Snow Leopard guest account bug deletes user data - Page 3

I dont think the bug as reported could be true.


user logs in as guest.
Logs out.
Operating system asks if he wants to delete folder.
Ok, and it deletes.

At that stage the deletion code can have no rights to remove the default home folder. The process will be running as the user logged in.

Furthermore nobody has reported that is took a real long time to log out of their guest account - a sure sign of stuff being deleted from a larger account. It could take minutes, even up to half an hour, to delete a home dir. They dont do anything special with regards to API afaik, so they traverse the directory list, and delete filenodes.

However something then happens on login. It is possible that the existence of the guest user has somehow changed the user_ids elsewhere in the system. And that the user is logging into an account with a uid of (say) 502, not 501 - which would create a new home folder.

If anybody on these forums - which are large - sees this can you confirm anything like this.

That means the data could be there. Certainly recoverable in most cases.

Interesting point. Very interesting, actually.

:c B-but I haven't got a backup drive. *keeps forgetting to buy one*

Anyways, I hope this'll get fixed soon. (I don't use the Guest Account, but still)

Provoking the bug is reportedly a much more complex task than you describe; the fault may occur when the user logs into another account after being inside the guest account. Although anecdotal reports about the problem don't always mention this, bear in mind that people may not accurately remember every step they took before the problem happened, especially given how worried they are likely to be when they realise there's something wrong with their regular user account.

If the home folder really is deleted when the user logs into the guest account and is running under guest account privileges only then yes, this points to an extremely alarming and severe failure of the system - the underling Unix permissions model should completely and utterly preclude such a thing from happening.

As for backups... I did run Time Machine just before upgrading myself, but since my backup drive is in an eSATA enclosure driven by an unbranded SIL3132-based PCIe card, I can no longer access the volume in Snow Leopard. Annoyingly, even in 32-bit mode the driver model has changed sufficiently to break the SIL3132 driver. Silicon Image did recently release a beta driver for Snow Leopard but it does nothing on my machine - System Profiler claims that no driver is loaded for the card and the drive enclosure shows no sign of being woken up. I'm buying a FirmTek card to replace it, but having a significant hardware cost is a PITA.

I knew about the 3132 problems before upgrading, but it's one example of many small niggles with Snow Leopard that cumulatively could end up giving it a bad reputation. Leopard had its fair share of bugs too - in fact I'm not sure it ever felt as cohesive or stable as the last iteration of Tiger, particularly when it came to X11 or network shares - so perhaps this is to be expected. However, given that Apple's marketing department advertised Snow Leopard as a "fix all the bugs" release, it's really disappointing (if unsurprising) to end up with an OS that seems to be at least as unstable in its earliest incarnation as its predecessor - even if the under-the-hood changes might be very valuable for the future and explain why these instabilities are happening in the present. It's little comfort for those with computers which fail to perform as they expect under the new OS.

The home folder deletion bug looks sufficiently obscure that one might excuse Apple for letting it slip through QA, except if Apple had used a more appropriate technology (e.g. tmpfs) to implement the guest account in the first place, they wouldn't have needed to delete files upon logout and no such fault could ever have arisen. It could well be that the bug points more to fundamental architectural problems in this part of the OS than it points to QA problems.

Yep. So it happens on login to the default a/c. why?

Anybody know where the modern version of NetInfo is on 10.6?

There's no way to know for sure, but people have theorised that for some reason the deletion of guest account files gets delayed. The user logs into (or possibly out of) their usual account and then the OS decides to delete the "current user's" files. It all sounds a bit implausible though. For one thing, the deletion of the guest account 'home' folder is one rare time where a hard-coded path name would seem like a good idea (that is, use something along the lines of "rm -rf /Users/Guest", rather than "rm -rf ~"). That way, regardless of who the user ended up logged in as, it really should only be possible to delete the guest's files. Clearly that's not the case here though!

well after great deliberation and long hours of calculations I have determined that one (1) out of ten (10) engineers at apple are idiots. simple in your face situations are forgotten to fix because they are left on another persons desk over night. meanwhile they have gone on vacation....IDIOT.

We really don't know what the case is yet. The problem seems to be isolated to a handful of users and not readily reproducible, which suggests that it's not a general fault in the OS but something deeply obscure.

rdiff-backup has worked perfectly fine for me for years (well before Time Machine existed).

Stumbled across this article on http://www.dailytech.com/article.aspx?newsid=16478

I didn't see this on the front page in AI, maybe I missed it. Oh yeah, time to wait for 10.6.3 before I update?

I don't get it. Is this a joke?

Fixed the smiley for you.

So let me get this straight...you let people into your house that you don't trust? How do you know they won't be looking at or downloading illegal material? Or stealing your stuff? Or going through your bank statements?

And you could just set up one alternative account for guest use - you wouldn't have to set up individual accounts for every person in front of them (though that kind of defeats the purpose of the guest account, but may be a good temporary workaround for now).


Maybe you should look at the Time Machine reviews in the store at apple.com


Apart from in software and hardware...and software and hardware prices...

It helps to maintain perspective on the issue.

Fewer than 100 Snow Leopard users have reported experiencing data loss. During its launch weekend Apple sold 2 million copies of SL. The bug is extremely rare, and it's still undetermined as to whether files are actually erased or just moved.

It's embarrassing for Apple, but even a critical bug on SL seems to be rather elusive and for most users, impossible to replicate. No wonder Apple's been downplaying it. A fix is on the way, anyway.

Nole, all PC users in a country have the same options.



Rounding up to 100 and keeping SL at the 2M for the weekend as if they didn't sell more, that is a problem affecting 0.00005% of users, or not affecting 99.99995% of users. What percentage of the Sidekick users were affected?


PS: This problem happened to me many many months ago in the Beta, but after a restart my home foldeemr was restored. I think it's losing the link to the folder but your contents are not actually being deleted.

Would love to have this confirmed. But since it's difficult to reproduce in the fist place I wouldn't bet on it.

No help. I still don't know what you are talking about. The only thing I can imagine is that you didn't read anything in this thread before posting, or were making a weak joke.


Maybe you shouldn't, if you don't know what to do with anecdotal evidence.

Whilst I feel very sorry for the people who have lost data (and hope they did keep a backup), I actually think things like this are a useful reality check for us Apple types from time to time.

With all of Apples "it just works" marketing, I get complacent fairly often, forgetting that for all Mac OSX is a lot better than Windows, it's still an operating system created by humans, and hence could have some faults.

I don't connect my external drive to do a Time Machine backup as often as I should, and since I use guest account, this has been the wakeup I needed to start doing the backups like I should be doing anyway.

But try it for yourself.

Install OS X 10.5.8 or run it off a test partition. Activate the Guest account there, make sure it works. Then run the SL upgrade. After the upgrade, log into the Guest account and use it. Log out and back into your main account, and you'll likely find all the data will still be there. Then try it via fast user switching. You can bet your data will still be there.

The bug exists, but whether it deletes your data on your main account or simply breaks your direct access to it is still unclear. Nor does the bug affect everyone who had a Guest account in 10.5. Most users will not be able to in any way, shape or form reproduce this bug.

But the moment someone even hints at a "bug" in an Apple OS, everyone is all over it, even if only a handful of users have reported it. When you make the best OS in the biz, any hiccups are magnified a hundredfold. With Windows, bugs and critical flaws are a given. With OS X, they're shocking because they're such a rarity. The exception proves the rule. Such is the OS game.