sed -rn '/\[keys2\]/,/^\[/p' file.txt
Why aren't physically-local attacks in Chrome's threat model?
[...]
We consider these attacks outside Chrome's threat model, because there is no way for Chrome (or any application) to defend against a malicious user who has managed to log into your computer as you, or who can run software with the privileges of your operating system user account.
Почему grep regex не работает без экранирования?
3.6 Basic vs Extended Regular Expressions
=========================================
In basic regular expressions the meta-characters ‘?’, ‘+’, ‘{’, ‘|’,
‘(’, and ‘)’ lose their special meaning; instead use the backslashed
versions ‘\?’, ‘\+’, ‘\{’, ‘\|’, ‘\(’, and ‘\)’.grep -E или egrep чтобы получить extended синтаксис по умолчанию. 
chown: неверный пользователь: «user1001:1000»
