Corrupted gshadow files with many users in group

[Bill Gradwohl]

Mike Cisar wrote:

>Have a system running FC2 and have recently noticed problems with the
>gshadow file becoming corrupted on groups with a large number of members
>(100+).
>
>I seem to recall seeing a similar problem years back (RH7, RH8 era) which
>affected both the group and gshadow files... a 3rd party made a patched
>version of something which solved the problem, and then eventually the
>problem was resolved in the distribution.  The details are all very fuzzy by
>now :-)
>
>After a certain period the gshadow becomes corrupted to such an extent that
>using useradd, userdel, etc brings the machine to its knees for maybe 10
>minutes using all swap and all ram and driving utilization through the roof
>and then it thankfully recovers.
>
>The corruption seems to be bits and pieces of the particular group repeated
>over and over, with the valid entries all the way at the end of the line.
>As an example, on this machine the netexplorer group has around 100 users...
>after the line in gshadow became corrupted I simply snipped the whole line
>leaving the entry as (the entry in the group file was fine with all users
>intact).
>
>netexplorer:!::
>
>I then added a user "acall" to the group, it was added successfully to the
>group file, but gshadow now contained the following... 
>
>netexplorer:!::orer,lorer,,,er,,,lorer,,,lorer,,,orer,plorer,!,rer,orer,!,or
>er,orer,!,,er,,,,,,,,,acall
>
>adding a second user "gptest" leaves the gshadow entry in this state...
>
>netexplorer:!::orer,lorer,,orer,er,,r,lorer,,orer,lorer,,orer,orer,plorer,!,
>rer,orer,!,orer,orer,!,,er,rer,,,,lorer,lorer,er,r,orer,lorer,,,er,,,lorer,,
>,lorer,,,orer,plorer,!,rer,orer,!,orer,orer,!,,er,,,,,,,,,acall,gptest
>
>As you can see this can snowball the length of the line in no time.
>
>Any ideas, suggestions?
>
>Thanks,
>  
>
>>>>>>Mike <<<<<
>>>>>>            
>>>>>>
>
>  
>
I bugzilla'd that problem a few days ago after I described the same 
issue on this list. I forget the bugzilla number. Its been assigned but 
there is no fix yet.

I manually fixed the gshadow file using sed, grep, and a bit of manual 
keying to put it in shape. The bulk of the file can be shrunk down by 
just removing consecutive commas.

-- 
Bill Gradwohl
bill at ycc.com
http://www.ycc.com
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