Most programs suddenly segfault

Question

I'm having a strange occurrence on my Raspbian Raspberry Pi, as most programs are now segfaulting before they even start:

user@raspberrypi:~ $ sudo -s
Segmentation fault
user@raspberrypi:~ $ ssh -vvv localhost
Segmentation fault
user@raspberrypi:~ $ sudo reboot
Segmentation fault
user@raspberrypi:~ $ sudo apt update
Segmentation fault
user@raspberrypi:~ $ htop
htop 2.0.2 aborting. Please report bug at http://hisham.hm/htop
(...)

Some simple things still work:

user@raspberrypi:~ $ touch abc
user@raspberrypi:~ $ ls
abc

My uname -a is Linux raspberrypi 4.9.41-v7+ #1023 SMP Tue Aug 8 16:00:15 BST 2017 armv7l GNU/Linux, and free returns

              total        used        free      shared  buff/cache   available
Mem:           927M         40M         31M        9.1M        855M        816M
Swap:           99M         13M         86M

I can't reboot gracefully since sudo and su both die. This session was open before this started, but I can't open new ssh sessions into the box either.

I'll try to pull the plug and turn it on again, but what could be causing this? I did an apt upgrade earlier, but it seems like this started later; I have no idea what other culprits may be.

Thanks!

Answer 1

I've had the same and a number of times (I don't remember how many, but at least two). I eventually came to consider this a fatal situation. The only thing that worked for me was a completely new installation. What I blame for this is the magnetic card. That's only my guess, I don't have any arguments. Well, I might have one. This always happened after my Pi had spent a long idle time in a drawer. So my pessimistic advice is to backup what might still be of value and start anew. But if I were you, I'd wait for other answers before I proceed, as I'm not that experienced nor knowledgable.