Re: /proc filesystem allows bypassing directory permissions on Linux

[psz () maths usyd edu au]

Tony Finch <dot () dotat at> wrote:

> Attacker opens [directory] and waits. ...
> Attacker uses openat() to open and modify the "private" file.

Surely if the permissions do not allow lookup then openat() will fail.
[The attacker opened directory when it was searcheable; then permissions
were closed; then attacker attempts openat().] Surely directory contents
are not cached??!!

Cheers, Paul

Paul Szabo   psz () maths usyd edu au   http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics   University of Sydney    Australia