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Re: /proc filesystem allows bypassing directory permissions on Linux
File permissions allow everybody write access to the file.
The path via /proc to the file has been created when the initial path
via /tmp was wide open.
Closing the initial path via /tmp has no effect on the /proc path
And due to the actual file permissions the read-only fd can easily
changed to read-write.
Sent from my iPhone 3G(s)
On 26 okt 2009, at 22:58, psz@xxxxxxxxxxxxxxxxx wrote:
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.
Paul Szabo psz@xxxxxxxxxxxxxxxxx http://www.maths.usyd.edu.au/u/psz/
School of Mathematics and Statistics University of Sydney