1286621 - Private browsing mode leaks info to about:networking

Status: VERIFIED FIXED

(Core :: Networking, defect)

Description

[[e-mail]]

User Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.11; rv:47.0) Gecko/20100101 Firefox/47.0
Build ID: 20160623154057

Steps to reproduce:

Open a private browsing tab
Type in www.kmart.com in the url bar
Go back to the regular (non private) window
Type about:networking in the search bar




Actual results:

You will find kmart under the DNS section


Expected results:

I would've expected nothing from my private browsing window to show up in about:networking.

Comment 1

[Patrick McManus [:mcmanus]]

confirm you closed the private browsing window.. ?

Comment 2

[Doug Turner (:dougt)]

no -- the pb window remained open.

Comment 3

[Patrick McManus [:mcmanus]]

try it again after you close the pb window (which has a history in it to inspect, after all).

There are bunch of things that are not particularly PB aware which flush their cache when the last PB window is closed, and it looks like DNS is one of them. So if that did the trick I would at least call it working as designed.

otoh - when you brought this up the other day I feel like I might have seen something in the DNS list that came from PB after closing it.. but I'm not sure, and it went away on me (which might have just been the cache timing out naturally..) so something might be broken.

Comment 4

[Michal Novotny [:michal]]

I tested it and the information remains there after the pb window is closed. There is no action to "last-pb-context-exited" at https://dxr.mozilla.org/mozilla-central/rev/88bebcaca249aeaca9197382e89d35b02be8292e/netwerk/dns/nsDNSService2.cpp#948. I don't understand how the patch in bug 909050 should prevent showing DNS records from pb sessions.

Comment 5

[Valentin Gosu [:valentin] (he/him)]

So, I rechecked, and it still behaves as agreed in bug 909050.
Once the last private browsing window is closed, the DNS cache will be cleared in nsDNSService::Observe()
Note that you must click the Refresh button in about:networking in order to see this change. After this, about:networking should report no DNS cache entries.

Dylan, can you check that this is the behaviour you're seeing?
If you think that there's something more we should do here, please reopen the bug. As noted in bug 909050 comment 0, maybe we should not report anything while a PB window is open, but I still don't think we have a notification for that. Maybe we should add one.

Comment 6

[Michal Novotny [:michal]]

It really doesn't work and I finally know why. It's a regression caused by bug 1161558. When the service is re-initialized in nsDNSService::Observe(), nsDNSService::Shutdown() removes observers but nsDNSService::Init() doesn't add them again because mFirstTime == false.

Comment 7

[Michal Novotny [:michal]]

Attachment: fix

Comment 8

[Valentin Gosu [:valentin] (he/him)]

Comment on attachment 8779908 [details] [diff] [review]
fix

Review of attachment 8779908 [details] [diff] [review]:
-----------------------------------------------------------------

That explains why I wasn't able to reproduce this :)
Thanks for digging into it!

Comment 9

[Patrick McManus [:mcmanus]]

thanks! (please check it in too :)

Comment 10

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/mozilla-inbound/rev/4af8f838049d
Private browsing mode leaks info to about:networking, r=valentin

Comment 11

[Wes Kocher (:KWierso) (Not reading bugmail; email directly if needed)]

https://hg.mozilla.org/mozilla-central/rev/4af8f838049d

Comment 12

[Alexandru Simonca [:asimonca], Release Desktop QA]

This issue is VERIFIED FIXED in Firefox 51.0b9 on Mac OS 10.11.