I get this every couple minutes in my journalctl, and it seems to be affecting my RPi.
I’ve already checked the delays from the ntp servers, and it seems to be accurate. If I check the time at any current moment (which should be off every few minutes) it seems to be accurate.
Hard to say as it’s only one log. What else has been installed on the system?
Was this you or a hacker?
May 06 20:00:41 Vader-Grumbole sshd[857]: Accepted publickey for osmc from 5.135.156.87 port 53032 ssh2: RSA SHA256:wJdFGpgbKPljTyPlneAlToE/FJfsZsafFw3zkWgTywU
That was me. I noticed I’ve been getting connections from hackers though, so I changed the external port.
I run oscam, tvheadend, and that’s it pretty much.
Is it possible that this occurs because I downgraded the kernel after upgrading to the April release?
As Sam said, we need a bit more to go on – preferably a full set of logs.
Your system journal is a bit “busy” with kernel oopses, hack attacks and a bunch of other stuff. I’ve never seen those multiple messages myself but a quick search suggests that they might be caused by a(nother) process running on your system.
If this system has ever been compromised on any port, simply changing the port does not make the system magically secure. The system needs a reinstall.