You can buy a gallon can of roof cement and a cheap putty knife for under $10 at Home Depot. Or get a caulk tube of it (and a caulk gun) for about the same amount. Gloves suggested 'cause this stuff is messy. It's gonna be dry by tomorrow and in my experience patching when wet just never works out for long. Tell your landlord you repaired it yourself without disturbing him during his emergency and I'd bet he'll happily reimburse you for the materials. I sure would...

Good luck-

If you've truly found the source of the leak, that's the hard part.
Home Depot sells roofing cement, some in caulk tubes probably, that can be applied onto wet surfaces. Apply it with a plastic trowel and wear disposable gloves. Maybe even a little fiber tape to span a gap. That is really all a roofer will do, unless there is a whole area that needs to be reflashed, or something.
Here's the idea.

If you want to hold it over for a few days until your landlord return, just put a tarp over the area with the crack and weight the corners down with sandbags / bags of rice / etc. Of course, this will depend on the pitch of your roof to work properly.

Our skylight was leaking sometime ago, and while we waited for a new skylight to be ordered/made/delivered, we had a tarp over it, and it held out really well, and for a long time.

Hope this helps, and good luck!

My roof has a small leak. Normally, i would just call my landlord and have him deal with it........but he is away and dealing with a family emergency and won't return until first week of November. Sure, I could call him and all that jazz but he is always been an awesome landlord and not a slum lord that you hear about all the time....so i figure i could wait a bit.

The other tenants ceilings are fine and they even double checked. It's just my place that is cursed. I went up in the roof and checked it and observed it when it drizzled(these last two days) and found the small crack.

Is there anything i could do to seal it? Is there a salve that i can apply....even little old me who knows nothing about home repair??? And it only leaks when its a small drizzle or light rain.......that is just so odd.

Any info is appreciated.