1918028 - Pasting warning text again after 5 seconds after the first scan was canceled makes the page unresponsive

Status: VERIFIED FIXED

(Firefox :: Data Loss Prevention, defect)

Description

[Alexandru Trif, Desktop Test Engineering [:atrif] [PTO 18-22]]

Attachment: dlp_unresponsive.gif

Found in

• 132.0a1

Affected versions

• 132.0a1 (2024-09-10)

Tested platforms

• Affected platforms: Windows 11, Windows 10
• Unaffected platforms:macOS 12, Ubuntu 22

Preconditoins

• 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. Open Wikipedia.
2. Copy warning text from an external program
3. Paste the warning text inside the search area.
4. Click on Cancel and wait ~5 seconds.
5. Paste the text again.

Expected result

• The scan is happening again.

Actual result

• Page becomes unresponsive.

Regression range

• This happens after bug 1915350 was fixed. I will set bug 1912384 as the regressor, please change it if this is incorrect.

Additional notes

• Attached a screen recording.
• Another set of steps:

1. Copy warning text and paste it inside the Wikipedia search.
2. Click the cancel button, and repeat both steps 3 more times.

• Silent crashes appear inside the crash reporter like https://crash-stats.mozilla.org/report/index/342550ea-2f0b-47c6-a692-7c3120240911 or https://crash-stats.mozilla.org/report/index/7557748a-6e22-45e0-8872-253160240911.
• The issue reproduces on Google Docs as well. If other Google Docs pages are opened in different tabs, they become blank/ unresponsive and do not recover until closed.
• I will mark this with [fidefe-quality-foundation?] even if this issue may be an edge case because of silent crashes and the behavior on Google Docs/ One drive which will make all Google Docs/ Onedrive tabs blank or unresponsive if this issue is reproduced there.

Comment 1

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

Set release status flags based on info from the regressing bug 1912384

:gstoll, since you are the author of the regressor, bug 1912384, could you take a look?

For more information, please visit BugBot documentation.

Comment 2

[Greg Stoll :gstoll]

Yeah, I can reproduce this, will investigate.

Comment 3

[Greg Stoll :gstoll]

This only seems to reproduce with WARN results, not ALLOW or BLOCK.

Comment 4

[Greg Stoll :gstoll]

I think this is because we store the WARN result in the cache even if the scan was cancelled. We rely on not storing WARN results in the cache, otherwise things like bug 1915350 happen.

Comment 5

[Greg Stoll :gstoll]

Attachment: Bug 1918028 - avoid potential future hang when cancelling Content Analysis WARN response r=#dlp-reviewers!

Comment 8

[Pulsebot]

Pushed by [e-mail]:
https://hg.mozilla.org/integration/autoland/rev/88be53726640
avoid potential future hang when cancelling Content Analysis WARN response r=dlp-reviewers,handyman

Comment 9

[Norisz Fay [:noriszfay]]

https://hg.mozilla.org/mozilla-central/rev/88be53726640

Comment 10

[Alexandru Trif, Desktop Test Engineering [:atrif] [PTO 18-22]]

Verified fixed with Firefox 132.0a1 (20240918041351) on Windows 10x64 and 11. The browser no longer hangs after pasting warning text again after 5 seconds after following steps from comment 0.

Comment 11

[Greg Stoll :gstoll]

Attachment: Bug 1918028 - avoid potential future hang when cancelling Content Analysis WARN response r=#dlp-reviewers!

Don't cache canceled CA results, as this can cause particular problem with WARN responses,
which shouldn't be in the cache.

Original Revision: https://phabricator.services.mozilla.com/D221880

Comment 12

[Phabricator Automation]

esr128 Uplift Approval Request

• User impact if declined: possible hang in DLP when cancelling a WARN response and then quickly doing another DLP request with the same data
• 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, will be covered as a part of the general DLP test plan
• Risk associated with taking this patch: low
• Explanation of risk level: minor change to DLP
• String changes made/needed: no
• Is Android affected?: no

Comment 13

[Pulsebot]

https://hg.mozilla.org/releases/mozilla-esr128/rev/1236883f5c9b

Comment 14

[Alexandru Trif, Desktop Test Engineering [:atrif] [PTO 18-22]]

Verified fixed with Firefox 128.3.0esr (20240923123820) on Windows 10x64. The browser no longer hangs after pasting warning text again after 5 seconds.