Pages owned by certain user-group show up as Internal Server Error

Today, one of the web designers who hosts a site on my server informed me that when he uploaded a new .php page, it was coming up with Internal Server Error.

When I checked the attributes of the file, it was owned by user1, but the group it was owned by was cpanelusers: a group I created a while ago in order to give two users access to eachother's files. (Long story short, one user controlled the mobile domain, the other the desktop domain, however many of the images and thumbnails used for the mobile domain were generated from files owned by the desktop domain user). The fix for that issue was to create the shared group "cpanelusers" and default newly created/uploaded files to being owned by that group.

The weird thing is, as soon as I changed the group ownership to the user1 group (along with keeping the user ownership set to the user1 user), the page loaded as expected.

I'm willing to bet that there's just something stupid in the cpanelusers group attributes that's preventing any web visitors from loading that particular .php, but I'm such a Linux newb I'm not even sure where to start looking.

Does anyone have any idea what might be causing this problem? Any tips on diagnostic approaches I could look into? Thank you.

 

I apologize for how long its taken me to get back to you, and I appreciate your help. This problem has gotten a lot stranger.

So, as I described in my initial post, pages that were being created were owned by the group 'cpanelusers' and in order to get them to load I needed to change that group ownership to the 'user1' group.

Yesterday, that completely flipped. I could not get our website to load, the homepage was giving us that Internal Server Error. When I looked in the apache error log I saw:

SoftException in Application.cpp:431: Mismatch between target GID (550) and GID (513) of file "/home/fu/bar/index.php".

A brief look through group attributes showed me that GID 513 is the 'user1' group, and GID 550 is 'cpanelusers'. I ended up bringing the website back up by changing group ownership of everything in the web folder to the 'cpanelusers' group, which, if you'll recall from my first post, was the problem configuration previously.

I've spoken to my web guys (who are the ones who write the PHP and manage the page itself) and they have not done anything to cause this sudden shift. I can not wrap my head around why one day my server would not load anything owned by the 'cpanelusers' group and the next day suddenly go down and demand that everything be owned by the 'cpanelusers' group.

To cap it all off, now when I look through the error log I'm seeing the opposite error:

SoftException in Application.cpp:431: Mismatch between target GID (513) and GID (550) of file "/home/fu/bar/index.php".

So now apache is saying that it expects that file to be owned by the 'user1' group and NOT 'cpanelusers'. The only difference today is that the website is still up and seems to be functional despite this error showing up in the logs every couple of minutes.

PS: To answer your last question, yes, we are using suPHP as our PHP handler.

 

Okay, I see what you're saying, but did you read the part of my story where that was the only way the web page would load? Where Apache was throwing all sorts of errors about the target GID not being the user group?

 

Target GID was 'cpanelusers', current GID was 'user1'. This is the error I was getting.

 

That's not what that error indicates at all. The error was specifically stating that the current setup was user1:user1, and that the TARGET GID SETUP was user1:cpanelusers.

You are right, when I run ls -al on that directory, the files are owned by user1:cpanelusers, which is contrary to the setup you are suggesting. What I'm telling you, if you actually read my description of the issue or the steps I took to fix our website downtime yesterday, was that if I use your configuration suggestion, the way it was set up BEFORE, the website GOES DOWN.

The only way to get the pages to load right now is to chown them to user1.cpanelusers, and NOT user1.user1.