So if you can craft and execute an executable, and you can write to things that you already have write access to, how does that result in a privilege escalation?
If you could overlap with things you shouldn't be able to access, e.g. your kernel stack, then that makes sense. But how does being able to overlap your own user-space result in you being able to do anything you previously couldn't?
A better link would have been https://www.qualys.com/2017/09/26/cve-2017-1000253/cve-2017-... which also explains an actual exploit.
Most (all?) major distributions (that were affected) have already released patched kernel packages.
>he loader could allow part of that application's data segment to map over the memory area reserved for its stack, potentially resulting in memory corruption
do they expect an attacker to redirect code execution to an address on the stack which they previously wrote when loading the binary, so they can make use of suid to escalate priveliges ?
