62814 - When running as untrusted X11 client, attempting to copy text to clipboard crashes

Status: NEW

(Core :: XUL, defect, P3)

Description

[Roland Mainz]

Mozilla (2000-12-06-08-Mtrunk) cannot run as "untrusted" X11 client - any
attempt to access restricted/disabled resources (like X atoms) will end in a
uncatched X protocol error (exit).

Example:
% xauth -f myauth generate :0.0 MIT-MAGIC-COOKIE-1 untrusted
% export XAUTHORITY=$PWD/myauth
% ./mozilla
[blah-blah]
# user selects something in Mozilla and likes to "Paste" that into another
application. Result:
Enabling Quirk StyleSheet
Opening file cookperm.txt failed
in SetSecurityButton
Enabling Quirk StyleSheet
WARNING: not calling OnDataAvailable, file
../../../../netwerk/base/src/nsAsyncStreamListener.cpp, line 410
Document http://www.mozilla.org/ loaded successfully
WEBSHELL+ = 4
WARNING: not calling OnDataAvailable, file
../../../../netwerk/base/src/nsAsyncStreamListener.cpp, line 410
clearing PRIMARY clipboard
clearing CLIPBOARD clipboard
nsWidget::~nsWidget() of toplevel: 15 widgets still exist.
X Error of failed request:  BadAtom (invalid Atom parameter)
  Major opcode of failed request:  18 (X_ChangeProperty)
  Atom id in failed request:  0xa9
  Serial number of failed request:  4442
  Current serial number in output stream:  4444
X Error of failed request:  BadAccess (attempt to access private resource
denied)
  Major opcode of failed request:  102 (X_ChangeKeyboardControl)
  Serial number of failed request:  4445
  Current serial number in output stream:  4450
%

(no coredump)
This happens on both Linux and Solaris...

Does anyone here needs an explanation what an untrusted X client is ?

Comment 1

[Peter Trudelle]

->pavlov for triage, cc bryner in case he can field it.

Comment 2

[Stuart Parmenter]

i'm sorry. I don't know what exactly you expect.  Sure, we could try and catch 
all the X errors, but that seems pretty stupid.  Would you rather the app start 
and just exit saying "make me trusted" ?

Comment 3

[Roland Mainz]

> Would you rather the app start and just exit saying "make me trusted" ?

Mhhh, what happens if someone embeds Mozilla in a WWW page (e.g. Xweb plugin,
see libxrx(1)) ?
In this case the people do not like to allow any "alien" X app. to access all X
atoms - this is why the X11 SECURITY extension was designed for (anyone remember
that nice "xkey" application which records all keystrokes of a remote $DISPLAY
??)...

Assuming this would be a "real" error you would be right - we could ignore the
problem.

But this isn't an error - this is simply a problem that the application isn't
allowed to read or write a X atom due restrictions set by Xserver's SECURITY
extension policy.

Does /usr/bin/cat crash when it attempts to open a file which cannot be read
with it's fs creds ?

Comment 4

[Wayne Mery (:wsmwk)]

is this still an issue?

Comment 5

[rsx11m]

(In reply to Roland Mainz from comment #0)
> Example:
> % xauth -f myauth generate :0.0 MIT-MAGIC-COOKIE-1 untrusted
> % export XAUTHORITY=$PWD/myauth
> % ./mozilla

Trying this with a reasonably current SM 2.35a1 build and DISPLAY=:0.0, I have no problems starting up with the default ~/.Xauthority, but it won't start up with the "myauth" configuration as described (terminates immediately, just producing "Invalid MIT-MAGIC-COOKIE-1 key" twice and then saying "Error: cannot open display: :0.0" before exiting). You'll have to cp ~/.Xauthority myauth first before calling the xauth command as given.

Having done that, I can't force a crash with either just highlighting and pasting into LibreOffice or Ctrl+C/Ctrl+V. Either action briefly stalls the xorg server without anything else happening. There are no messages in the Error Console, nothing in the system logs, and Klipper doesn't indicate that anything has been put onto the clipboard.

Thus, for the purpose of crashing with this xauth configuration, that's a WFM in this case.