Re: /proc filesystem allows bypassing directory permissions on Linux

[psz@xxxxxxxxxxxxxxxxx]

Dear Casper and Dan,

> If you can control<pid>, then clearly you have access the file anyway
> simply by controlling it using a debugger.

Sorry, but no. The "attacker" has the file opened O_RDONLY, and cannot
"upgrade" that to O_RDWR.

Cheers, Paul

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