File permission change automatically

After uploading successful, using default Upload library the file is saved in 'only read mode' in server directory, using chmod native function i change the file permission manually.
The question is why the file is not saved with it's default permission mode?
Operating system: Ubuntu

Thank you

Have you talked to your hosting provider about the issue? They can help you for chmod settings. I believe, it's not about Codeigniter.

@alamkhan,

I agree with @demyr. Check with your hosting provider and see what their default settings are. Also keep in mind that you could automate setting the files permissions every time a file is uploaded (just a thought). Just make sure that the file is from a trusted source.