CVE-2026-48983 pam_usb: TOCTOU race condition in pad directory creation allows symlink substitution

pamusb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, a symlink race condition exists in per-device and per-user pad directory creation. pamusb uses a check-then-act pattern: it calls lstat to test for existence and then calls mkdir separate...