Closed Bug 1636554 Opened 5 years ago Closed 5 years ago

Turning on DoH by default causes caching of incorrect redirects

Categories

(Core :: Networking: DNS, defect)

Product:
Core
Component:
Networking: DNS
Version:
76 Branch
Type:
defect

Tracking

()

Status:
RESOLVED DUPLICATE of bug 1544233

People

(Reporter: rob, Unassigned)

Details

User Agent: Mozilla/5.0 (X11; Linux x86_64; rv:76.0) Gecko/20100101 Firefox/76.0

Steps to reproduce:

  • I was just using my browser as normal, and noticed my personal wiki (which I run on personal.wiki, a private IP in my /etc/hosts) stopped syncing
  • I looked at the network tab in developer tools, and noticed a 302 redirect to www.personal.wiki and then some CORS preflight OPTTIONS requests
  • I noticed that personal.wiki wasn't resolving to my private IP by hovering over the requests, and when I suspected DoH and opened a new tab to check about:config, I was greeted by the DoH doorhanger and clicked "Disable"
  • I tried to visit personal.wiki in a new tab

Actual results:

Firefox cached the 302 redirect from the DoH-driven resolution, and brought me to www.personal.wiki

Expected results:

Firefox should have respected my /etc/hosts entries - see https://bugzilla.mozilla.org/show_bug.cgi?id=1544233

Also for expected results - Firefox should have not followed the cached redirect, which was fetched from another IP address. I don't have a good solution for this - things like DNS-based load balancing of course complicate this - but I just thought it should be on the radar!

Because this bug's Severity is normal and has not been changed, and this bug's priority is -- (none,) indicating it has has not been previously triaged, the bug's Severity is being updated to -- (default, untriaged.)

Severity: normal → --

Hi Rob,

Thank you for your report.

Let's assign this issue to the Networking: DNS component and hopefully someone with more knowledge in this area will look over it.

In the meantime, can you please download Firefox Nightly and check if you have the same result? You can download it from here: https://nightly.mozilla.org/

Regards,
Virginia

Component: Untriaged → Networking: DNS
Product: Firefox → Core

Hi Rob, I suggest using a different domain for your personal wiki - one that does not exist on the public DNS.
I suggest personal.test, or something like that, so that DNS over HTTPS can't resolve it so we fall back to using /etc/hosts.

You should be able to force-refresh the wiki with Ctrl-Shift-R.

Status: UNCONFIRMED → RESOLVED
Closed: 5 years ago
Resolution: --- → DUPLICATE
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