[tor-bugs] #23745 [Applications/Tor Browser]: Tab crashes when using Tor Browser to access Google Drive

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#23745: Tab crashes when using Tor Browser to access Google Drive
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 Reporter:  angelotheram2                        |          Owner:  tbb-
                                                 |  team
     Type:  defect                               |         Status:
                                                 |  assigned
 Priority:  High                                 |      Milestone:
Component:  Applications/Tor Browser             |        Version:
 Severity:  Major                                |     Resolution:
 Keywords:  tbb-crash, tbb-7.0-issues, tbb-      |  Actual Points:
  regression, tbb-e10s, TorBrowserTeam201710     |
Parent ID:                                       |         Points:
 Reviewer:                                       |        Sponsor:
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Comment (by arthuredelstein):

 Replying to [comment:6 gk]:

 > And I think that is good. Getting a clean slate should not depend on
 whether you are in PBM or are allowing disk records for some reason.

 OK, I'm persuaded it's a good idea. Thanks!

 Replying to [comment:5 arthuredelstein]:

 > * indexedDB is a supercookie vector and has not yet been patched to
 respect first-party isolation in Tor Browser or Firefox.
 > * As [https://trac.torproject.org/projects/tor/ticket/16528#comment:7
 mikperry pointed out], there wasn't a good way to programmatically clear
 indexedDB databases. That issue may have been recently fixed in
 [https://bugzilla.mozilla.org/show_bug.cgi?id=1047098 Firefox] and we
 should investigate if we can use this in New Identity.

 I was behind the curve and learned in fact both these problems have
 already been solved:
 * New Identity does appear to wipe indexedDB.
 * indexedDB is first-party isolated in ESR52 (and TBB/ESR52).

 To confirm these two assertions, I did the following experiment:
 1. I set "browser.privatebrowsing.autostart" to false and
 "dom.indexedDB.enabled" to true in Tor Browser 7.0.6.
 2. I opened a New non-PB window and visited
 https://codepen.io/caraya/pen/xVrXrG which allows one to make entries in
 an indexedDB database. I manually entered 3 entries.
 3. I saw in `tor-browser_en-
 US/Browser/TorBrowser/Data/Browser/profile.default/storage/default` that
 there was a directory called
 `https+++s.codepen.io^firstPartyDomain=codepen.io/`.
 4. I restarted Tor Browser, visited the site again and confirmed that my
 database entries were still present.
 5. I clicked "New Identity", visited site once more and saw the the
 database was now reported empty.
 6. I noted that `tor-browser_en-
 US/Browser/TorBrowser/Data/Browser/profile.default/storage/` had been
 deleted, including its subdirectories
 `default/https+++s.codepen.io^firstPartyDomain=codepen.io/`

 FPI of indexedDB was also
 [https://bugzilla.mozilla.org/show_bug.cgi?id=1405884 confirmed to me by a
 few Mozillians]. And I noticed that code in torbutton here:
 https://gitweb.torproject.org/torbutton.git/tree/src/chrome/content/torbutton.js?id=b3ff9863db338b2bd612f109e8bbce4c4af7cbd0#n348
 is likely where the indexedDB wiping is happening. (It might be good to
 update that code to better resemble this Mozilla patch here:
 https://hg.mozilla.org/mozilla-central/rev/0fbe00ad0203#l1.42
 because it doesn't require turning on the "dom.quotaManager.testing" pref;
 I will make a note in #23768.)

 So to me it looks like FPI and clearing on New Identity mean that non-PBM
 indexedDB functionality is already the way we want it in Tor Browser, even
 when dom.indexedDB.enabled = true. And of course PBM windows already
 disabled indexedDB. So I'm inclined to do a little more testing to confirm
 FPI of indexedDB. If nothing bad is found, I would suggest we simply
 revert our #21308 patch, flip the "dom.indexedDB.enabled" pref to true and
 call that a fix for this ticket. gk, what do you think?

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/23745#comment:8>
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