GHSA-67r7-8m5w-22wx: util-linux LIBMOUNT_FORCE_MOUNT2 allows nosuid and noexec bypass

util-linux is a random collection of Linux utilities. In util-linux 2.39.1 through 2.41.4 and 2.42 through 2.42.1, the SUID mount utility reads the attacker-controlled LIBMOUNTFORCEMOUNT2 environment variable with getenv(), allowing a local low-privileged user to force the non-atomic legacy bind-mount path. With an /etc/fstab bind mount authorized by user or users and protected by nosuid, noexec, or nodev, an attacker can race the window between the initial bind mount and the remount that applies those security flags and execute a SUID program from the temporarily unprotected mount, potentially gaining root privileges. This issue is fixed in 2.41.5 and 2.42.2.