1953481 - MOZ_ASSERT_UNREACHABLE("missing canceled response action") with TimeoutResult=1 when requests time out

Status: RESOLVED FIXED

(Firefox :: Data Loss Prevention, defect)

Description

[Greg Stoll :gstoll]

STR:

• Run the sample DLP agent with --delays=10
• Launch Firefox
• Set browser.contentanalysis.agent_timeout to 5
• Set browser.contentanalysis.timeout_result to 1
• Restart Firefox
• Navigate to https://mdn.github.io/learning-area/html/forms/file-examples/simple-file.html
• Click "Browse..." and select three files that wouldn't be blocked by the DLP agent
• When the WARN dialogs pop up, click "Use content"

A few seconds later the MOZ_ASSERT_UNREACHABLE will be hit.

Comment 1

[Alexandru Trif, Desktop Test Engineering [:atrif]]

Attachment: 1953481.gif

Hello Greg! Unfortunately, I cannot reproduce this crash with Firefox 138.0a1 (2025-03-12). Am I missing something? Attached a screen recording.

Comment 2

[Greg Stoll :gstoll]

Hi Alexandru! I think you are hitting this problem - at the very end of the agent log you can see that it is receiving an acknowledgment with final action <Unspecified>, which is an indication that this is probably happening. The crash is actually a MOZ_ASSERT(), which will only crash in a debug build - were you trying with a debug build? Thanks!

Comment 3

[Alexandru Trif, Desktop Test Engineering [:atrif]]

(In reply to Greg Stoll :gstoll from comment #2)

Hi Alexandru! I think you are hitting this problem - at the very end of the agent log you can see that it is receiving an acknowledgment with final action <Unspecified>, which is an indication that this is probably happening. The crash is actually a MOZ_ASSERT(), which will only crash in a debug build - were you trying with a debug build? Thanks!

Oh, I was on a normal build. Thank you for the explanation, I didn't know that MOZ_ASSERT() happens on debug builds and I thought this was a crash.

Comment 4

[Greg Stoll :gstoll]

Attachment: Bug 1953481 part 1 - avoid asserting when hitting timeout with TimeoutResult=warn r=#dlp-reviewers!

The code was expecting that once we get a response from the agent and
we are going to auto-acknowledge there should be an entry in
mUserActionIdToCanceledResponseMap. This was not the case if we were
waiting for a warn response from the user. Now we check for that case
and early return.

Comment 5

[Greg Stoll :gstoll]

Attachment: Bug 1953481 part 2 - refactor some Content Analysis tests to share timeout logic r=#dlp-reviewers!

Also removing a function that nothing was using anymore.

Comment 6

[Greg Stoll :gstoll]

Attachment: Bug 1953481 part 3 - add some Content Analysis WARN tests r=#dlp-reviewers!

We didn't have any of these previously, so I added a few simple use
cases and a few that were previously triggering the MOZ_ASSERT_UNREACHABLE()
addressed in this bug.

Comment 7

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/e6de35b0e9d6
part 1 - avoid asserting when hitting timeout with TimeoutResult=warn r=dlp-reviewers,handyman
https://hg.mozilla.org/integration/autoland/rev/48f39a85bb61
part 2 - refactor some Content Analysis tests to share timeout logic r=dlp-reviewers,handyman
https://hg.mozilla.org/integration/autoland/rev/c97516598534
part 3 - add some Content Analysis WARN tests r=dlp-reviewers,handyman

Comment 8

[Serban Stanca [:SerbanS]]

https://hg.mozilla.org/mozilla-central/rev/e6de35b0e9d6
https://hg.mozilla.org/mozilla-central/rev/48f39a85bb61
https://hg.mozilla.org/mozilla-central/rev/c97516598534