Reading lead-in on Plextor needs root privileges?

[Tatsh]

I find this odd. It happens even if the drive is set to 0666 permissions. From strace:

ioctl(4</dev/sr1>, SG_IO,
{interface_id='S', dxfer_direction=SG_DXFER_FROM_DEV, cmd_len=12, cmdp="\xd8\x00\xff\xff\xb1\x4b\x00\x00\x00\x01\x02\x00", mx_sb_len=18,
iovec_count=0, dxfer_len=2742, timeout=50000, flags=0, dxferp= ..., 
status=0, masked_status=0, msg_status=0, sb_len_wr=0, sbp="", host_status=0, 
driver_status=0, resid=0, duration=0, info=0}) = -1 EPERM (Operation not permitted)

Am I missing a permission somewhere else?

As root this works fine. Reading an early lead-in on the LG drive works fine as a normal user.

[superg]

Permissions in general is not redumper problem, there is nothing that can be done within process scope to elevate permissions. This is something that I told you before on a discord, you need to understand which devices file of your distribution provide RW access to SCSI and how to do that. Here's more information: https://bbs.archlinux.org/viewtopic.php?id=260586 I need IOCTL read and write access, there is no way around that.

[superg]

Just to clarify, the problem is unrelated to cd writing, but it is illustrated that some SCSI commands are not allowed because they are treated as "write" to the device. The topic is quite old but illustrates the problem quite well.