Does ClamXAV crash an M1 Mac?

Last year I reported that Macs running the new M1 chipset were crashing when running ClamXAV antivirus. At the time the cause wasn’t known, but there was a temporary workaround. A year on and things have changed, although the root cause is still to be fixed. So what can you do now to prevent a ClamXAV crash on an M1 Mac? Find out below.

Why does ClamXAV crash an M1 Mac?

Users running ClamXAV on M1 Macs were seeing occasional reboots, each of which reported an error similar to this:

panic(cpu 4 caller 0xfffffe00184dd618): "uipc_send connected but no connection?"

This is what’s known as a “kernel panic”. They can be identified by the screen going pink, followed by a sudden shut down and restart.

It was found that turning off ClamXAV’s “Sentry” scanning resolved the problem. However, Sentry is used to scan files in real-time – with this deactivated, you are relying on timed scans or performing them ad-hoc.

What did ClamXAV say about this?

At the time, the company issued the following statement to The Big Tech Question:

We believe that this can only be an issue with Apple’s code and not our own, as we don’t ship any code that runs at the kernel level. We would like to reassure customers that we are in close contact with Apple for the purposes of diagnosing and fixing this issue.

The company also stated that this was only affecting a small minority of customers.

What is the latest? Is this fixed?

Sadly, it’s still not fixed. ClamXAV told us:

We’ve continued working closely with Apple on the issue, and they’ve identified a potential solution, but they have not shared with us a timeline for releasing it. 

ClamXAV put out a message in November of last year stating that updating your OS to 12.0.1 “may help”, but later retracted this in favour of a new workaround.

Is there an issue on M2 Macs?

ClamXAV have told us that they are still investigating this but, so far, have had no reports of it occurring on M2 systems.

What is the new workaround?

First of all, if you previously turned off Sentry, you should be fine to turn that back on now. Here’s how:

1. Open up ClamXAV
2. Click on Preferences in the top-right of the window
3. Now click on the Advanced tab
4. Tick Enable Sentry background monitor

This is the current workaround, as detailed on the ClamXAV website:

1. Update to ClamXAV 3.4 (or newer)
2. Go to System Preferences > Security & Privacy
3. Open the Privacy tab, and scroll down to Full Disk Access
4. Remove the item marked uk.co.canimaansoftware.ClamXAV.HelperTool
   
   (NB: it’s not enough just to untick it. You must select it and press the [-] button at the bottom of the list)
5. Launch ClamXAV again and follow the prompts to enable Full Disk Access
6. Ensure uk.co.canimaansoftware.ClamXAV.HelperTool has reappeared, and is ticked
7. Restart your computer (don’t skip this step!)

When trying this myself I found that point 5 didn’t occur – I had to reboot my Mac first and, after launching ClamXAV, I then got a prompt. ClamXAV have told me that this is sometimes the case.

Fingers crossed, that should help. This doesn’t appear to turn off any functionality and is merely deleting something which is then automatically recreated. However, as soon as anything further changes, I’ll provide an update.