OpenSSL corruption broke pretty much whole system

[McFox]

Hello.

This is not really an actual question, but more like a FYI if someone else happens to run into similar problems.

So yesterday at work, I noticed I couldn't ssh my Raspberry Pi (2.0). I figured it had just frozen, so when I got home I pulled the plug and put it in again. I got a few errors on start, and most particularly, Kodi didn't start. After upgrading the system I got a ton of errors from systemd during boot, and half of my services just wouldn't start. sshd, nginx, ntpd, etc. being among those. Also, pacman -Syu didn't work, it just crashed with a segmentation fault. All other pacman operations I tried did work though. Because ssh didn't work, I grabbed my physical keyboard and started investigating.
I did pacman -S base, just to reinstall all base packages in case one of those would've been broken, but that didn't help. I then noticed it complaining about filesystem errors on mmcblk0p2, which is the root device. I didn't find a way to run fsck on it locally, so I took the sd card out and put it in my laptop (which is running the normal version of Arch), took a full dd-backup of the root partition and ran fsck. It discovered a whole bunch of errors and I let it fix them. Then I put the card back into the Pi, same result as before, but without the filesystem errors. I tried starting sshd manually, it just said "Crash: core dumped". Then I tried nginx, and that's where I found the problem. Journalctl said something about corruption in libcrypto.so.10.0 (or whatever the version might have been), so I googled which package that belonged to. It was openssl, reinstalled that, and boom! Everything works again...

So apart from maybe helping someone out in case of a similar breakdown, I was wondering wtf could've caused this? The machine had crashed while I was away, and after a reboot some services (Kodi and Sickrage among others) wouldn't start. sshd and pacman -Syu still worked at this point. So I upgraded my system, and after that openssl broke for whatever reason. I'd understand if the machine had crashed in the middle of upgrading the package or something, but that didn't happen...

I don't know what specs to post, but my Pi is running Arch Linux ARM with all the latest packages, with kodi-rbp, sickrage, couchpotato, nginx, transmission... That's about it. The OS is installed on a 16gb SanDisk UHS-1 microsd and I have a 4tb usb harddrive connected to it at all times.