[tor-bugs] #23590 [Applications/Tor Browser]: Tor Browser needs write access to /dev/shm

[Tor Bug Tracker & Wiki]

#23590: Tor Browser needs write access to /dev/shm
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     Reporter:  cypherpunks               |      Owner:  tbb-team
         Type:  defect                    |     Status:  new
     Priority:  Medium                    |  Milestone:
    Component:  Applications/Tor Browser  |    Version:
     Severity:  Normal                    |   Keywords:
Actual Points:                            |  Parent ID:
       Points:                            |   Reviewer:
      Sponsor:                            |
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 A user on the Tor IRC was having problems running Tor Browser, with the
 browser not starting up and outputting an error:

 `Crash Annotation GraphicsCriticalError: |[0][GFX1-]: Failed 2 buffer`

 Searching the error gave few results, but eventually I stumbled across a
 blog post suggesting that the problem was related to the filesystem
 permissions of `/dev/shm`: https://gkiseki.wordpress.com/2017/07/25
 /slackware-currentの不具合/

 On my system (Gentoo GNU/Linux), Tor Browser works, and `/dev/shm` is mode
 1777 (readable/writable by all, with sticky bit set). On his system
 (Debian GNU/Linux), it is mode 755 instead (readable/writable by root,
 readable by world). When he switched to mode 1777, the browser finally
 opened, and the error went away.

 Many systems have this directory set to mode 755 or even 700 permissions,
 which would suggest that these systems will not be able to run Tor
 Browser. I didn't look into this in detail, but it appears to be related
 to Glib's graphics handling.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/23590>
Tor Bug Tracker & Wiki <https://trac.torproject.org/>
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