Re: Security question: "Text file busy" overwriting executables but not shared libraries?

[Pablo Alcaraz <pabloa@laotraesquina.com.ar>]

Whatever will be the chosen solution, it would have to allow to 
overwrite all the executables and libraries files (if we have enough 
permissions).

Because:

- If I overwrite a shared library and then one running program crash, it 
will be my fault (as system administrator) or mistake.. ;-)

- It is probable that one file library is updated within one more global 
update, then probably I restart later the new demon or program. So if 
the program crash I'll fix the problem eventually.

- The previous version of a file library that I am replacing can depend 
on another file that the installer of the new version of the program 
simply erases it. For example:

a.so depends of b.so

but

a_new_version.so does not depend of b.so.

When I or an installer install the new program version, me or the 
installer erase b.so because the new version doesn't use it.

So, that it matters if a program can or can't access to the old version 
of a.so if b.so was erased?

And eventually, if I decide to update a library, I would have to do it 
(I suspect it would be the same case with executables files). It doesn't 
the matter if the change implies a fault in a running program.


It can be that this serves so that a hacker can attack the system... or 
I could hang a program when this is not my objective. Maybe a flag in 
/proc/somewhere would be am useful thing:

- if it's 1, I can overwrite all the libraries and executables files (If 
I've permission, etc.);

- if it's 0, I can not overwrite anything If it's in use.

I only want that everybody respect my right to do the wrong or stupid 
thing. This is an system administrator right :-)


Pablo