.freedesktop.org/data/doc/gstreamer/head/gstreamer/html/gstreamer-GstParse.html#gst-parse-bin-from-description . As far as my investigations gone so far the function gst_parse_bin_from_description() does not return NULL when the /dev/video0 is not accessible. Later on this causes segmentation fault in cheese.


-- System Information:
Debian Release: 6.0.1
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: i386 (i686)

Kernel: Linux 3.0.0-rc1 (SMP w/2 CPU cores; PREEMPT)
Locale: LANG=hu_HU.UTF-8, LC_CTYPE=hu_HU.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages cheese depends on:
ii  cheese-common          2.30.1-2          Common files for the Cheese tool t
ii  gstreamer0.10-plugins- 0.10.30-1         GStreamer plugins from the "base" 
ii  gstreamer0.10-plugins- 0.10.24-1         GStreamer plugins from the "good" 
ii  gstreamer0.10-x        0.10.30-1         GStreamer plugins for X11 and Pang
ii  libc6                  2.11.2-10         Embedded GNU C Library: Shared lib
ii  libcairo2              1.8.10-6          The Cairo 2D vector graphics libra
ii  libcanberra-gtk0       0.24-1            Gtk+ helper for playing widget eve
ii  libcheese-gtk18        2.30.1-2          A tool to take pictures and videos
ii  libdbus-glib-1-2       0.88-2.1          simple interprocess messaging syst
ii  libgconf2-4            2.28.1-6          GNOME configuration database syste
ii  libglib2.0-0           2.24.2-1          The GLib library of C routines
ii  libgnome-desktop-2-17  2.30.2-2          Utility library for loading .deskt
ii  libgstreamer-plugins-b 0.10.30-1         GStreamer libraries from the "base
ii  libgstreamer0.10-0     0.10.30-1         Core GStreamer libraries and eleme
ii  libgtk2.0-0            2.20.1-2          The GTK+ graphical user interface 
ii  libgudev-1.0-0         164-3             GObject-based wrapper library for 
ii  libpango1.0-0          1.28.3-1+squeeze2 Layout and rendering of internatio
ii  librsvg2-2             2.26.3-1          SAX-based renderer library for SVG

Versions of packages cheese recommends:
ii  gnome-icon-theme              2.30.3-2   GNOME Desktop icon theme
ii  gvfs                          1.6.4-3    userspace virtual filesystem - ser

cheese suggests no packages.

-- no debconf information