RDMA/rxe: Fix memory leak in error path code

In rxe_mr_init_user() at the third error the driver fails to free the
memory at mr->map. This patch adds code to do that.  This error only
occurs if page_address() fails to return a non zero address which should
never happen for 64 bit architectures.

Fixes: 8700e3e ("Soft RoCE driver")
Link: https://lore.kernel.org/r/20210705164153.17652-1-rpearsonhpe@gmail.com
Reported by: Haakon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Reviewed-by: Zhu Yanjun <zyjzyj2000@gmail.com>
Reviewed-by: Håkon Bugge <haakon.bugge@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

drivers/infiniband/sw/rxe/rxe_mr.c

@@ -113,13 +113,14 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 	int			num_buf;
 	void			*vaddr;
 	int err;
+	int i;
 
 	umem = ib_umem_get(pd->ibpd.device, start, length, access);
 	if (IS_ERR(umem)) {
-		pr_warn("err %d from rxe_umem_get\n",
-			(int)PTR_ERR(umem));
+		pr_warn("%s: Unable to pin memory region err = %d\n",
+			__func__, (int)PTR_ERR(umem));
 		err = PTR_ERR(umem);
-		goto err1;
+		goto err_out;
 	}
 
 	mr->umem = umem;
@@ -129,9 +130,9 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 
 	err = rxe_mr_alloc(mr, num_buf);
 	if (err) {
-		pr_warn("err %d from rxe_mr_alloc\n", err);
-		ib_umem_release(umem);
-		goto err1;
+		pr_warn("%s: Unable to allocate memory for map\n",
+				__func__);
+		goto err_release_umem;
 	}
 
 	mr->page_shift = PAGE_SHIFT;
@@ -151,10 +152,10 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 
 			vaddr = page_address(sg_page_iter_page(&sg_iter));
 			if (!vaddr) {
-				pr_warn("null vaddr\n");
-				ib_umem_release(umem);
+				pr_warn("%s: Unable to get virtual address\n",
+						__func__);
 				err = -ENOMEM;
-				goto err1;
+				goto err_cleanup_map;
 			}
 
 			buf->addr = (uintptr_t)vaddr;
@@ -177,7 +178,13 @@ int rxe_mr_init_user(struct rxe_pd *pd, u64 start, u64 length, u64 iova,
 
 	return 0;
 
-err1:
+err_cleanup_map:
+	for (i = 0; i < mr->num_map; i++)
+		kfree(mr->map[i]);
+	kfree(mr->map);
+err_release_umem:
+	ib_umem_release(umem);
+err_out:
 	return err;
 }