glEnable(GL_CULL_FACE);
glCullFace(GL_BACK);

I have been trying to implement deferred rendering for 2 weeks. But all of the meshes in my test program are culled reversely. The code above should be the correct way to render a model. Every example i looked at draws the objects like that. But here is the result when i use GL_BACK as cull face:

And this is the GL_FRONT:

GL_FRONT should have been the result i expected from GL_BACK. Strange thing is when I set glFrontFace to GL_CW, everything disappears. So this problem is not about winding. I spent all my day on searching information about this. Only thing i found is something about depth buffers. But I can't see any problems in creation. Just because of this problem, I can't correctly do stencil pass for spot light rendering. I enable GL_DEPTH_TEST in geometry pass. This is what i attach to my fbo as depth buffer

glGenRenderbuffers(1, &depthTexture);
glBindRenderbuffer(GL_RENDERBUFFER, depthTexture);
glRenderbufferStorage(GL_RENDERBUFFER, GL_DEPTH24_STENCIL8, width, height);
glFramebufferRenderbuffer(GL_FRAMEBUFFER, GL_DEPTH_STENCIL_ATTACHMENT, GL_RENDERBUFFER, depthTexture);

The main question is, what are the possibilities that would cause a reversed backface culling ?