Can't mount non-/ partition using Thunar because of grsecurity patched 4.9.65-2 amd64 linux kernel

[TemTem <temtem@protonmail.ch>]

Hi, when using the grsecurity patched 4.9.65-2 linux kernel from stretch-backports, I can't mount other partitions in my hard disk drive using Thunar. It says I don't have the permission to mount partitions even though I am a sudoer. I tried using the kernel without the patch, and mounting using Thunar works. I think the reason why this happens is because the appropriate PaX flags aren't set in the program which displays a root prompt. If that's the case, what is the name of the program which I should set and what PaX flags should I use? I also tried mounting using the terminal, and it works, except for the encrypted partition. It seems mount doesn't recognize "crypto-LUKS". How can I make it recognize it so that I can mount my encrypted partition via terminal?