Re: suid bit behaviour modification in 2.6.0-test5

[Ian Hastie <lkml@ordinal.freeserve.co.uk>]

On Sunday 21 Sep 2003 01:45, Jean-pierre Cartal wrote:
> Hello,
>
> I'm running a standard RH 9 installation upgraded to kernel 2.6.0-test5
> with rpms from http://people.redhat.com/arjanv/2.5/RPMS.kernel/.
>
> I noticed that contrary to what was happening with 2.4.x kernel, suid
> root files don't loose their suid bit when they get overwritten by a
> normal user (see example below)
>
> Is this the intended behaviour or a bug ?

I got the same results.  However it seems the bug is something to do with a 
directory listing cache somewhere.  If you sync after copying over the file 
the suid bit is shown as having been cleared.

$ touch suid_test

# chown root suid_test
# chmod 4775 suid_test

$ ls -l
total 0
-rwsrwxr-x    1 root     ianh            0 Sep 22 04:21 suid_test
$ cp /bin/ls suid_test
$ ls -l
total 68
-rwsrwxr-x    1 root     ianh        69228 Sep 22 04:22 suid_test
$ sync
$ ls -l
total 68
-rwxrwxr-x    1 root     ianh        69228 Sep 22 04:22 suid_test

-- 
Ian.