* gnu/packages/patches/linux-pam-unix_chkpwd.patch: New file.
* gnu/local.mk (dist_patch_DATA): Add it.
* gnu/packages/linux.scm (linux-pam): Use it.
* gnu/system/pam.scm (pam-root-service-type): Add unix_chkpwd to setuid.
Co-authored-by: Ludovic Courtès <ludo@gnu.org>
