My perspective suggests that this bug might have came from upsteam. I'm running DEBIAN 9 in VMware Workstation 12.5.9 build-7535481 and having this exact same issue.
AFFECTED = Linux 4.9.0-8-686-pae #1 SMP Debian 4.9.110-3+deb9u4 (2018-08-21) i686 GNU/Linux NOT affected = Linux 4.9.0-7-686-pae #1 SMP Debian 4.9.110-3+deb9u2 (2018-08-13) i686 GNU/Linux -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1788321 Title: swapon failed: invalid argument Status in linux package in Ubuntu: Confirmed Status in util-linux package in Ubuntu: Invalid Bug description: Environment: - Ubuntu 18.04.1 LTS - Linux 4.15.0-32-generic i686 Description: When I try to mount my swap partition or my swap file, I get "swapon failed: invalid argument" . Steps to reproduce: 1) sudo bash 2) dd if=/dev/zero of=/swapfile bs=1024 count=524288 3) mkswap /swapfile 4) chown root:root /swapfile 5) chmod 0600 /swapfile 6) swapon /swapfile Last execution returns "swapon failed: invalid argument" . I'm almost sure it's a bug because I have no problems using Linux 4.15.0-29-generic instead of Linux 4.15.0-32-generic. Also, no problems using Ubuntu 18.04.1 LTS Live CD. Regards. To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1788321/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp