1918047 - Google/OneDrive Documents become blank during DLP scan in another document

Status: RESOLVED WONTFIX

(Firefox :: Data Loss Prevention, defect)

Description

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

Attachment: Docs from other tabs become blank during DLP scan

Found in

• 132.0a1 (2024-09-10)

Affected versions

• 132.0a1
• 131.0b4
• 128.2.0esr

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

Tested platforms

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

Steps to reproduce

1. Go to https://drive.google.com/drive/home and sign in
2. Copy any text from an external program / random webpage
3. Open 2 Google Docs in separate tabs and paste the copied content in the first Google Doc
4. While the scan is still in progress, switch to the second Google Doc tab and observe the behavior

Expected result

• The second document is visible and functional while the scan is performed on the first document

Actual result

• The second document’s tab becomes blank with a loading spinner, until the scan is complete

Regression range

• Most likely not a regression. This is happening in 128.2esr.

Additional notes

• Also reproducing for One Drive Documents (Word / PowerPoint / OneNote docs)
• The document is functional after the scan in complete
• See the attached video

Comment 1

[Greg Stoll :gstoll]

Thanks for the video!

Because of the way clipboard DLP is architected, we expect this to happen for tabs that are in the same process - looking at the video I can see that the "pid" on the tabs that are blank are the same as the one that is doing the DLP, which means they are in the same process.

However, most of the time we will use a round-robin strategy so the first 8 tabs on the same site will go into different processes, so we think this won't affect most people. I'm curious how you ended up in this state - have you changed the pref value for dom.ipc.processCount? Or is this an ASAN build or something?

Comment 2

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

(In reply to Greg Stoll :gstoll from comment #1)

Thanks for the video!

Because of the way clipboard DLP is architected, we expect this to happen for tabs that are in the same process - looking at the video I can see that the "pid" on the tabs that are blank are the same as the one that is doing the DLP, which means they are in the same process.

However, most of the time we will use a round-robin strategy so the first 8 tabs on the same site will go into different processes, so we think this won't affect most people. I'm curious how you ended up in this state - have you changed the pref value for dom.ipc.processCount? Or is this an ASAN build or something?

Hi Greg,
I did not change the pref value for dom.ipc.processCount. Looking in about:config it seems that the default value is '8'.
And regarding the build, it is not an ASAN build. For both Nightly and Beta I am using the official builds from archive (https://archive.mozilla.org/pub/firefox/candidates/131.0b4-candidates/build1/win64/en-US/).

Comment 3

[Greg Stoll :gstoll]

Huh, that's weird. If you go to about:config and filter to modified preferences are there any that start with "dom.ipc." or "fission." that are changed?

Comment 4

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

Attachment: Screenshot 2024-09-11 171303.png

It seems that there are no modified prefs that start with 'dom.ipc' or 'fission'. Let me know if I can provide more details!

Comment 5

[Greg Stoll :gstoll]

Interesting - it seems like clicking "Open in New Tab" (or middle-clicking) on Google Docs will open links in the same process, but this doesn't seem to happen other places. I'm going to ask around to see if this is intended or not.

But either way, this is just a limitation of how DLP clipboard works so I'm going to close this bug. Thanks!