Bug 65933

Summary: weston-launch -u doesn't work
Product: Wayland Reporter: Ross Burton <ross>
Component: westonAssignee: Wayland bug list <wayland-bugs>
Status: RESOLVED FIXED QA Contact:
Severity: normal    
Priority: medium    
Version: unspecified   
Hardware: Other   
OS: All   
Whiteboard:
i915 platform: i915 features:
Attachments: Patch to set groups for users

Description Ross Burton 2013-06-19 12:45:34 UTC 
When weston-launch is used as root with the -u option to switch to a non-root user, the supplementary group list isn't set so this user is a member of root's group and the primary group of the user (in my situation, the group list is "root xuser").

This doesn't work too well when permissions on /dev/dri/card0 are root:video 660, because this user isn't currently a member of video (despite /etc/group saying otherwise).  Permission denied, weston fails.

It looks like the solution on Linux would be to use getgrouplist()/setgroups() before setgid()/setuid().
Comment 1 Quentin "Sardem FF7" Glidic 2013-06-19 14:18:48 UTC 
Created attachment 81073 [details] [review]
Patch to set groups for users

This patch calls initgroups() if available. Built but not tested.
Comment 2 Ross Burton 2013-06-19 14:48:49 UTC 
Patch works a treat.
Comment 3 Rob Bradford 2013-07-08 10:55:45 UTC 
This patch looks good - could you mail it to the list please?
Comment 4 Kristian Høgsberg 2013-07-08 16:56:59 UTC 
(In reply to comment #3)
> This patch looks good - could you mail it to the list please?

commit 735302ea2d6a281bb326e440c091e95c403f7b7f
Author: Quentin Glidic <sardemff7+git@sardemff7.net>
Date:   Wed Jun 19 15:27:11 2013 +0200

    weston-launch: Set all groups for user
    
    Signed-off-by: Quentin Glidic <sardemff7+git@sardemff7.net>
    
    https://bugs.freedesktop.org/show_bug.cgi?id=65933

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