1900798 - Firefox is freezing if resizing the window during the transition to the blocked dialog for printing operation

Status: VERIFIED FIXED

(Firefox :: Data Loss Prevention, defect)

Description

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

Attachment: Firefox freezing

Found in

• 128.0a1 (2024-06-05)

Affected versions

• 128.0a1 (2024-06-05)

Tested platforms

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

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
• Run the DLP agent in CMD using: .\content_analysis_sdk_agent.exe --user --toblock=.\d{3}-?\d{2}-?\d{4}. --towarn=.warn. --delays=10

Steps to reproduce

1. Navigate to https://en.wikipedia.org/wiki/123456789
2. Open the Print Preview (ctrl+P) and press the “Print” button
3. Wait for the OS notification regarding the DLP agent reviewing data to be displayed and then resize the browser during the transition to the “You’re not permitted..” blocked dialog
4. Observe the behavior

Expected result

• Firefox is not freezing after resizing the window during the transition to the “You’re not permitted..” blocked dialog

Actual result

• Firefox is freezing, causing the entire desktop to become unresponsive

Regression range*

• We suspect that bug 1899714 introduced this issue, but we cannot be sure due to the same bug. This is happening before bug 1898718 as well.

Additional notes

• See the attached video
• The issue is fixed after closing Firefox from Task Manager
• This is only reproducing for the printing operation - and only when resizing the window during the transition to the blocked dialog
• Not reproducing when resizing the window and printing operation is allowed
• Not reproducing for blocked paste / upload operation

Comment 1

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

Changing the severity to S3 as I accidentally selected S4.

Comment 2

[Greg Stoll :gstoll]

Attachment: Bug 1900798 - go back to async "DLP blocked" dialog for print preview r=#dlp-reviewers!

A new attempt to fix these problems - always use asynchronous dialogs, but in the print preview case show the "DLP blocked" dialog on the original browsingContext that displayed the print preview dialog (since the dialog itself is about to close)

Comment 3

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

Set release status flags based on info from the regressing bug 1899714

Comment 4

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/99ddc4351882
go back to async "DLP blocked" dialog for print preview r=dlp-reviewers,handyman

Comment 5

[pstanciu]

https://hg.mozilla.org/mozilla-central/rev/99ddc4351882

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.
• If no, please set status-firefox128 to wontfix.

For more information, please visit BugBot documentation.

Comment 7

[Greg Stoll :gstoll]

No (although we will be uplifting to ESR next cycle)

Comment 8

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

Verified as fixed using Firefox Nightly 129.0a1, build ID 20240613215041, using Windows 11. Firefox is no longer freezing after resizing the window during the transition to the “You’re not permitted..” blocked dialog.

Comment 9

[Greg Stoll :gstoll]

Attachment: Bug 1900798 - go back to async "DLP blocked" dialog for print preview

A new attempt to fix these problems - always use asynchronous dialogs, but in the print preview case show the "DLP blocked" dialog on the original browsingContext that displayed the print preview dialog (since the dialog itself is about to close)

Original Revision: https://phabricator.services.mozilla.com/D212815

Comment 10

[Phabricator Automation]

esr128 Uplift Approval Request

• User impact if declined: Firefox will hang when resizing the print window with DLP active
• Code covered by automated testing: no
• Fix verified in Nightly: yes
• 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: just affects DLP
• String changes made/needed: no
• Is Android affected?: no

Comment 11

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-esr128/rev/9d89486fff1d

Comment 12

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

Verified as fixed on Firefox 128.3.0esr, build ID 20240911002735 (from Treeherder), using Windows 10/11.