11.5.2 didn't fix the issue for me. Still panic(cpu 5 caller 0xffffff801a49fc36): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff938facc000, prot:zero) On Mac OS version: 20G95 Are you sure you are facing the same kernel panic @paabloop? Only things so far that fix it for me are: - Connect displays via HDMI; - Beta of Monterey; - Turning off DP 1.2 on my Dell Monitor

You are amazing @scarvalhojr! That fixes the problem for me. At least. So far I'm unable to crash my system after disabling DP 1.2 on the monitor. I had DP 1.2 enabled in the hope one day macOS would support MST Daisy Chaining so that I only need to switch the input on 1 of my displays to switch to a different system. https://discussions.apple.com/thread/7363807 But I've given up on that hope. If they are not even accepting a Kernel Panic to be something wrong with macOS how the ... will they be able to support something as MST Daisy Chaining.

Still crashes :(

This is a great suggestion. Will try this after the 11.5 Beta 5 test

I'll test this soon™

https://www.macrumors.com/how-to/install-macos-monterey-public-beta/ But please be aware, this version of macOS is not stable on a lot of other fronts. What I did is create a separate partition with the disk utility and then just test if it's fixed. I'm not working on the beta. Connecting displays via HDMI also seems to resolve the issue. That's more practical than switching to a beta.

You have gotten further with support than me. My senior adviser claims he's not able to get through to engineering (engineering says: it's 3rd party hardware fault, not ours). Please note, the fix appears to be incoming, but only with Monterey. At least, the last beta didn't have the issue anymore. But 1 year ago I was in a similar situation (crashes in Catalina, would be fixed in Big Sur), but then Apple at least accepted the fact that it was an issue on their end. This time I've not been able to get that statement from Apple.

Don't have a mouse jiggle. But I know I can trigger this crash by just turning my external display off and on again. So I guess it will happen for some after waking from sleep. I personally use: https://apps.apple.com/nl/app/sleep-control-center/id946798523?l=en&mt=12 to prevent my system from sleeping at moments that I don't want it. But it's highly troubling to me that a system can crash by just turning an external display off and on again.

Still crashes :(

Interesting, your off value is different then what most of the people in this thread seem to have. You have off 1584, while most have off: 1672. Not sure what this difference means though :(

Your crash looks a little different. [kext.kalloc.2048]: element modified after free (off:1672, vs [data.kalloc.4096]: element modified after free (off:1184, So I'm not sure if you are experiencing the same issue.

With HDMI as well? What's the reproduction path then? I was not able to reproduce the issue with HDMI :( But that's because my reproduction path is: turn off display, turn it on again, see if it's not getting a signal from the Mac, if that's the case: turn it off and on again: success (a crash)! With HDMI turning a display off doesn't send a signal to macOS, so the trigger for the error is not there.

So far indeed unable to crash Monterey beta 2. I've been able to loose display to one of the 2 external displays, turning it off and on again doesn't restore it in macOS, so guess I'll need to reboot to get that one to work again (disconnecting dock and reconnecting was enough to restore it). While turning displays off and on, my MacBook screen behaves weird. It seems to turn off and on again multiple times. And my mouse cursor is very unresponsive while this is happening. But at least no more crashes.

11.5 Beta 3 is still affected: panic(cpu 0 caller 0xffffff8013e98a66): [kext.kalloc.2048]: element modified after free (off:1672, val:0xfffffffe00000000, sz:2048, ptr:0xffffff93880aa800, prot:zero) Mac OS version: 20G5042c

Installing 12 Beta 2 now, will install 11.5 beta 3 on different partition after that