Re: Cramfs: "unable to handle kernel paging request" when reading a file from a fuzzed FS image

From: Nicolas Pitre
Date: Sun Oct 28 2018 - 23:43:13 EST

On Sun, 28 Oct 2018, Anatoly Trosinenko wrote:

> Hello,
> When reading a file from a fuzzed cramfs image, unhandled kernel
> paging request occurs.

Hmmm... It doesn't show up on my test system.

> How to reproduce with kvm-xfstests:
> 1) Checkout the v4.19 tag, copy x86_64-config-4.14 to .config, perform
> `make olddefconfig`
> 2) Enable Cramfs in the config, then compile
> 3) In the `kvm-xfstests shell` perform:
> root@kvm-xfstests:~# mount /vtmp
> root@kvm-xfstests:~# mount /vtmp/cramfs.img /mnt

How do I populate /vtmp? Mine is empty at this point. I imagine I should
put the cramfs image somewhere on the host, but I'm not that familiar