Re: Bug in chown -- always kills suid/sgid bits.

Matthias Urlichs (smurf@work.smurf.noris.de)
2 Jun 1997 04:55:14 +0200

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Greg Alexander <galexand@sietch.bloomington.in.us> writes:
>
> Maybe a new syscall, real_chown(2)? The current chown is obviously not
> correct. :)
>
That real_chown is easily implemented by way of stat()ing the file before
the change, and re-setting the appropriate bits afterwards if necessary.

Anyway, clearing the s bits is a Good Thing for security reasons.

I also really like the symlink security patch which prevents the kernel from
following symlinks in a directory with the t bit set.

-- Time Lords say, "Go ahead, make my yesterday"

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