On Tue, Nov 10, 2020 at 01:41:14PM -0800, Jianxin Xiong wrote: > + mr = pd->device->ops.reg_user_mr_dmabuf(pd, offset, length, virt_addr, > + fd, access_flags, > + &attrs->driver_udata); > + if (IS_ERR(mr)) > + return PTR_ERR(mr); > + > + mr->device = pd->device; > + mr->pd = pd; > + mr->type = IB_MR_TYPE_USER; > + mr->uobject = uobj; > + atomic_inc(&pd->usecnt); > + > + uobj->object = mr; > + > + uverbs_finalize_uobj_create(attrs, UVERBS_ATTR_REG_DMABUF_MR_HANDLE); > + > + ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_LKEY, > + &mr->lkey, sizeof(mr->lkey)); > + if (ret) > + goto err_dereg; > + > + ret = uverbs_copy_to(attrs, UVERBS_ATTR_REG_DMABUF_MR_RESP_RKEY, > + &mr->rkey, sizeof(mr->rkey)); > + if (ret) > + goto err_dereg; > + > + return 0; > + > +err_dereg: > + ib_dereg_mr_user(mr, uverbs_get_cleared_udata(attrs)); This isn't how the error handling works with uverbs_finalize_uobj_create() - you just return the error code and the caller deals with destroying the fully initialized HW object properly. Calling ib_dereg_mr_user() here will crash the kernel. Check the other uses for an example. Again I must ask what the plan is for testing as even a basic set of pyverbs sanity tests would catch this. I've generally been insisting that all new uABI needs testing support in rdma-core. This *might* be the exception but I want to hear a really good reason why we can't have a test first... Jason
