I'm having the exact same issue on my RPi 3. I've been using the Pi for a very long time now and never had an issue. But since last week I updated the OS to the latest Raspberry OS and the Pi is now running as a K3s master node. Since then the Pi keeps crashing like this. I've having a lot of network traffic, way more than it had before it was used as a k3s master node.
About 2 days ago I tried the rpi-update which Christopher provided, and since then the Pi is running without any crashes (yet). Almost 48 hours already, where before it wasn't able to run 24 hours straight.
I'm having the exact same issue on my RPi 3. I've been using the Pi for a very long time now and never had an issue. But since last week I updated the OS to the latest Raspberry OS and the Pi is now running as a K3s master node. Since then the Pi keeps crashing like this. I've having a lot of network traffic, way more than it had before it was used as a k3s master node.
About 2 days ago I tried the rpi-update which Christopher provided, and since then the Pi is running without any crashes (yet). Almost 48 hours already, where before it wasn't able to run 24 hours straight.