Tracking issue for apps that start using 100% CPU due to how sockets are closed by a network extension

[Chinaski1]

The list of problematic apps:

1. Adobe Creative Cloud
2. Mail.app
3. netbiosd

The issue explanation is here: https://developer.apple.com/forums/thread/681135

Since the original report we implemented a workaround that mitigates the issue, but there's still a small possibility of that happening.

Original report:

• OS version: 11.3 Beta (20E5224a)
• AdGuard Version: 2.5.3.955 release (CL-1.7.200)
• Filtering method: Network extension
• Adobe Creative Cloud version: Version 2.4.0.41 (2.4.0.41)

Original appeal

[akiltopu]

Any progress?

[sfionov]

It is not 100% reproducable but we've been able to reproduce it and are now trying to find the reason of this behaviour (yet another Apple bug or API misusage).

[marcellosilvestri]

Thanks @sfionov is there any ETA? I am unable to use Adguard as of now until the issue will be fixed - unless there's any workaround? Also, do you know if this is happening only with the Mac App, or does it still happen even if I just have the Chrome plugin?

[Chinaski1]

Hi all!

@wiredmark @akiltopu

I would like to clarify some information.
Please specify if you are using system proxy settings? (System preferences -> Network -> Advanced -> Settings)

[marcellosilvestri]

Hi @Chinaski1, nope, nothing is flagged in that screen

[sfionov]

This happens because of Apple's misbehaviour, and a way network apps processes socket errors. macOS doesn't indicate read error on sockets that existed before starting AdGuard protection - only when they try to write something. That confuses apps a lot.

This is also reproducible with Apple SSH connected to non-standard port (because standard port is excluded in AdGuard).

Reported to Apple: FB9125326

[sfionov]

There's no workaround right now but killing CPU-consuming process will help.

[sfionov]

Also reported to Apple developer forums: https://developer.apple.com/forums/thread/681135

[Horizon531]

I've been having this issue for years and had no idea adguard was the cause.

[ameshkov]

To be precise the bug is Apple's :(

Since v2.8 we implemented a workaround that should've mitigated it, but there's still a small possibility of that happening.