Stupid bug

[DukePuke]

Ok, i will explain more shit. I dont like one thing in linux (currently having 2.4.20 version of kernel, but if this bug is kernel problem, it is too shine to miss it).

===================================
Then i work with linux (for example login as root), and do startx, do graphic interface, etc, browse net and so on.

And I plan to change user. I logout, to the text environment, login user, password, everything is ok.

i do startx.

I see strange view during X startup for about 2 seconds. Lets say you divide your screen in 2 equal parts. Top part, and bottom part.  And you, during those 2 seconds, see black in top part, and in bottom part you see... half of screenshot, which was made before last session logout. yes, half of screenshot.  

So imagine, you login as root, launch X interface, and watch porn. And you logout of system, and shutdown PC. Next day some kind of user will turn up comp, login in HIS account, and he will see view of gmplayer, playing porn movie, (in bottom part of screen) for 2 seconds, after that X interface will be ready and that user will do stuff in his account.  

Thats damn hole, lack of privacy, to avoid serious shit you have to close all windows before logout, cuz some kind of user can see *important document* or email letter, or smth.. well i hope you understood this, and probably even encountered this problem themselves

[Refalm]

Well, that's because xfree86 isn't bugfixed and updated as much as we all like to.

[WMD]

You shouldn't be using root at all.

[flap]

Incidentally, you should never need to login to X as root.

[DukePuke]

Yes damn who cares, thats just example, but user data have to be protected too. Linux is multi-user operating system, so btw its threat that user can see other user stuff, and what he done before logout.. this *should* not to be ,damn.. And the thing its appears even after restart/shutdown, means this screenshot is stored in HDD, btw and where, if other user can access it?

[DukePuke]

damn cant understand, is this problem just for me? Its not actual for you?

[Calum]

duke,
let me clear something up.

you appear to be saying that linux has a bug and allows a privacy violation which is due to this thing that you describe. I have also noticed this by the way, it is indeed actual for me in many operating systems.

Now. you say this is the fault of "linux". Rubbish. This is the fault of "XFree86" which is an ancient piece of software which is still used as the default platform for graphical user interfaces under most *IX environments. This is good software and is fully network aware, or it would not still be being used all this time later. That said, there are limits. A lot of the things people no want from X were never dreamed of when the project was started. In a lot of ways X is a hack job, and the fact it does so well despite this shows that generally it works well.

As Refalm says X is buggy in a lot of ways, in my opinion this is because it has reached its limit, and something else should be actively developed to provide a network aware GUI framework, whereupon X can be phased out.

BUT this bug has NOTHING to do with linux. linux is not insecure simply because you choose to run X on it. X is applications level software, and has NOTHING to do with the system. you install a system, you choose what applications software to put on it. At the harshest end, either put up with the software that's available or rewrite the software so you are happy with it. Myself i am surprised nobody has fixed this in X already, or perhaps its an unfixable or particularly awkward bug, i don't know.

So there you go. Yes it exists, no it has nothing to do with linux, even though yoru linux operating system came packaged with this buggy software.

[mobrien_12]

Duke,

If one uses a Graphical Login system such as XDM, GDM, or KDM, then this will not happen.

What is happening is that the graphics card is engaged, and it displays the contents of the video RAM.  If there is previous data in video RAM, it will be shown for the short time before the X Server puts new data in the Video RAM.

Using graphical logins means that video ram will be overwritten with the login screen.  

I don't remember seeing this with the proprietary NVIDIA driver, propbably because it puts the  NVIDIA logo up.

I never really thought about it before until you posted it.  For the sake of security privacy, it would probably be good to flush the video buffer before engaging the display. I'd suggest that you tactfully submit the idea to www.xfree86.org, but they seem to be going a little nuts lately.  Maybe the guys at Xorg would appreciate it.

[ May 07, 2004: Message edited by: M. O'Brien ]

[hm_murdock]

x.org is much better. from what I've heard, it's very, very nice.

[flap]

quote:What is happening is that the graphics card is engaged, and it displays the contents of the video RAM. If there is previous data in video RAM, it will be shown for the short time before the X Server puts new data in the Video RAM.

He reckons it happens between reboots.

[DukePuke]

Ok, thanks for explaining this shit (expecialy for Colum) but btw todays linux is engaging in desktops to fight with M$ windoze, so btw this (bug) needs to be fixed, cuz its not even funny

[flap]

I doubt many people will encounter that problem, since people who use X generally boot straight into it, rather than booting into text mode and using startx.

[DukePuke]

i am slackware user, and this type of login is by default in there. There are tons of slackware users on earth, and even more who uses this. Well maybe that xfree666 or smth is updated, and i have old version of this.. btw

[flap]

I'm a slackware user and I boot straight into X. I'd have thought that the vast majority of people who use X at all (on any distro) would be booting into that runlevel.

[Refalm]

quote:flap: I'm a slackware user and I boot straight into X. I'd have thought that the vast majority of people who use X at all (on any distro) would be booting into that runlevel.

I don't. I think it's faster to login at 3 and just type "startx".