[tor-bugs] #22794 [Applications/Tor Browser]: Don't open AF_INET/AF_INET6 sockets when AF_LOCAL is configured.

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#22794: Don't open AF_INET/AF_INET6 sockets when AF_LOCAL is configured.
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 Reporter:  yawning                              |          Owner:
                                                 |  pospeselr
     Type:  defect                               |         Status:
                                                 |  assigned
 Priority:  Medium                               |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:  Normal                               |     Resolution:
 Keywords:  tbb-security, tbb-sandboxing,        |  Actual Points:
  TorBrowserTeam201801                           |
Parent ID:  #20775                               |         Points:
 Reviewer:                                       |        Sponsor:
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Comment (by yawning):

 Apparently someone really wanted to be able to see this with seccomp, so I
 attached a trivial program that uses libseccomp to initialize a filter
 that will reject `socket(AF_INET[6], ..., ...)` by SIGSYSing the thread.

 Usage:

  1. Compile it.
  2. Set the required env vars to get Tor Browser to talk to a external tor
 process over AF_UNIX sockets.
  3. Run it from the root of a tor browser installation (It calls
 `system("Browser/start-tor-browser");` because it's a trivial test case
 and I'm lazy).
  4. Watch in horror as nothing works.
  5. Run it with strace to see the socket thread traces ending abruptly
 with `+++ killed by SIGSYS +++`.

 The control port appears to work, but any attempt to use the socks port
 get stomped on, so I'm basically convinced that the root cause is the
 non-`AF_INET` socket support in `nsSOCKSIOLayer` being a steaming pile of
 shit.

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Ticket URL: <https://trac.torproject.org/projects/tor/ticket/22794#comment:17>
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