Insmod permission error when being ran from systemd service

Ask Fedora Ask in English
1

I’m trying to set up a systemd service that runs a script that calls insmod on a kernel module.

When I try running it, I get: insmod: ERROR: could not insert module <module>.ko: Permission denied.

If I run the script that calls insmod as sudo, it works just fine. It only fails when running the service. The service is in /etc/systemd/system so it’s not a local user service.

It’s just a oneshot that runs the script with ExecStart . Anyone got a clue why insmod specifically has issues running in an authenticated systemd service?

1 Like
2

Can you post the service and the script?
Thanks

3

Here’s the script, and here’s the service. I’ve tried writing it a couple of different ways (e.g. not compiling it at all, just loading the module) and it still fails. Running the script manually works fine.

Thanks!

4

Here’s what’s being compiled in case you want to test it:

5

Make sure to disable Secure Boot in BIOS/EFI and then build the modules with DKMS:

sudo dnf install git dkms kernel-devel openssl
sudo git clone https://github.com/hannesmann/gcadapter-oc-kmod.git \
/usr/src/gcadapter-oc-git
sudo sed -e "/^MAKE/d;/^CLEAN/d
/^DEST_MODULE_LOCATION/s|/extramodules|/extra|" \
/usr/src/gcadapter-oc-git/packaging/arch/dkms.conf \
| sudo tee /usr/src/gcadapter-oc-git/dkms.conf > /dev/null
sudo dkms add gcadapter-oc/git
sudo systemctl restart dkms.service
sudo tee /etc/modules-load.d/gcadapter-oc.conf << EOF > /dev/null
gcadapter_oc
EOF
sudo systemctl restart systemd-modules-load.service
3 Likes
6

Thanks for that! I used to do something like that before but the I had was that every time there was a kernel update I had to recompile for that kernel version. This seems to work. Still curious as to why insmod failed but this is better!

1 Like
7 
journalctl --no-pager -b -g "avc.*insmod"
1 Like