USB Memory stick all users rw permissions

I have a Colibri VF50 running Linux 2.5. When a USB memory stick is plugged into the USB port, it mounts automatically. However, only root can read and write to it. How can I allow any user to read and write to the memory stick. Ideally without being able to execute any programs on the memory stick. It would be nice to configure this from open embedded.


The /etc/udev/rules.d/automount.rules udev rule mounts all fat partitions with permissions set to root:disk.
So one way would be make your regular user member of the ‘disk’ group.

I guess one could modify the /etc/udev/scripts/ script used to set the file permissions to not have the executable rights. However I’m unsure if a user with rw permissions isn’t allowed to add the executable bit by himself.

For file systems which actually support permissions the file systems root will be mounted for root:root, however any file and directory will have the access rights as set in the file system.


Your kernel is 2.5? If yeah, the kernel is not supported by udev yet.

If greater than 2.6, success! Just add the rule as above to any group for everyone.

If the kernel is 2.5 will have to create rules for handling hotplug with mount and umount.

Cleiton Bueno

Blog | B2Open

I don’t quite understand what you are referring to, the kernel in V2.5 is udev capable…

In V2.5 Beta 1 systemd did not allow udev to mount “globally”, hence rendering automount basically unusable. But this has been resolved with V2.5 Beta 2 and later:

@stefan.agner I guess @cleitonbueno meant 2.5 means the historical Linux 2.5 kernel. However 2.5 for us is just an arbitrary BSP version number and not directly related to the Linux kernel version. The Linux kernel version actually depends on the resp. module as outlined in the following article on our developer website.

@marcel.ziswiler: Oh I see. Well, Vybrid on Linux 2.5 would be interesting, also 2.5 wasn’t even stable :slight_smile:

@marcel.ziswiler Got it.
A rule in udev should solve then.