1964606 - Webpage becomes unresponsive during background scan and allowed content is still pasted after canceling the scan

Status: VERIFIED FIXED

(Firefox :: Data Loss Prevention, defect)

Description

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

Attachment: unresponsive.mp4

Found in

• 139.0b4

Affected versions

• 139.0b4
• 140.0a1 (2025-05-05)

Tested platforms

• Affected platforms: Windows 10, Windows 11
• Unaffected platforms: Ubuntu, macOS

Preconditions

• Download the DLP test assets from https://drive.google.com/file/d/1yjqVRuxdKV3WnO7D2wzMgDXBuYBxUgVw/view
• Create a distribution folder inside the Firefox folder and paste the policies-1.json to it and then rename it to policies.json
• DLP Agent is running: .\content_analysis_sdk_agent.exe --user --toblock=.*\d{3}-?\d{2}-?\d{4}.* --towarn=.*warn.* --delays=10

Steps to reproduce

1. Navigate to any webpage (e.g. wikipedia) and paste a random string into a text field
2. Press the "Cancel" button in the "Scan in progress" dialog before the scan completes
3. Interact with the webpage and observe the behavior

Expected result

• The webpage should remain responsive after canceling the scan
• The content should not be pasted after the agent finishes the scan in the background, as the scan was canceled

Actual result

• The webpage becomes unresponsive until the agent completes the scan in the background
• The allowed content is still pasted after the agent completes the scan in the background, even though the scan was canceled

Regression range

• Most likely a regression from bug 1963360 since 139.0b3 is not affected

Additional notes

• Attached a screen recording.
• Not reproducing for uploads or for drag and drop actions

Comment 1

[BugBot [:suhaib / :marco/ :calixte]]

:gstoll, since you are the author of the regressor, bug 1963360, could you take a look? Also, could you set the severity field?

For more information, please visit BugBot documentation.

Comment 2

[Greg Stoll :gstoll]

Clicking Cancel isn't cancelling, because the aUserActionId in the finally clause is wrong. Not sure why that is yet.

Comment 3

[Greg Stoll :gstoll]

Attachment: Bug 1964606 - make cancelling Content Analysis request from the busy dialog work r=#dlp-reviewers

The fix to bug 1963360 broke cancelling in the dialog. This is a small
fix but I also added a few tests around the busy/cancel dialog, which
will hopefully prevent these kinds of regressions in the future.

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/262426dea56a
make cancelling Content Analysis request from the busy dialog work r=dlp-reviewers,haik

Comment 5

[Cosmin Sabou [:CosminS]]

https://hg.mozilla.org/mozilla-central/rev/262426dea56a

Comment 6

[BugBot [:suhaib / :marco/ :calixte]]

The patch landed in nightly and beta is affected.
:gstoll, is this bug important enough to require an uplift?

• If yes, please nominate the patch for beta approval.
  • See https://wiki.mozilla.org/Release_Management/Requesting_an_Uplift for documentation on how to request an uplift.
• If no, please set status-firefox139 to wontfix.

For more information, please visit BugBot documentation.

Comment 8

[Greg Stoll :gstoll]

Attachment: Bug 1964606 - make cancelling Content Analysis request from the busy dialog work r=#dlp-reviewers

The fix to bug 1963360 broke cancelling in the dialog. This is a small
fix but I also added a few tests around the busy/cancel dialog, which
will hopefully prevent these kinds of regressions in the future.

Original Revision: https://phabricator.services.mozilla.com/D248103

Comment 9

[BugBot [:suhaib / :marco/ :calixte]]

Copying crash signatures from duplicate bugs.

Comment 10

[Phabricator Automation]

firefox-beta Uplift Approval Request

• User impact if declined: DLP users cannot cancel requests
• Code covered by automated testing: yes
• Fix verified in Nightly: no
• Needs manual QE test: no
• Steps to reproduce for manual QE testing: n/a
• Risk associated with taking this patch: low
• Explanation of risk level: simple JS change that only affects Content Analysis
• String changes made/needed: no
• Is Android affected?: no

Comment 11

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-beta/rev/09d4f733e4f4

Comment 12

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

Verified as fixed on Firefox Nightly 140.0a1 (2025-05-08), using Windows 11. The webpage remains responsive after canceling the scan and the content is also not pasted after the agent finishes the scan in the background.
Waiting for 139.0b6 build to verify the fix there as well.

Comment 13

[Bianca Hidecuti, Desktop Test Engineering [:bhidecuti]]

Verified as fixed using Firefox 139.0b6 on Windows 11, as well.