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Re: cdrecord-2.01.01a21 refuses work on Linux 2.4 if non-ide-scsi DVD-ROM is present



Joerg Schilling wrote:
scdbackup@gmx.net wrote:

Hi,

update and probably final report about the setuid problem on
SuSE 9.3 :

Joerg was right: with setuid bit the program is not
running as "root" but geteuid() returns the UID of
the previous owner of the file "thomas".

The problem seems bound to a single ext3 partition and
even there it is not easy to reproduce.
Any of the following actions make it vanish:
- copy binary to different partition and execute there.
- copy binary to different partition, copy back
  and execute at its old storage location.
- apply  chown root  once again after chmod u+s
  (older chown implementations cleared setuid
   bit and thus i first chown and then chmod).

If you (thomas) have been able to chmod u+s on a file owned by root,
then something looks broken.

What I remember is that the s-bit clearing was done different from UNIX
on previous Linux versions (chown root on a suid file did not clear the s-bit as in UNIX).

Agreed, that policy was changed at some point in the fairly distant past, at least in the mainline kernel. Distributions have their own ideas, of course.

--
E. Robert Bogusta
 It seemed like a good idea at the time



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