I'm having permissions problems getting to files on a USB drive in #Linux. Not sure what to do here.

Specifically, this is a USB boot drive for a Raspberry Pi 4 which no longer boots due to a botched OS upgrade; I'm mounting it on an amd64 #popos box; popos is #ubuntu based. The filesystem I want to recover files from is Ext4. The Pi had two users, and I want to copy both of their user directories to my local hard drive.

I would prefer not to force a chmod or chown on the files on the USB drive.

I get errors from the GUI:

The folder "whatever" cannot be handled because you do not have permissions to read it.

I appear to have Read permissions at this level, though, judging by ls -l.

Is there a way to force my local user to have read permissions on the mounted drive without writing to the disk I'm copying from?